high early strength fiber reinforced...
TRANSCRIPT
SHRP-C-366
Mechanical Behavior of
High Performance Concretes, Volume 6
High Early StrengthFiber Reinforced Concrete
A. E. NaamanF. M. AlkhairiH. Hammoud
University of Michigan, Ann Arbor
Strategic Highway Research ProgramNational Research Council
Washington, DC 1993
SHRP-C-366ISBN 0-309-05618-7Contract C-205
Product No. 2014, 2023, 2024
Program Manager: Don M. HarriottProject Manager: lnam JawedProduction Editor: Cara J. Tate
Program Area Secretary: Carina S. Hreib
October 1993
key words:admixture
aggregatecompressive strengthdurability
fatiguefiber-reinforced concrete
flexural strengthhigh early strengthhigh-performance concretemodulus
portland cement concretetensile strengthtoughness index
Strategic Highway Research ProgramNational Academy of Sciences2101 Constitution Avenue N.W.
Washington, DC 20418
(202) 334-3774
The publication of this report does not necessarily indicate approval or endorsement of the findings, opinions,conclusions, or recommendations either inferred or specifically expressed herein by the National Academy ofSciences, the United States Government, or the American Association of State Highway and TransportationOfficials or its member states.
© 1993 National Academy of Sciences
I.SM/NAP/1093
Acknowledgments
The research described herein was supported by the Strategic Highway Research Program(SHRP). SHRP is a unit of the National Research Council that was authorized by section128 of the Surface Transportation and Uniform Relocation Assistance Act of 1987.
The overall research work was undertaken by a consortium of three universities, namely:North Carolina State University (prime contractor) with P. Zia (project director), S. Ahmad,and M. Lemming; the University of Michigan with A. E. Naaman (principal investigator);and the University of Arkansas with R. P. Elliot and J. J. Schemmel.
The research team received valuable support, counsel, and guidance from the Expert TaskGroup. The support and encouragement provided by Inam Jawed, SHRP project manager, isdeeply appreciated.
The authors of this report also would like to acknowledge the help of several collaboratorsin conducting various phases of the experimental investigation. They include M. Harajli(visiting professor) and graduate students P. Strzyinski, I. Khayyat, B. Campbell, S. M.Jeong, and J. Alwan. Opinions expressed in this report are those of the authors and do notnecessarily reflect the views of SHRP.
oo°
111
Contents
Acknowledgments ................................................. iii
List of Figures ..................................................... ix
List of Tables ................................................... xvii
Preface ......................................................... xix
Abstract ......................................................... 1
Executive Summary ................................................. 3
1 Introduction .................................................... 7
1.1 SHRP C-205: Mechanical Behavior of High Performance Concretes ........ 7
1.1.1 Project Overview ....................................... 7
1.1.2 Definition of High Performance Concrete (HPC) ................. 8
1.2 High Early Strength Fiber Reinforced Concrete (HESFRC) ............. 10
1.2.1 Summary
1.2.2 Organization of This Report .............................. 111.3 References ............................................... 13
2 Objectives and Scope ............................................ 15
3 Characterization of Constituent Materials ............................... 19
3.1 Cement ................................................. 19
3.2 Coarse Aggregates ......................................... 19
3.3 Fine Aggregates ........................................... 213.4 Mineral Admixtures ........................................ 21
3.5 Chemical Admixtures ....................................... 21
3.6 Other Admixtures .......................................... 21
3.7 Fibers .................................................. 21
4 Mixture Proportions ............................................. 23
4.1 Development Phase ............. •............................ 234.2 Production Phase .......................................... 23
5 Mixing and Curing Procedures ...................................... 31
5.1 Mixing Procedure .......................................... 31
5.2 Curing Procedure .. ........................................ 32
5.3 Properties of Fresh Mix ...................................... 32
6 Compression Tests .............................................. 37
6.1 Experimental Program ....................................... 37
6.2 Test Apparatus and Procedure ................................. 37
6.3 Data Analysis and Test Results ................................ 47
6.3.1 Stress versus Strain Response with Time ..................... 49
6.3.2 Stress versus Strain Response: Comparison Between Series ........ 56
6.3.3 Compressive Strength .................................. 616.3.4 Elastic Modulus ...................................... 66
6.4 Conclusions .............................................. 69
6.4.1 Stress-Strain Response in Compression ...................... 696.4.2 Elastic Modulus ...................................... 71
6.5 Recommendations .......................................... 72
6.6 References ............................................... 74
7 Bending Tests .......... ....................................... 75
7.1 Experimental Program ....................................... 75
7.2 Test Apparatus and Procedure ................................. 79
7.2.1 Apparatus ........................................... 79
7.2.2 Definition of Toughness Index ............................ 79
7.3 Data Analysis and Test Results ................................ 84
7.3.1 Load versus Deflection and Strain Capacity Response with Time .... 84
7.3.2 Load versus Deflection Response: Comparison Between Series ...... 94
7.3.3 Modulus of Rupture or Maximum Flexural Strength ............ 1017.4 Conclusions ............................................ 111
vi
7.5 Recommendations ......................................... 114
7.5.1 Recommendations Based on Strength Criteria ................. 114
7.5.2 Recommendations Based on Energy Absorption (Toughness) Criteria 1157.6 References .............................................. 117
8 Splitting Tensile Tests ........................................... 119
8.1 Experimental Program ...................................... 119
8.2 Test Apparatus and Procedure ................................ 119
8.3 Data Analysis and Test Results ............................... 125
8.4 Conclusions ............................................. 130
8.5 Recommendations ......................................... 134
8.6 References .............................................. 136
9 Fatigue Tests ................................................. 137
9.1 Experimental Program ...................................... 137
9.2 Test Apparatus and Procedure ................................ 139
9.3 Data Analysis and Test Results ............................... 143
9.3.1 Dynamic Modulus of Elasticity ........................... 146
9.3.2 Fatigue Life and Endurance Limit ......................... 146
9.3.3 Fatigue Life and Endurance Limit: Comparison with
Other Investigations ................................ 147
9.3.4 Hysteretic Load versus Deflection Response .................. 149
9.3.5 Load versus Tensile Strain Capacity ....................... 1519.4 Conclusions ............................................. 156
9.5 Recommendations ......................................... 156
9.6 References .............................................. 157
10 Summary and Recommendations ................................... 159
10.1 Compression Tests ........................................ 159
10.2 Bending Tests ........................................... 160
10.2.1 Recommendations Based on Strength Criteria ................ 161
10.2.2 Recommendations Based on Energy Absorption
(Toughness) Criteria ............................... 161
10.3 Splitting Tensile Tests ...................................... 162
10.4 Fatigue Tests ............................................ 163
10.5 Recommendations for Future Research .......................... 163
vii
Bibliography .................................................... 165
Appendix A: Compression Tests ...................................... 171
Appendix B: Bending and Tensile Tests ................................. 251
Apppendix C: Fatigue Tests ......................................... 277
o,,VIII
List of Figures
Fig. 4.1 - Flowchart Showing Classification of the Mixes Used ............................... 24
Fig. 4.2 - Mix ID Code .................................................................................................... 26
Fig. 6.1 - Flowchart of the Compression Experimental Program .................................. 39
Fig. 6.2 - Specimen ID Code ........................................................................................... 40
Fig. 6.3 - Test Set-up for Measurement of Elastic Modulus ........................................... 42
Fig. 6.4 - Test Set-up Used to Determine the Stress-Strain Response
in Compression ............................................................................................... 43
Fig. 6.5 - Stress vs. Strain Response of Control Mix with Time .................................... 50
Fig. 6.6 - Effect of Cylinder Size on the Stress-Strain Response
of the Control Mix ........................................................................................... 50
Fig. 6.7 - Stress vs. Strain Response of Mix A1%S3 with Time ................................... 51
Fig. 6.8 - Effect of Cylinder Size on the Stress-Strain Response of Mix A1%S3 .......... 51
Fig. 6.9 - Stress vs. Strain Response of Mix A2%S3 with Time ................................... 53
Fig. 6.10 - Effect of Cylinder Size on the Stress-Strain Response of Mix A2%S3 ........ 53
Fig. 6.11 - Stress vs. Strain Response of Mix A 1%S5 with Time ................................. 54
Fig. 6.12 - Effect of Cylinder Size on the Stress-Strain Response of Mix A1%S5 ........ 54
Fig. 6.13 - Stress vs. Strain Response of Mix A l%P0.75 with Time ............................ 55
Fig. 6.14 - Effect of Cylinder Size on the Stress-Strain Response
of Mix AI %P0.75 ......................................................................................... 55
Fig. 6.15 - Stress vs. Strain Response of Mix A2%P0.75 with Time ............................ 57
Fig. 6.16 - Effect of Cylinder Size on the Stress-Strain Response
of Mix A2%P0.75 ......................................................................................... 57
Fig. 6.17 - Stress vs. Strain Response of Mix AI%S3S5 with Time ............................. 58
ix
Fig. 6.18 - Effect of Cylinder Size on the Stress-Strain Responseof Mix A 1%S3S5 .......................................................................................... 58
Fig. 6.19 - Stress vs. Strain Response of Mix A2%S3S5 with Time ............................. 59
Fig. 6.20 - Effect of Cylinder Size on the Stress-Strain Response
of Mix A2%S3S5 ......................................................................................... 59
Fig. 6.21 - Effect of Fiber Type on the 1 Day Stress-Strain Response (Vf=l%) ........... 60
Fig. 6.22 - Effect of Fiber Type on the 28 Day Stress-Strain Response (Vf=l%) ......... 60
Fig. 6.23 - Effect of Using 2 Types of Fiber on the 28 Day Response (Vf=l%) ........... 62
Fig. 6.24 - Effect of Using 2 Types of Fiber on the 28 Day Response (Vf=2%) ........... 62
Fig. 6.25 - Compressive Strength, f'c vs. Time (Vf=l%) .............................................. 64
Fig. 6.26 - Compressive Strength, f'c vs. Time (Vf=2%) .............................................. 64
Fig. 6.27 - Compressive Strength, f'c _,s.Time, 50/50 Steel Fibers, (Vf=l%) ............... 65
Fig. 6.28 - Compressive Strength, f'c _,s.Time, Polypropylene Fibers, (Vf=l%) ......... 65
Fig. 6.29 - Elastic Modulus, Ec vs. x/f'c ........................................................................ 67
Fig. 6.30 - Elastic Modulus, Ec vs. Time, (Vf=l%) ....................................................... 68
Fig. 6.31 - Elastic Modulus, Ec vs. Time, (Vf=2%) ....................................................... 68
Fig. 7.1 - Flowchart of the Flexural Experimental Program ........................................... 77
Fig. 7.2 - Specimen ID Code ........................................................................................... 78
Fig. 7.3 - Sketch of the Test Set-up for Flexural Tests ................................................... 80
Fig. 7.4 - Test Set-up for the Flexural Tests ................................................................ 81
Fig. 7.5 - Instrumentation Used for the Flexural Tests ................................................... 82
Fig. 7.6 - Toughness Index in Bending: top) Definition for an Elastic Perfectly
Plastic Response; bottom) Typical Curves for FRC ....................................... 83
Fig. 7.7 - Effect of Time on Load vs. I-)eflection Response,
50/50 Steel Fibers, (Vf=1%) ........................................................................... 88
Fig. 7.8 - Effect of Time on Load vs. Deflection Response,
30/50 Steel Fibers, (Vf=1%) ........................................................................... 88
Fig. 7.9 - Effect of Time on Load vs. Deflection Response,
30/50 Steel Fibers, (Vf=2%) ........................................................................... 89
Fig. 7.10 - Effect of Time on Load vs. Deflection Response,
1/2" Polypropylene Fibers, (Vf--0.15%) ....................................................... 89
Fig. 7.11 - Effect of Time on Load vs. Strain Capacity Response,
1/2" Polypropylene Fibers, (Vf=0.15%) ...................................................... 90
Fig. 7.12 - Effect of Time on Load vs. Deflection Response,
1/2" Polypropylene Fibers, (Vf=1%) ............................................................ 90
Fig. 7.13 - Effect of Time on Load vs. Deflection Response,
1/2" Polypropylene Fibers, (Vf=2%) ............................................................ 91
Fig. 7.14 - Effect of Time on Load vs. Deflection Response,
30/50 + 50/50 Steel Fibers, (Vf=2%) ............................................................ 92
Fig. 7.15 - Effect of Time on Load vs. Strain Capacity Response,
30/50 + 50/50 Steel Fibers, (Vf=2%) ............................................................ 92
Fig. 7.16 - Effect of Time on Load vs. Deflection Response,
Latex, 30/50 + 50/50 Steel Fibers, (Vf-1%) ................................................. 93
Fig. 7.17 - Effect of Time on Load vs. Strain Capacity Response,
Latex, 30/50 + 50/50 Steel Fibers, (Vf=l%) ................................................. 93
Fig. 7.18 - Load vs. Deflection Response for Different Mixes, 1 Day,
Plain FRC, (Vf=1%) ..................................................................................... 95
Fig. 7.19 - Load vs. Strain Capacity Response for Different Mixes, 1 Day,
Plain and Hybrid FRC, (Vf--l%) .................................................................. 95
Fig. 7.20 - Load vs. Deflection Response for Different Mixes, 28 Days,
Plain FRC, (Vf=1%) ..................................................................................... 96
Fig. 7.21 - Load vs. Strain Capacity Response for Different Mixes, 28 Days,
Plain and Hybrid FRC, (Vf=1%) .................................................................. 96
Fig. 7.22 - Load vs. Deflection Response for Different Mixes, 1 Day,
Plain FRC, (Vf=2%) ..................................................................................... 98
xi
Fig. 7.23 - Load vs. Strain Capacity Response for Different Mixes, 1 Day,
Plain and Hybrid FRC, (Vf-2%) .................................................................. 98
Fig. 7.24 - Load vs. Deflection Response for Different Mixes, 28 Days,
Plain FRC, (Vf=2%) ..................................................................................... 99
Fig. 7.25 - Load vs. Strain Capacity Response for Different Mixes, 28 Days,
Plain and Hybrid FRC, (Vf=2%) .................................................................. 99
Fig. 7.26 - Effect of Additive on Load vs. Deflection Response, 1 Day,
50/50 Steel Fibers, (Vf=l%) ......................................................................... 100
Fig. 7.27 - Effect of Additive on Load vs. Strain Capacity Response, 1 Day,
50/50 Steel Fibers, (Vf=1%) .......................................................................... 100
Fig. 7.28 - Modulus of Rupture fr vs. Time for Different Mixes, (Vf=l%) ................... 102
Fig. 7.29 - Modulus of Rupture fr vs. Time for Different Mixes, (Vf=2%) ................... 102
Fig. 7.30 - Toughness Index 15and I10vs. Time, 30/50 Steel Fibers, (Vf=l%) ............. 105
Fig. 7.31 - Toughness Index I5 and I10vs. Time, 30/50 Steel Fibers, (Vf--2%) ............. 105
Fig. 7.32 - Toughness Index 15and II0 vs. Time, 50/50 Steel Fibers, (Vf=l%) ............. 106
Fig. 7.33 - Toughness Index I5 and 110vs. Time,
1/2" Polypropylene Fibers, (Vf=l%) ............................................................ 106
Fig. 7.34 - Toughness Index I5 and I10vs. Time, 50/50 Steel Fibers,
Latex, (Vf=1%) ............................................................................................. 107
Fig. 7.35 - Toughness Index I5 and I10vs. Time, 30/50 Steel + 50/50 Steel
Fibers, Latex, (Vf=1%) ................................................................................. 107
Fig. 7.36 - Toughness Index I5 and I10 vs. Time, 1/2" Polypropylene Fibers,
Latex, (Vf=l%) ............................................................................................. 108
Fig. 7.37 - Toughness Index I5 and 110vs. Time, 50/50 Steel Fibers,
Silica Fume, (Vf--1%) ................................................................................... 108
Fig. 7.38 - Toughness Index I20-co vs. Time for Different Mixes, (Vf=l%) ................. 109
Fig. 7.39 - Toughness Index I20 -Ist-CR vs. Time for Different Mixes, (Vf--l%) ........... 109
Fig. 7.40 - Toughness Index I.5-co vs. Time for Different Mixes, (Vf=l%) .................. 110
xii
Fig. 7.41 - Toughness Index I5 -lst-CR vs. Time for Different Mixes, (Vf-l%) ............ 110
Fig. 7.42 - Toughness Index I5 -co vs. Time for Different Mixes, (Vf=2%) .................. 112
Fig. 8.1 - Flowchart of the Splitting Tensile Experimental Program .............................. 121
Fig. 8.2 - Specimen I19Code ........................................................................................... 122
Fig. 8.3 - Set-up for Splitting Tensile Test ..................................................................... 123
Fig. 8.4 - Specimen Positioning for the Splitting Tensile Test ....................................... 124
Fig. 8.5 - Modulus of Rupture fr vs. ",1f'c'for Different Mixes ...................................... 128
Fig. 8.6 - Splitting Tensile Strength fspt vs. _/f'c'for Different Mixes .......................... 128
Fig. 8.7 - Splitting Tensile Strength fspt for Different Mixes, 1Day, (Vf=l%) .............. 129
Fig. 8.8 - Splitting Tensile Strength fspt for Different Mixes, IDay, (Vf--2%) .............. 129
Fig. 8.9 - Splitting Tensile Strength fspt for Different Mixes, 1Day,
Latex, (Vf=1%) ............................................................................................... 131
Fig. 8.10 - Splitting Tensile Strength fspt for Different Mixes, 1Day,
Silica Fume, (Vf=1%) ................................................................................... 131
Fig. 8.11 - Compressive Strength f'c for Different Mixes, 1Day, (Vf=l%) ................... 132
Fig. 8.12 - Compressive Strength f'c for Different Mixes, 1Day, (Vf=2%) ................... 132
Fig. 8.13 - Compressive Strength f'c for Different Mixes, 1Day, Latex, (Vf=l%) ........ 133
Fig. 8.14 - Compressive Strength f'c for Different Mixes, 1Day,
Silica Fume, (Vf=l%) ................................................................................... 133
Fig. 9.1 - Experimental Program for Flexural Fatigue .................................................... 138
Fig. 9.2 - Testing Machine Used in Flexural Fatigue Tests ............................................ 140
Fig. 9.3 - Instrumentation and Test Set-Up for Flexural Fatigue Tests ......................... 141
Fig. 9.4 - Specimen #10 after Fatigue Failure, Mix A2%S3,
Load Range 10%-70% .................................................................................... 144
Fig. 9.5 - Specimen #15 after Fatigue Failure, Mix A2%S3S5,
Load Range 10%-90% .................................................................................... 144
Fig. 9.6 - Modulus of Rupture versus Dynamic Modulus .............................................. 148
xiii
Fig. 9.7 - Number of Cycles to Failure versus Maximum Applied Load ....................... 148
Fig. 9.8 - Load versus Deflection Hysteretic Response of Specimen #16
under Fatigue Loading .................................................................................... 150
Fig. 9.9 - Load versus Deflection Hysteretic Response of Specimen #20
under Fatigue Loading .................................................................................... 150
Fig. 9.10 - Load versus Deflection Hysteretic Response of Specimen #18
under Fatigue Loading .................................................................................. 152
Fig. 9.11 - Variation of Deflection versus Number of Cycles for Specimen #21 ........... 152
Fig. 9.12 - Variation of Deflection versus Number of Cycles for Specimen #18 ........... 153
Fig. 9.13 - Variation of Deflection versus Number of Cycles for Specimen #17 ........... 153
Fig. 9.14 - Load versus Deflection Response after Fatigue: Loading
for Specimen #17 .......................................................................................... 154
Fig. 9.15 - Variation of Strain versus Number of Cycles for Specimen #21 .................. 154
Fig. 9.16 - Variation of Strain versus Number of Cycles fi_rSpecimen #10 .................. 155
Fig. A.1 - A.79: Stress versus Strain Curves for each Series and its Representative
Average Curve ............................................................................. 188
Fig. A.80 - A.94: Stress versus Strain Response with Time and Effect of Cylindrical
Size .............................................................................................. 228
Fig. A.95 - A.104: Stress versus Strain response for Different Series ........................ 236
Fig. A.105 - A. I I 1: Compressive Strength f'c ............................................................. 241
Fig. A.112 - A.120: Elastic Modulus ............................................................................ 245
Fig. B. 1 - B. 16: Graphs of Load versus Deflection and Strain Capacity
Response with Time ..................................................................... 257
Fig. B.17 - B.20: Load versus Deflection Response for Different Series ................. 265
Fig. B.21 - B.29: Modulus of Rupture fr .................................................................. 267
Fig. B.30 - B.39: Toughness Indices ........................................................................ 272
Fig. C.1 - C.7 • Load versus Deflection Hysteretic Kesponse under
Fatigue Loading ............................................................................ 278
xiv
Fig. C.8 - C12 : Variation of Deflection versus Number of Cycles ....................... 282
Fig. C. 13 : Load versus Deflection Response after Fatigue Loading ............. 284
Fig. C. 14 - CI 8: Variation of Strain versus Number of Cycles ............................... 285
Fig. C. 19 - C20: Load versus Strain Response after Fatigue Loading .................... 288
Fig. C.21 - C30: Load versus Strain Response under Static Loading ..................... 289
Fig. C.31 - C38: Load versus Strain Response under Static Loading ..................... 294
List of Tables
Table 1.1 - Criteria for HPC ................................................................................................ 9
Table 3.1 - Aggregate Gradation for the Coarse Aggregates (Gravel) .............................. 20
Table 3.2 -Aggregate Gradation for the Fine Aggregates (Sand) ..................................... 20
Table 3.3 - Properties of Fibers Used ................................................................................ 20
Table 4.1 -Design Proportions for Mix Series A, B, and C ......................................... 27
Table 4.2 - Matrix Composition for Mix Series A, B, and C
(Proportions are given by weight) .................................................................. 28
Table 4.3 - Typical Fiber Content by Weight as Used in This Study ................................ 28
Table 5.1 - HESFRC Plastic Properties ............................................................................. 33
Table 6.1 - Number of Specimens Tested ......................................................................... 38
Table 6.2 - Summary of the Average Values of f'c and Ec
Obtained for Each Time Series .................................................................... 44
Table 7.1 - Number of Specimens Tested ......................................................................... 76
Table 7.2 - Summary of Main Flexural Test Results ........................................................ 85
Table 8.1 - Number of Specimens Tested ....................................................................... 120
Table 8.2 - Average f'c, fr, and fspt Values for Each Time Series ................................ 126
Table 9.1 - Results of Dynamic Modulus and Modulus of Rupture Tests ...................... 142
Table 9.2 - Results of Fatigue Tests ................................................................................ 145
Table A. 1 - A. 16: Tables of Values of f'c and Ec for Each Specimen and Average
Values and Standard Deviation of Each Series ............................. 172
Table B.1 - Strength Results for Each Individual Specimen ............................................ 252
xvii
Preface
The Strategic Highway Research Program (SI-IRP)is 5-year nationally coordinated research
effort initiated in 1988 at a cost of $150 million. This highly focused and mission-oriented
program originated from a thorough and probing study* of deterioration of the nation's
highway and bridge infrastructure. The study documented the need for a concerted research
effort to produce major innovations for increasing the productivity and safety of the nation's
highway system; further, it recommended that the research effort be focused on six critical
areas in which the nation spends most of the $50 billion used for roads each year, and thus
technical innovations would have the potential for substantial payoffs. The six critical research
areas were as follows:
• Asphalt Characteristics
• Long-Term Pavement Performance• Maintenance Cost Effectiveness
• Concrete Bridge Component Protection
• Cement and Concrete
° Snow and Ice Control
When SHRP was implemented, the two research areas of Concrete Bridge Component
Protection and Cement and Concrete were combined under a single program directorate of
Concrete and Structures. Likewise, the two research areas of Maintenance Cost-Effectiveness
and Snow and Ice Control were also combined under another program directorate of Highway
Operations.
*America's Highways: Accelerating the Search for hmovatio,s. Special Report 202, Tr,'mspormtion Rese,'u'chBorn-d, Nation,,d Rese,'u'ch Council, Washington. DC 1984.
xix
Abstract
This study provides an extensive databasc and a summary of a comprehensive experimental
investigation on the fresh state and mechanical properties of high early strength fiber reinforced
concrete(HESFRC).The controlhighearlystrength(HES)concreteusedforfiberaddition
andtheresultingHESFRC arcdefinedasachievingatargetminimum compressivestrengthof
5ksi(35MPa) in24hours,asmeasuredfrom4x 8-in.(100x 200-ram)cylinders.Fresh
HESFRC propertiestestedincludeaircontent,workability(bytheinvcrtcdslumptest),
temperature,andplasticunitweight.Testsonthemechanicalpropertiesincludecompressive
strength,elasticmodulus,flcxuralstrength,splittingtensilestrength,andfatiguelife.Sixteen
differentcombinationsofparameterswereinvestigated;thevariableswerethevolumefraction
offibers(1% and2%),thetypeoffiber(steel,polypropylene),thefiberlengthoraspectratio,
andtheadditionoflatexorsilicafumetothemix.Optimalmixesthatsatisfiedtheminimum
compressivestrengthcriterion,andshowedcxceUcntvaluesof modulusofrupture,toughness
indicesinbending,andfatiguelifeinthecrackedstate,arcidentified.Potentialapplicationsin
construction,repair,andrehabilitationoftransportationstructuresaresuggested.
Executive Summary
The main objectives of this experimental study were (I) to establish a consistent and
comprehensive database on high early strength fiber reinforced concrete (HESFRC), (2) to
document and synthesize information on the properties of the fresh mix and the mechanical
properties of the hardened composite, and (3) to develop some practical recommendations for
use of HESFRC by the profession. It should be noted that although several thousand
investigations have dealt with fiber reinforced concrete, none has included such a complete
range of tests (from the fresh state to the hardened composite) and tested such a range of
parameters as this study, and none has provided the same consistent testing procedures
throughout. This experimental investigation followed an initial evaluation of existing
knowledge in the field as summarized in an earlier state-of-the-art report and an annotated
bibliography on high performance fiber reinforced concrete.
HESFRC was dcf'med as achieving a minimum target compressive strength of 5 ksi (35 MPa)
in 24 hours. Since the minimum strength criterion could be satisfied by the control specimens
without fibers, and since in current applications of fiber rcinforced concrete for pavements only
low fiber contents (0.10% to I% by volume of concrete) are used, it was decided to explore
and documcnt a higher range of fiber content (1% and 2% by volume of concrete). The main
intent was to achieve, in addition to the minimum specified compressive strength, a post-
cracking strength in bending (i.e., a modulus of rupture) higher than the cracking strength so
as to minimize crack widths and ensure a sufficient resistance to repeated loads after cracking.
Several properties of HESFRC were investigated, including, for the fresh mix, the air content,
workability (by the inverted slump test), temperature, and unit weight and, for the hardened
composite, the compressive, bending, tensile, and fatigue properties. Particular attention was
given to recording not only key properties such as compressive strength, elastic modulus, and
modulus of rupture, but also the entire stress-strain response in compression and load-
deflection curve in bending so as to provide additional information on strain capacity and
complete data for future reference. Also, values of toughness indices at different deflections
were calculated from the load-deflection curves.
Sixteen different combinations of parameters were investigated for each type of test. Moreover,
for the bending tests only, one additional mix containing 0.15% by volume of polypropylene
fibers was also tested (at the request of the project Expert Task Group) to simulate current low-
fiber- content mixes used in some applications, such as slabs on grade.
The main parameters included (1) three different matrix mixes (one control, one with silica
fume, and one with latex), (2) two different volume fraction of fibers (1% and 2%), (3) two
fiber materials (steel and polypropylene), 114)two steel fiber lengths corresponding to aspect
ratios of 60 and 100 respectively, and (5) hybrid mixes containing either an equal amount of
steel and polypropylene fibers or an equal amount of steel fibers of different lengths. The
compression and the bending tests also included a time variable; the compressive properties
were measured at ages 1, 3, 7, and 28 days, and the bending properties at ages 1, 7, and 28
days, respectively. Information from the compression tests comprised the compressive
strength, the elastic modulus, and the strain capacity. Also, the effect of specimen size, i.e.,
4 x 8-in. (100 x 200-mm) cylinders versus 6 x 12-in. (150 x300-mm) cylinders, was
documented. Information from the bending tests included the modulus of rupture and the
toughness indices as per ASTM standards.
The main conclusions are as follows.
OveraLl, the additions of 2% by volume of 30/50 hooked steel fibers (or 2% of an equal
combination of 30/50 and 50/50) gave optimal composite properties in the fresh and hardened
state. It caused significant increases in the compressive strength, modulus of rupture, splitting
tensile strength, toughness indices, ductility (or strain capacity), and fatigue limit when
compared with all other HESFRC mixes, as well as with the control mix without fibers. In
comparison with the control mix, average increases of 30% in compressive strength, 270% in
modulus of rupture, 250% in splitting tensile strength, and predicted endurance limit in
bending of 65% of ultimate while in the cracked state were observed. Moreover, values of
toughness indices 15 and I10 as high as 30 and 60 imply energy absorption capacities at least30 to 60 times that of the control mix without fibers.
Next in performance were the mixes containing 1% by volume: of 50/50 or 30/50 + 50/50
hooked steel fibers; both mixes performed similarly in terms of compressive strength, elastic
modulus, modulus of rupture, and splitting tensile strength. In comparison with the control
mix without fibers, these mixes led to little change in compressive strength, but, on average,
increased the modulus of rupture and splitting tensile strength by 200% and 173%
respectively. Here toughness indices as high as 9 for 15 and 23 for I10 were observed.
In general, the property affected most by the addition of fibers, be it steel or polypropylene
fibers, is the toughness index in bending. Toughness indices 15 and I10 generally exceeded 5
and 10, respectively, when 1% fibers by volume was added. Thus, a substantially improved
energy absorption capacity (which can be translated in improved impact energy) seems to be
the most evident benefit of adding fibers to HES concretes.
Mixes containing 1% or 2% by volume of polypropylene (PP) fibers showed deterioration in
the compressive stress-strain response when compared with the control mix. The mix with 2%
by volume of PP fibers was more difficult to mix, led to larger a volume of entrapped air, and
resulted in poorer properties than the mix with 1% PP fibers by volume. Therefore, the use of
polypropylene fibers only to improve compressive strength and elastic modulus is not
recommended. However, as mentioned above, polypropylene fibers did markedly improve
the toughness index of the composite.
Although latex improved the workability of HESFRC mixes and their 28-day compressive
strength, its use is not desirable for the sole purpose of improving early age properties.
However, it should be observed that latex is generally used to improve the bond between new
and old concrete in repair applications, and is known to improve durability. These very
important properties were not tested in this investigation.
The addition of silica fume does not significantly affect the 1-day compression, bending, and
tensile properties of HESFRC composites. However, properties at later ages were improved
similarly to those of plain concrete.
Hybrid mixes with steel andpolypropylene fibers did not fare as well as all-steel fiber mixes
with the same total fiber content by volume.
The compressive strength of HESFRC mixes obtained from 6 x 12-in. (150 x 300-mm)
cylinders was, on average, 3.9% smaller than that obtained from 4 x 8-in. (100 x 200-mm)
cylinders.
Given the properties observed in this investigation, it can be inferred that high early strength
fiber reinforced concret* (HESFRC) containing fibers (pardc_arly hooked steel fibers) in 1%
to 2% by volume, can be used for several highway-related applications. They include, (1)
repair type applications for which early strength and toughness (energy absorption and impact
properties) are needed, such as for potholes, bridge decks, overlays, pavement joints, piers,
and runways; and (2) applications in new structures, particularly bridge decks, pavements,
bridge piers, piles, reusable median barriers, taxiways, and runways. These are applications
for which the specific advantages of HESFRC compared with HES concrete without fibers are
needed such as its increased resistance to cracking, its increased toughness (i.e., energy
absorption capacity against dynamic and impact Ioadings and resistance to damage), its
increased ductility, its smaller crack widths (thus reducing penetration of chlorides), and its
increased fatigue. Moreover, HESFRC can be used in conventional reinforced and
pres_essed concrete structures to replace the plain concrete matrix. In such cases, the use of
HESFRC is expected to lead to substantially improved structural ductility, better hysteretic
response under cyclic load reversals, better bonding of the reinforcing bars, improved
resistance of the concrete cover to spaUing, improved shear resistance, savings in stirrups, and
overall improved energy absorption capacity of the structure.
6
1
Introduction
1.1 SHRP C-205: Mechanical Behavior of High PerformanceConcretes
1.1.1 Project Overview
One of the eleven projects in the program areaof Concrete and Structures is SHRP C-205
entitled "Mechanical Behavior of High Performance Concretes", which is a 4-year study
initiated on March 1, 1989. There were three generalobjectives of the project:
(1) To obtain needed information to fill gaps in the present knowledge;
(2) To develop new, significantly improved engineering criteria for the mechanical
properties and behavior of high performance concretes; and
(3) To provide recommendations and guidelines for using these concretes in highway
applications according to the intended use, required properties, environment, and
service.
Both plain and fiber reinforced concretes were included in the study. The research f'mdings axe
presented in a series of project reports in six separate volumes, Mechanical Properties of High
Performance Concretes, as follows:
Volume 1 Summary Report
Volume 2 Production of High Performance Concrete
Volume 3 Very Early Strength (VES) Concrete
Volume 4 High Early Strength (HES) Concrete
Volume 5 Very High Strength (VHS) Concrete
Volume 6 High Early Strength Fiber Reinforced Concrete(HESFRC)
The discussion of the development and production of high early strength fiber reinforced
concrete (HESFRC) is covered in this report (Volume 6), and a brief summary for field mixing
and handling is provided in the overall summary report (Volume 1).
1.1.2 Definition of High Performance Concrete (HPC)
In general terms, high performance concrete (HPC) may be defined as any concrete that
provides enhanced performance characteristics for a given application. Concretes that provide
substantially improved resistance to environmental influences, high durability under service
conditions, extraordinary properties at early ages, or substantially enhanced mechanical
properties, are potential HPCs. These concretes may contain materials such as fly ash, ground
granulated slags, silica fume, fibers, chemical admixtures, and other materials, individually or
in various combinations [3,4].
Engineers are making increasing use of HPCs for a variety of highway applications, including
new construction, repairs, and rehabilitation. Higher-strength concrete can make possible more
structural design flexibility and provide more options. Improved early age properties of
concrete can facilitate construction and rehabilitation tasks and improve qnality. Higher
durability can increase the service life, which may reduce life cycle cost.
For the purpose of this research program, HPC is defined in terms of certain target strength
and durability criteria as specified in Table i.1. Additional target criteria for high early strength
fiber reinforced concrete (HESFRC) are explained in the next .section.
In this definition, the target minimum strength should be achieved in the specified time after
water is added to the concrete mixture. The water/cement ratio (W/C) is based on all
cementitious materials. The minimum durability factor should be achieved after 300 cycles of
freezing and thawing according to ASTM C 666 (procedure A) [i].
Table 1.1 - Criteria for HPC
Category of HPC Minimum Maximum Minimum FrostCompressive Water/Cement DurabilityStrength Ratio Factor
Very Early Strength (VES)
Option A 2,000 psi (14 MPa) 0.40 80%(with Type III cement) in 6 hours
Option B 2,500 psi (17.5 MPa) 0.29 80%(with Pyrament, PBC-XT in 4 hourscement)
High Early Strength 5,000 psi (35 MPa) 0.35 80%(HES) in 24 hours
(with Type III cement)
Very High Strength 10,000 psi (70 MPa) 0.35 80%(VHS) in 28 days
(with Type HI cement)
These working definitions of HPC were adopted after several important factors were
considered with respect to the construction and design of highway pavements and structures.
The rationale for the selection of the various limits can be found in the project summary report
(Volume 1).
The strength criterion for very early strength (VES) concrete was originaUy defined by the
researchers of this project as that of option B, with no particular reference to the type of cement
(special cement if needed) to be used. However, in the interest of establishing an alternative
with portland cement as the binding material, the strength criterion of option A was adopted
with the recommendation of the Expert Task Group of the project.
1.2 High Early Strength Fiber Reinforced Concrete (HESFRC)
1.2.1 Summary
This report, volume 6 of the SHRP C-205 series of reports, presents the results of an extensive
experimental investigation on the properties of high early strength fiber reinforced concrete
(HESFRC) in both the fresh and hardened states. Like high early strength (HES) concrete,
HESFRC was defined as achieving a minimum target compressive strength of 5 ksi (35 MPa)
in 24 hours. Since the minimum-strength cliterion could be satisfied with the control specimens
without fibers, and since in current applications of fiber reinforced concrete for pavements only
low fiber contents (0.10% to 1% by volume of concrete) are used, it was decided to explore
and document a higher range of fiber content (1% and 2% by volume of concrete). The main
intent was to achieve, in addition to the minimum specified target compressive strength, a
postcracking strength in bending (i.e. a modulus of rupture) higher than the cracking strength
so as to minimize crack widths and insure a sufficient resistance to repeated loads after
cracking. This implied a minimum ductility behavior in bending otherwise not present in the
control specimens without fibers.
It should be noted that although several thousand investigations have dealt with fiber reinforced
concrete, none has included such a range of tests (from the fresh state to the hardened composite)
and tested such a range of parameters as in this study, and none has provided the same consistent
testing procedures throughout. This experimental investigation followed an initial evaluation of
existing knowledge in the field, as summarized in an earlier state-of-the-art report [3] and an
annotated bibliography on high performance fiber reinforced concrete (see Bibliography).
The fresh HESFRC properties measured included air content, workability (by the inverted
slump test), temperature, and plastic unit weight. Tests on the properties of the hardened
material included compressive strength, flexural strength, splitting tensile strength, and fatigue
life. In all 16 different mixes were investigated in depth; the variables included the volume
fraction of fibers, the type of fiber material, the fiber length, hybrid fiber composition, and theuse of silica fume or latex additives.
10
1.2.2 Organization of This Report
This report follows the same format used in the other volumes in this series. Chapters 2 to 5
describe the objectives and scope of this study, the characterization of the constituent materials
used, the mixture proportions, and the mixing and curing procedures, respectively.
Chapter 6 presents the properties of fresh HESFRC and the corresponding compressive
strength andelastic modulus with time. The effects of latex and silica fume on the compressive
stress-strain response and elastic modulus were also investigated and compared to plain
HESFRC. Two fiber types were used: hooked steel fibers and polypropylene fibers. For the
hooked steel fibers, two aspect ratios were examined corresponding to 30/50 fibers (i.e., 30
mm long and 0.5 mm in diameter) and 50/50 fibers (50 mm long and 0.5 mm in diameter).
Several combinations of both fiber types were examined using 1% and 2% by volume of the
concrete mix. The effects of latex and silica fume were also investigated and compared to plain
HESFRC. Test results include the overall stress-strain relationship, the compressive strength,
and the elastic modulus, all measured at.l, 3, 7, and 28 days. In all, more than 220 specimenswere tested.
Chapter 7 focuses on bending properties, namely the load versus deflection and load versus
strain capacity response in flexure. The strain was measured over a 4-in. gauge length along
the constant moment region on the tensile face of the beam tested. The same set of parameters
used for the compression tests was also selected for the bending tests. Test results include the
overall load versus deflection and load versus strain capacity relationships with time (measured
at 1, 7, and 28 days), the flexural strength with time, and the toughness indices, I5, I10, and
I20. The toughness indices were measured using two procedures, the ASTM C 1018 [2]
procedure, in which the reference deflection is taken as the deflection at cracking of the same
specimen under test, and a more accurate procedure in which the reference deflection is taken
as that of the control specimen without fibers.
Chapter 8 focuses on the tensile properties of HESFRC composites as obtained from the 1-day
splitting tensile strength. The splittting tensile strength is also compared with the modulus of
rupture (i.e., the tensile strength obtained from the bending tests) and compressive strength of
the same mixes. The same parameters used for the compression and bending tests wereinvestigated.
11
Chapter 9 focuses on the structural perfornmnce of HESFRC under flexural fatigue loading.
The test program was designed to provide data on the stiffness degradation, cracking
characteristics, and number of cycles to failure of HESFRC specimens subjected to flexural
fatigue loading. The parameters investigated were the stress range and the type of fibers used.
The specimens were subjected to three stress ranges, corresponding to 10% to 70%, 10% to
80%, and 10% to 90% of the static flexural strength obtained from sister specimens. The types
of fiber used were the 30/50 steel fibers and 50/50 steel fibers (see description above). Two
combinations of fibers were tested, with 2% fibers by volume of concrete. One set of
specimens was reinforced with 30/50 fibers, and another set was reinforced with an equal
combination of 30/50 and 50/50 fibers. No hybrid mix of steel and polypropylene fibers was
tested in fatigue, because the properties of such a mix in both static compression and bending
were not as good as those of the mixes reinforced with all steel fibers. The test results are
presented as plots of the load versus deflection and load versus tensile strain (in bending) for
different numbers of cycles. The fatigue life for the different load ranges is illustrated in a plot
of the maximum load level versus the number of cycles to failure (S-N diagram).
Finally, Chapter 10 provides an overall summary of the conclusions and recommendations
drawn from this investigation.
12
1.3 References
1. ASTM Standards. Test Method for Resistance of concrete to Rapid Freezing andThawing. ASTM C 666-90. Vol. 04.02. 1991.
2. ASTM Standards. Test Method for Flexural Toughness and First-Crack Strength ofFiber-Reinforced Concrete (Using Beam with Tbdrd-Point Loading). ASTM C 1018-89. Vol. 04.02. 1991.
3. Naaman, A.E., and M.H. Harajli. Mechanical Properties of High Performance FiberConcretes: A State-of-the-Art Report. Report no. SHRP-C/WP-90-004, SHRP,National Research Council, Washington, D.C. 1990.
4. Zia, P., M.L. Lemming,and S.H. Ahmad. High Performance Concretes: A State-of-the-Art Report.. Report no. SHRP-C-317. SHRP, National Research Council,Washington, D.C. 1991.
13
2
Objectives and Scope
The main objectives of this investigation were (1) to establish a consistent and comprehensive
database on the properties of high early strength fiber reinforced concrete (HESFRC), (2) to
document and synthesize information on the properties of the fresh mix and the mechanical
properties of the hardened composite, and (3) to develop some practical recommendations for
use of HESFRC by the profession.
High early strength (lIES) concrete, as defined in Section 1.1., when reinforced with fibers,
can be used for several highway related applications. They include (1) repair-type applications
for which early strength properties are needed such as for potholes, bridge decks, overlays,
pavement joints, and runways; and (2) applications in new structures particularly bridge decks,
pavements, median barriers, taxiways and runways. These are applications in which the
specific advantages of HESFRC compared with HES concrete without fibers are needed, such
as its increased resistance to cracking, its increased toughness (i.e., energy absorption capacity
against dynamic and impact loadings), its increased ductility, and its increased fatigue life.
Moreover, HESFRC can be used in reinforced and prestressed concrete structures to replace
the plain concrete matrix in these structures. In such cases, its use is expected to lead to
substantially improved structural ductility, better hysteretic response under cyclic load
reversals, better bonding of the reinforcing bars and prestressing tendons, improved resistance
of the concrete cover to spalling, smaller crack widths, and overall improved energy absorption
capacity of the structure.
The experimental investigation included several parts dealing with the properties of HESFRC:
the properties of the fresh mix (air content, workability by the inverted slump test, temperature,
15
and unit weight), and the compressive,bending, tensile, and fatigue propertiesof the hardened
composite. Only HESFRC is considered hc_'eand was defined as achieving a minimum target
compressive strength of 5 ksi (35 MPa) in 24 hours (see also section I. 1).
In relation to the part of the experimentalprogram dealing with the compression tests (chapter
6), the main objective was to study how using different types of fibers affected the plastic
properties of fresh fiber reinforced concrete,and the compressive properties of the hardened
fiber concrete composite. The following three major goals were sought: (1) to measure the
fresh properties of various HESFRC mixes, which include plastic unit weight, temperature,
workability (using the inverted cone test), and air content; 2) to obtain the complete
experimental stress-strain curves of various I-IESFRCmixes tested at 24 hours (1 day), and
then compare the results to tests performed at 3, 7, and 28 days; and (3) to determine the values
of strengthand modulus of elasticity of the composite and their variation with time between 1
day and 28 days.
The main objectivesof the bending tests (chapter7) were to investigatethe effects of using
different types of fibers in various amounts on the flexural properties of HESFRC, and to
determine which mix gives best values of modulus of rupture and/or toughness index. The
following major tasks were undertaken: (1) study the load versus deflection and load versus
straincapacity relationships at 1 day, and thencompare the results to similar tests performed at
7 and 28 days; (2) calculate the modulus of rapture of the hardened composite; and (3)
calculate the toughness indices of all mixes at different ages (1, 7, and 28 days), using for
reference (a) the area under the loadversus deflectioncurve up to first cracking of the
composite, as recommended by ASTM C 1018, and Co)the area under the load versusdeflection curve of the nonreinforced control mix.
The main objectiveof the part of this investigationdealingwith the splitting tensile tests
(chapter 8) was to investigate the splitting tensile strength,fspt, and corresponding compressive
strength,re, of all HESFRC mixes at 1 day. The results were also compared with the modulus
of rupture obtained from the bending tests (chapter7).
In chapter9, the overallobjectivewas to investigatethe behaviorof HESFRCunder flexural
fatigue loading, subjectedto differentstressranges andreinforcedwith two differentfiber
combinations. Thefibercombinationswere selected to correspondto mixes that gave best
compression,bending,and splitting-tensilepropertiesin the static tests. The maintasks can be
summarizedas follows: (1) to study the progressivestiffnessdegradationand cracking
behaviorof the HESFRC specimens byanalyzing their load versusdeflection and load versus
16
tensile strain curves; and (2) to obtainsome experimentaldata on the fatigue life of HESFRC
mixes under different stress ranges. The stress ranges tested corresponded to a load fluctuation
between a minimum of 10%of the flexural ultimate load, and a maximum of either 70%,80%
or 90%,respectively.
17
3
Characterization of Constituent Materials
3.1 Cement
Type HI high early strength cement was used. Cement was obtained from two different
suppliers: St. Marys Peerless Cement Company and Huron Cement Company, both in
Michigan. Type 1TIcement was needed to achieve the high early strength properties at 24
hours, as set by the criteria described in section 1.1.
3.2 Coarse Aggregates
The coarse aggregate used crushed limestone with a maximum size of 0.5 to 0.75 in. It was
purchased from Washtenaw Sand and Gravel Company in Ann Arbor, Michigan. The reason
for selecting a relatively small-size aggregate is to improve the efficiency of fiber
reinforcement. In steel-fiber-reinforced concrete practice, it is generally recommended that the
length of the fiber be at least twice the maximum size of the aggregate. In this study, steel fiber
lengths used were 30 mm (1.2 in.) and 50 mm (2 in.). The gradation results for the coarse
aggregate, as obtained from tests undertaken in the laboratories according to ASTM C 33, are
given in Table 3.1.
19
Table 3.1. Aggregate Gradation , Coarse Aggregates (Gravel)
Sieve Actual Percentage Cumulative CumulativeSize Weight of Weight Percentage Percentage
Retained (g) Retained Retained Passing1 in. 0 0 0 100
3/4 in. 85 9 9 911/2 in. 410 41 50 503/8 in. 160 16 66 34
#4 235 24 90 10#8 0 0 90 10
Pan 110 11 100 0
Table 3.2. Aggregate Gradation , Fine Aggregates (Sand)
Sieve Actual Percentage Cumulative CumulativeSize Weight of Weight Percentage Percentage
Retained (g) Retained Retained Passing#4 0 0 0 100#8 45 9 9 91
#16 75 15 24 76#30 70 14 38 62#50 130 26 64 36
#100 150 30 94 6#200 25 5 99 1Pan 5 1 100 0
Table 3.3. Properties of Fibers Used
Fiber Fiber Length Diameter Aspect Density SpecificName Material (mm) (mm) Ratio(l/d) (pcf) Gravity30/50 Steel 30 0.5 60 490 7.8550/50 Steel 50 0.5 100 490 7.85
PP Poly- 12.7 0.095 133.6 56.8 0.91propylene 19 Mo.,,_.,._.t 200
Note: Aspect ratio is length divided by diameter.
2O
3.3 Fine Aggregates
A graded sand, identified as type 2-NS and supplied for general concrete by Washtenaw Sand
and Gravel Company in Ann Arbor, Michigan, was used. The gradation results for the sand,
as obtained from tests undertaken in the laboratories according to ASTM C 33, are given inTable 3.2.
3.4 Mineral Admixtures
Silica fume was supplied as an emulsion by Elkem Materials Inc., Pittsburgh, Pennsylvania;
the amount of water contained in the emulsion was assumed to be 50%, as suggested by the
supplier. The amount of water contained in the emulsion and the amount of microsilica were
accounted for in computing the ratio of water to cementitious material in the mix.
3.5 Chemical Admixtures
Air-entraining agent (AEA; Vinsol resin), Darex Corrosion Inhibitor (DCI), and
superplasticizer (Melmen0 were also used. The amount of water contained in the DCI solution
(70% water) was also considered in determining the water content of the mix.
3.6 Other Admixtures
Latex emulsion, supplied by Dow Chemical, Midland, Michigan, was utilized in test series B
only. It was assumed that the latex emulsion contained 60% water, as suggested by the
supplier.
3.7 Fibers
Steel and polypropylene fibers were used in this investigation. The properties of these fibers
are summarized in Table 3.3. Information on strength and modulus of the steel fibers was
obtained from the supplier. No such information was available for the polypropylene fibers. It
should be observed that, since most fibers pull out rather than break, during the failure of fiber
21
reinforced concrete specimens, the tensile strength of the fibers is not as important as their
bond properties.
22
4
Mixture Proportions
4.1 Development Phase
Several mixes described in volumes 2 and 4 of this series of reports were tried with fibers,
particularly 1% and 2% by volume of 30/50 hooked steel fibers; however, either the fibers
could not be mixed properly or the target one day compressive strength of 5 ksi (35 MPa) was
not attained. The final HESFRC mixes selected for this investigation and described in this
chapter contain a lesser proportion of course aggregates, with smaller maximum size, than theHES mixes without fibers described in volume 4.
4.2 Production Phase
The f'mal mixes were divided in three series, A, B, and C, and a control mix. Series A
consisted of HESFRC mixes having two volume fractions (1% and 2% by volume of concrete)
and two types of fiber (hooked steel fibers having two aspect ratios and one type of
polypropylene fibers). Series B consisted of HESFRC mixes plus latex with one volume
fraction of fibers (Vf = 1%).Series C consisted of HESFRC mixes plus microsilica (silica
fume) also with one volume fraction (Vf = 1%). A flowchart showing the different series is
presented in Fig. 4.1.
The water/cement (W/C) ratio for series A was kept at 0.34. In designing the mixes of series
B, it was assumed that the latex emulsion contained 60% water, as suggested by the supplier.
Several trial mixes were tried but achieved a 1-day compressive strength less than 5 ksi.
Finally, to achieve the required 1 day strength of 5 ksi, it was decided to reduce the W/C ratio
of mix series B from 0.34 to 0.30 while maintaining the minimum desired workability of the
mix which was measured by the inverted cone test as described in Section 5.3.
23
-t_ _ R_u_
•o --1_o
N _
L -I-I °t_
.._
24
Series C, whichcontainedsilica fume, had a ratioof waterto cementitiousmaterial (i.e.,
cement plus solid microsilica)of 0.32. Since silica fume was supplied as anemulsion, theamountof watercontainedin the emulsion was assumed to be 50%, as suggested by the
supplier.The amount of water containedin the emulsion andthe amountof microsilica were
accountedforin computing the water/cementitiousratio.
The amountof water containedin the DCI solution (70% water) was also considered in
determining the watercontent of the mix.
Table 4.1 shows the mix proportions used to design mix series A, B, and C, and Fig. 4.2
describes the mix ID code used throughout this study; information on specimen ID code is
given at the beginning of each chapter for the specific type of test undertaken. In Table 4.1, all
values givenin parenthesesrepresent theratio of the weight of the component material to the
weight of cement, and the first value in each cell represents the weight of material used in
pounds per cubic yard (pcy). Table 4.2 summarizes the mix proportions in terms of ratio of
weight of component to weightof cement, and Table 4.3 gives the equivalent weight of fibersfor the various fiber volume fractions used.
Besides the adjustments made to the total W/C ratio, Table 4.1 shows two other adjustments
made to the cementcontent. The cementwas purchased from two different suppliers. Mix
series A were all designed using Type 1IIcement obtained from the first supplier.The Type 111
cement used for series B mixes was purchased from a different supplier. It was then observed
that the compressivestrengthat 1day decreased significantly.Tobalance the reduction in
strength, the cementcontent of mix series B was increased from 850 to 900 lacy.
As shown in Fig. 4.1, two of the mixes of series A, called hybrid mixes, contained either two
different fiber lengths or two differentfiber materials.It was anticipated that a hybrid mix
might have some advantages;for exmaple, one fiber might contribute to higher strength and the
other to increased toughness or ductility.
The steel fibers used in this investigationwere the Dramix 30/50 and 50/50 hooked steel fibers,
to be designated from now on as 30/50 and 50/50, respectively. The diameter of the 30/50 and
50/50 fibers is 0.5 mm, and their length is, respectively 30 mm and 50 mm, leading to aspect
ratios of 60 and 100,respectively. As shown in Fig. 4.1, two volume fractions of fibers (1%
and 2%) were investigatedfor all mixes of series A, except for the mix containing 50/50 fibers,
for which only 1% fibers by volume was used because it was not possible to properly mix 2%
50/50 fibers by volume with the desired W/C ratio.
25
A 1% $3S5
Type of Fibers Used in the Mix:
• $3 = 30/50 Hooked Steel Fibers• $5 = 50/50 Hooked Steel Fibers• P0.5 = 0.5 in. Polypropylene Fibers• P0.75 = 0.75 in. Polypropylene Fibers• $3S5 = 30/50 + 50/50 (Hybrid mix)• $3P0.5 = 30/50 Hooked Steel + 0.5 in.
Polypropylene Fibers
Fiber Volume Fraction
Mix Series A, B, or C
Fig. 4.2 - Mix ID ('ode
26
Table 4.1. Design Proportions for Mix Series A, B, and C
Mix ID Ad. C W Total S CA Mel. AEA DCI Ad.
Type (pcy) (pcy) w/c (pcy) (pcy) (pcy) (pcy) (pcy) (pcy)Control -- 850 235 0.34 1250 1550 29.75 4.25 78.5
(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)A1%S3 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --
(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)A2%S3 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --
(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)A1%S5 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --
(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)AI%P0.75 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --
(I) (0.28) (1.47) (1.82) (3.5%) ((3.5%) (9.2%)A2%P0.75 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 m
(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)A1%S3S5 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --
(1) (0.28) (1.47) (I .82) (3.5 %) (0.5 %) (9.2%)A2%S3S5 -- 850 235 0.34 1250 1550 29.75 4.25 78.5
(I) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)
AI%S3P0.5 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 ---(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)
A2%S3P0.5 -- 850 235 0.34 1250 1550 29.75 4.25 78.5 --(1) (0.28) (1.47) (1.82) (3.5%) (0.5%) (9.2%)
B 1%S5 Latex 900 98 .30 1250 1550 31.5 2.7 90 190(1) (0.11) (1.47) (1.82) (3.5%) (0.3%) (9.2%) (0_,1)
Bl%P0.5 Latex 900 98 .30 1250 1550 31.5 2.7 90 190(1) (OdD (1.47) (1.82) (3.5%) (0.3%) (9.2%) (091)
B0%Con Latex 900 98 .30 1250 1550 31.5 2.7 90 190(1) (0.1 I) (1.47) (1.82) (3.5%) (0.3%) (9,2%) (0_,1)
C1%$5 Silica 900 198 0.32 1250 1550 31.5 2.7 90 1130
Fume (1) (0.22) (1.47) (1.82) (3.5%) (0.3%) (92%) (0.11)Cl%P0.5 Silica 900 198 0.32 1250 1550 31.5 2.7 90 1130
Fume (1) (0.22) (1.47) (1.82) (3-_%) (0.3%) (9.2%) (0.I1)C1%$3S5 Silica 900 98 0.32 1250 1550 31.5 2.7 90 1130
Fume (I) (0.22) (I.47) (1.82) (3.5%) (0.3%) (9.2%) ((3.11)
Note: Ad. = additive(latex or silica fume), C =cement, W= water,S = sand.CA =coarse aggregates,Mel. = melment.
AEA = airentrainingagent,DCI= corrosioninhibitor
Values inparanthesesareratioof weight of materialto weight of cement.
27
Table 4.2. Matrix Composition for Mix Series A, B, and C
(Proportions given by weight)
MixID [ Ad. C [Total S CA• I w olControl -- 1 0.28 0..'-t4 1.47 1.82 3.5 0.5% 9.2%
A -- 1 0.28 0.34 1.47 1.82 3.5 0.5% 9.2% --
B Latex 1 0.11 0.30 1.47 1.82 3.5 0.3% 9.2% 0.21
C Silica 1 0.22 0.32 1.47 1.82 3.5 0.3% 9.2% 0.11Fume
Note: Ad. = additive (latexor silica fume), C = cement,W = water, S = sand,CA = coarse aggregates,Mel. = melmemt.
AEA= airenlrainingagent,13(21= corrosioninhibitor
Table 4.3. Typical Fiber Content by Weight as Used in This Study
VIa Fiber Weight 2Steel 1% 132
2% 2641% 15.3
Polypropylene 2% 30.60.15% 2.3
1. Volume fractionof fibersused in thisstudy2. Poundsof fibers per cubic yard of fiber reinforcexlconcrete
28
Concerning the polypropylenefibers,twofiber lengths were uused because the supplier
discontinued the manufaculm of 0.75-in. long polypropylene fibers during the program. Thus,
mixes AI%P0.V5 and A2%P0.75 contained polypropylene fibers 0.75-in. long, while mixes
A I%S3P0.5, A2%S3P0.5, B 1%P0.5, and CI%P0.5 contained polypropylenc fibers 0.50-in.
long. Furthermore, an additional mix containing 0.15% by volume of polypropylene fibers
was prepared. This mix was investigated upon request from the SHRP advisorygroup, and
reflects mixes currently recommended by polypmpylene fiber producers for pavement
applications to control plastic shrinkage.
29
5
Mixing and Curing Procedures
5.1 Mixing Procedure
Each batch was mixed in drum mixer with a capacity of either 1 ft3 or 0.5 ft3, depending on
the number of specimens to be prepared for each series of tests. Small batches were
necessary because of the large number of different test parameters, the limited availability
of test equipment for the testing time (24 hours), and the lesser variability of fiber volume
fraction between specimens. The following steps were followed during the mixing
process. First, gravel and sand were mixed for approximately 1 minute. Then cement was
added and was mixed with the sand and gravel for another 1 minute. This was followed by
the slow addition of approximately 75% of the tap water and the superplasticizer while the
mixer was rotated back and forth about its axis to ensure an even distribution of water
within the mix. The AEA was then added, followed by DCI which was mixed with the
remaining 25% of the tap water used.
It is worth noting that the DCI was purposely added toward the end of the mixing process
because it acted as an accelerator, thus increasing the rate of concrete hardening and thereby
reducing workability.
The mixer was moved back and forth a few times, after all component materials (except the
fibers) were added, to ensure proper and uniform mixing. Finally, fibers were added to the
mix through a sieve (with 0.5-in.-square openings) to guarantee random fiber distribution
and minimize segregation and balling. Altogether, the mixing time took approximately 5 to
6 minutes.
31
After completion of the batch, the mix wa_,poured into the appropriate molds, which were
then placed on a vibrating table. The vibrating process was continued for approximately 2minutes.
5.2 Curing Procedure
Curing of all HESFRC specimens was can-ied out as follows: after placement, the
specimens were kept in their plastic molds for 24 hours, covered with a plastic sheet; the
specimens were then removed from their molds and placed in plastic bags at room
temperature until the time of testing. It was decided by SHRP project advisory group that
the ASTM-AASHTO [2] standard procedure for moist-curing would not be followed for all
HESFRC mixes. The reason for that was to simulate the actual conditions selected mixes
will be subjected to in practice, because they are expected to be used for repair of highways
and bridge decks that must be open to traffic within 24 hours. Proper moist-curing, as
recommended by ASTM-AASHTO, is not possible under such conditions.
5.3 Properties of Fresh Mix
Measurements of HESFRC fresh mix properties were obtained. These measurements
included air content, workability (by inverted slump cone), temperature, and unit weight
(Table 5.1).
Air content was measured by the pressure method (ASTM C 231 or AASHTO [3]) via a
pressure meter with a base capacity of 0.25 ft3. The device (brand name Press-Ur-Meter) is
made by Watts Company, Seattle, Washington. Vinsol resin was used as the primary AEA;
it has the advantage of reducing bleeding and leads to better concrete placing, enhanced
durability, greater freeze and thaw resistance, and enhanced resistance to wetting and
drying as well as to heating and cooling cycles. Best results are obtained when the air
content is kept between 3% to 6%; air content less than 3% gives little improvement, and
air content greater than 6% produces loss of the HESFRC compressive strength. In the
current investigation, a range of 4% to 6% air content was maintained for all mixes (Table
5.1). It was generally observed during trial mixing that a slight increase in the amount of
32
Table 5.1. HESFRC Plastic Properties
Mix ID Unit Weight Inverted Cone Temperature Air Content
(lb/ft3) Test (seconds) (OF) (%)
Control 146.6 23 69 4A1%S3 150.23 18 70 2.5A2%S3 147 25 68 3.5A1%S5 152.02 23 77 7Al%P0.75 138.88 18 70 5A2%P0.75 133.64 25 78.8 9A1%S3S5 141.6 16 75 5A2%S3S5 135.45 26 74 8Al%S3P0.5 147.13 20 79 4.5A2%S3P0.5 154.7 13 77 6.5
B 1%S5 146.1 6 77 5.75Bl%P0.5 148.5 9 79 6
C1%$5 141.8 12 75 6.75C1%P0.5 145.76 7 74 6C1%$3S5 150 7 77 7
33
AEA beyond 6% produces a significant reduction in the strength, which can bc attributed to
the increase in the volume of air voids that _c AEA produces in the mix.
The workability test was conducted by the inverted cone test rather than the slump test. The
procedure was carried out according to reco_,nendations in the report of American
Concrete Institute (ACI) Committee 544 [1] on fiber reinforced concrete as follows: the
standard metal slump cone was inverted ancLmounted on two pieces of plywood placed 3
in. above a pan placed on the ground. The mix was poured into the inverted cone and was
forced to flow out by means of a hand-held vibrator gently dropped through the mix. The
time needed for the mix to flow out of the cone was recorded (Table 5.1).
The initial temperature and unit weight of the fresh fiber reinforced concrete mixes were
also measured. The unit weight was measured according to ASTM C 138-81 [4] standard
procedures, using the 0.25-ft 3 base portion of the pressure meter. The unit weight was
taken after the sample was properly vibrated. Initial temperature was taken using a
thermomcter marked from 0 to 100OF.It was generally observed that the variation in the
temperature over the first 20 minutes was insignificant (less than lop) in all mixes.
Table 5.1 summarizes the fresh properties of all mixes used in this investigation. A
correlation was observed between the amount of air in the mix and the unit weight: the
higher the air content, the lower the plastic unit weight.
The addition of 1% to 2% by volume of polvpropylene fibers caused a noticeable reduction
in the unit weight of the mix, thus leading to a substantial reduction in the compressive
strength. This was observed particularly in mixes Al%P0.75 and A2%P0.75, shown in
Table 5.1, in which long fibers were used. However, mixes B1%P0.5 and C1%P0.5,
containing 1% by volume of 0.5-in.-long polypropylene fibers, showed little or no
reduction in the unit weight. This finding was attributed to the smaller volume fraction of
shorter fibers and to the fact that latex and microsilica, which were mostly used with the
mixes containing 0.5-in.-long fibers, act as dense fillers and improve the workability of themix.
The plastic unit weight of mix A2%S3S5 (i.e., the hybrid mix containing 1% each by
volume of 30/50 and 50/50 hooked steel fibers; Table 4.1 and Fig. 4.2) was observed to be
low relative to the A series mixes because of the relatively high air content (8%). This high
air content and low plastic unit weight were attributed to the large volume of voids present
in the mix, believed to be caused primarily by the presence of 1% by volume of 50/50
hooked steel fibers, which are 2 in. long.
34
5.4 References
i. ACI Committee 544. Measurement of Properties of Fiber Reinforced Concrete. ACI
Material Journal, 85, no. 6, (November/December 1988): 583-593.
2. ASTM Standards. Standard Practice for Mala'ng and Curing Concrete Test Specimens
in the Laboratory. ASTM C 192-90a, vol. 04.02.
3. ASTM Standards. Standard Test Method for Air Content of Freshly Mixed Concrete
by the Pressure Method. ASTM C 231-91, vol. 04.02.
4. ASTM Standards. Standard Test Method for Unit Weight, Yield, and Air Content
(Gravimetric) of Concrete. ASTM C 138-81, vol. 04.02.
35
6
Compression Tests
6.1 Experimental Program
The compression tests were subdivided into three major groups: (1) series A, consisting of
HESFRC mixes having two values of fiber volume fractions (1% and 2% by volume of
concrete), two types of fibers (hooked steel and polypropylene), and for the hooked fibers,
two lengths (30 and 50 mm); (2) series B, consisting of HESFRC mixes containing 1%
fibers by volume and 10% latex solids by weight of cement; and (3) series C, consisting of
HESFRC mixes containing 1% fibers by volume plus 10% microsilica (silica fume) by
weight of cement. A flowchart of the testing program is shown in Fig. 6.1.
For each mix, standard cylindrical specimens were prepared for testing at 1, 3, 7, and 28
days. At least three specimens were tested for each parameter. Since the normal cylinder
size used in this investigation was 4 x 8 in., 6 x 12-in. cylinders were also prepared and
tested at 1 day to provide some correlation between the two sizes. Table 6.1 shows the
number and size of specimens tested for each mix and the type of test performed.
Specimen ID notation is explained in Fig. 6.2.
6.2 Test Apparatus and Procedure
Each time series (time of 1, 3, 7 and 28 days) was subjectedto two types of tests: (1) a
nondestructive test to measure the static modulus of elasticity (Ec) and (2) a destructive test
consisting of the complete stress-strain curve.
37
Table 6.1. Number of Specimens Tested
Mix Series tFiber Fiber Numberof CylindersTestedType Type Volume 4 x 8 in. 6 x12 in.
Fraction Cr- E + Ee o - E
Vf (%) Test Conducted at (days)1 3 7 28 1
HES A Control 0 3 3 3 3 2
HES A 30/50 1 3 3 3 3 2HES A 30/50 2 3 3 3 3 2HES A 50/50 I 3 3 3 3 2HES A PP 1 3 3 3 3 2
HES A PP 2 3 3 3 3 2HES A 30/50 + PP 1 3 3 3 3 2HES A 30/50 + PP 2 3 3 3 3 2lIES A 30/50 + 50/50 1 3 3 3 3 2HES A 30/50 + 50/50 2 3 3 3 3 2
HES + LA B 50/50 I 3 3 3 3 2HES + LA B PP 1 3 3 3 3 2HES + LA B Control 0 3 3 3 3
lIES + SF C 50/50 1 3 3 3 3 2
lIES + SF C PP 1 3 3 3 3 2
HES + SF C 30/50 + 50/50 1 3 3 3 3 2
Notes:LA= latex;PP= polypropylene;SF= silicafume;o - e = stressstraincurveF-.e= elasticmodulus.
38
+e.._ .
E
l-l- ,,e l N
o
g_
" _ _'_ ,,
E m_
0 _'_ _"
g _
I gtg_ NIl
- 71,_!° I_ "
39
1D 48 fc 1
- Specimen Number (1, 2, or 3)
- A = Average of all specimens
- S = Standard deviation
- fc = Compressive and elastic modulus
- fr = Flexural
- ft = Splitting tensile
Size of Cylinder
48 =4 x8in.
¢_12= 6x 12 in.
_[ime of Testing,
. ID = 1 day
- 3D = 3 days
- 7D = 7 days
- 28D = 28 days
Fig. 6.2 - Specimen ID Code.
40
Figs. 6.3 and 6.4 show the setups used for the elastic modulus and complete stress-strain
curve tests, respectively. In each case, the load was measured by a load ceil, while the
deformation was measured using three linear voltage differential transducers (LVDTs)
placed at 120° intervals around the specimen. The stress-strain curve in compression was
obtained for all cylinders tested. The curve provided information on the strength and
ductility. The three curves obtained from the three identical cylinders of each series were
averaged to obtain the average stress-strain curve for the series. Average curves for
different series were compared to clarify the influence of time, specimen size, and various
parameters such as fiber content, fiber type, and the addition of either rnicrosilica or latex.
All measurements were recorded via a data acquisition system, using voltage signals from
the LVDTs and the load cell of the testing machine.
The elastic modulus test was performed on 4 x 8-in. specimens only. The fixture used for
this type of test (Fig. 6.3) consisted of two aluminum rings separated by temporary bracing
that held the top and bottom rings apart at exactly 4-in. gauge length. The bracing was
removed after the two rings were fixed to the concrete cylinder, to aUow for free movement
of the tings. The movement between the two rings was measured by three LVDTs placed at
1200 intervals around the cylinder. A 600-kips capacity Instron universal testing machine
equipped with a swivel head platen was used for all tests. Each specimen was loaded by the
strain-controlled method at a rate of 0.0005 in./sec, and the load was increased up to 50%
of the anticipated strength, which was assumed to be equal to the strength of the control
specimen. Before testing, each specimen was loaded and reloaded twice up to 10% of ]'c
to take care of all loose joints and reduce as much aspossible the curvilinear response that
would otherwise distort the initial portion of the curve. The fixture used to determine the
modulus of elasticity was used up to maximum or peak load. The fucture was removed
beyond the peak load to avoid damage. Thus, the strain recorded thereafter represented the
strain obtained from the platen displacement, as is described next.
Once the elastic modulus test was completed, the rings were removed and the cylinder was
tested up to failure (Fig. 6.4). Here, three LVDTs placed at 120° intervals between the
platens of the testing machine were used to record the deformation of the specimen. The
imposed displacement was carded out until the resistance on the descending branch of the
load deformation curve was less than 10% of the peak stress.
The collected data were reduced and averaged, and various plots were obtained for each
specimen and for the average of each series. The procedure followed for data reduction and
averaging is explained next.
41
Fig. 6.3 - Test Set-up for Measurement of Elastic Modulus
42
Fig. 6.4 - Test Set-up Used to Determine the Stress-Strain Response in Compression
43
Table 6.2. Summary of the Average Values of f'c and Ec Obtained for EachTime Series
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Stren[th (ksi)
Control IIM8fcA 4,129.61 5.08
Control 1D612fcA --- 4.485
Control 3D48fcA 4r155.04 6.55
Control 7D48fcA 4T038.84 6.92
Control 28D48fcA 3,793.71 7.00
A 1%S3 1D48fcA 4,408.78 5.97
A1%S3 1D612fcA .... 5.575
A1%S3 3IM8fcA 3_975.16 6.66
A 1%S3 7D48 fcA 4r644.38 7.54
A 1%S3 281348fcA 4,777.67 7.67I
A2%S3 1D48fcA 3,843.79 6.07
A2%S3 1D612fcA --- 4.65
A2%S3 3IM8fcA 4,093.25 6.71
A2%S3 7IM8feA 4r364.66 7.55
A2%S3 28IMSfcA 6r402.53 7.60
A1%S5 1D48fcA 2r698.22 5.05
A1%S5 ID612fcA -- 5.6
A1%S5 3D48fcA 3,496.97 5.72
A1%S5 7D48fcA 3,522.72 5.98
A1%S5 28D48fcA 3,678.96 6.30
A 1%P0.75 1D48fcA 2r926.07 4.15
Al%P0.75 1D612fcA -- 4.525
Al%P0.75 3IM8fcA 3,121.67 4.95
A 1%P0.75 7IMSfcA 3,247.98 5.83
A 1%P0.75 28D48fcA 2,970.69 5.56
continued on next page
44
Table 6.2. Summary of the Average Values of f'c and Ec Obtained forEach Time Series; continued
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Strength (ksi)
A2%P0.75 1D48fcA 2,785.07 3.07
A2%P0.75 1D612fcA -- 2.6
A2%P0.75 3D48feA 2,996.18 4.36
A2%P0.75 7D48fcA 2,676.45 4.58
A2%P0.75 28D48fcA 2,653.86 4.77
A1%S3S5 11M8fcA 2,922.02 5.51
A1%S3S5 ID612fcA --- 4.085
A1%S3S5 3IM8fcA 3r830.36 6.26
A1%S3S5 7D48fcA 3T566.36 6.93
A1%S3S5 28IM8fcA 3,943.39 7.88
A2%S3S5 IIM8fcA 2,548.26 3.20
A2%S3S5 ID612fcA --- 5.065
A2%S3S5 3IM8fcA 2,818.70 3.38
A2%S3S5 7D48fcA 3,402.38 5.34
A2%S3S5 28D48fcA 3,457.09 6.91
A1%S3P0.5 1D48fcA 2r485.30 3.38
Al%S3P0.5 1D612fcA --- 3.65
A1%S3P0.5 3IM8fcA 2,860.27 3.87
Al%S3P0.5 7D48fcA 3;045.06 4.47
AI%S3P0.5 28IM8fcA 2,706.07 4.90
A2%S3P0.5 1D48fcA 1,515.02 4.70
A2%S3P0.5 1D612fcA -- 3.675
A2%S3P0.5 3IM8fcA 3,529.95 5.17
A2%S3P0.5 7D48fcA 2,992.13 5.50
A2%S3P0.5 28IM8fcA 3,438.7 6.04
continued on next page
45
Table 6.2. Summary of the Average Values of f'c and Ec Obtained forEach Time Series; continued
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Strength (ksi)
B0%Con llMSfcA 2.272.3 4.34
B0%Con 3IM8fcA 3r756.00 6.25
B0%Con 7IMSfcA 3,840.00 6.17
B0%Con 28D48fcA 3,510.00 8.13
B 1%S5 11M8fcA 3,143.51 4.50
B 1%S5 1D612fcA -- 3.19
B 1%S5 3IMSfcA 4,161.98 5.75
B 1%S5 7D48fcA 3r458.95 5.17
B1%S5 28IM8fcA 7r495.01 6.45
B1%P0.5 11M8fcA 2,265.77 2.93
B1%P0.5 1D612fcA -- 3.05
B 1%P0.5 3D48fcA 2,794.65 4.31
B 1%P0.5 7D48 fcA 2,857.79 4.47
B 1%P0.5 28IM8fcA 61600.03 5.79
C 1%S5 1D48fcA 2r476.80 5A6
C1%$5 1D612fcA -- 5.415
C1%S5 3IM8fcA 1r972.88 5.90
C1%$5 7IM8feA 3r658.34 7.55
C1%S5 28IM8fcA 4,094.45 8.40
Cl%P0.5 1D48fcA 2,813.06 3.45
C1%P0.5 113612fcA -- 3.9
C1%P0.5 3IM8fcA 3_636.84 4.81
C 1%P0.5 7IMSfeA 3r387.24 5.58
C1%P0.5 28IM8fcA 2,923.68 5.89
C1%S3S5 1D48feA 3,283.33 4.78
C1%$3S5 1D612fcA -- 4.675
C 1%S3S5 3D48feA 4,254.05 5.49
C 1%S3S5 7IM8fcA 3r447.03 7.34
C1%$3S5 28IM8fcA 3,204.25 7.40
46
6.3 Data Analysis and Test Results
Table 6.2 summarizes the average values of the compressive strength, fc, and elastic
modulus for each mix tested at 1, 3, 7, and 28 days. Note that the average values of fc
represent the average of three 4 x 8-in. and two 6 x 12-in. cylinders. Details on the values
of fc and Ec for each individual specimen, as well as the average and standard deviation
for each time series, can be found in Appendix A (Tables A.1 to A.16).
The data collected from the load ceil and the LVDTs were reduced and averaged by means
of computer programs written in FORTRAN and BASIC. Therefore, the reduced data
recorded consisted of (1) the load in kips and (2) the displacement in inches. Several
programs were used to arrive at the final plots shown in following sections. These
programs were either developed specifically for this project or obtained from different
sources [i, 5, and 6]. The methods and assumptions used in arriving at the final plots for
both the modulus of elasticity and the entire stress-strain curves are explained next.
For the modulus of elasticity, a computer program written in BASIC [6] was used to
reduce the recorded data from kips and inches to stress units (kips per square inch) and
strain units (i.e., in./in.). The program initially starts by reading each set of data points
consisting of the load and the corresponding displacement. If the encountered value of the
load is negative, the program skips this set until it encounters the first positive load in the
file. The physical interpretation of the change of the load sign from negative to positive is
that the point of contact between the swivel head attached to the load cell and the cylinder
has been attained. This point is set as the origin on the stress-strain curve. Therefore, the
absolute stress versus absolute strain values can now be computed as follows:
Pi-eo07 = A
di- do
Ei = LGL
where
cri = Absolute compressive stress corresponding to the ith set of data
Po = Initial compressive load
47
Pi = Compressive load measured relative to Po
A = Cross-sectional area of the 4 x :g-in.cylinder (12.57 in2)
Ei = Absolute initial strain corresponding to tri
do = Initial displacement corresponding to load Po
di = Displacement corresponding to load Pi
LGL = Gauge length (4 in.)
It was observed that the initial portion of the stress-strain curve was curvilinear over a small
stress range. To account for this effect in the computation of the secant modulus of
elasticity Ec, the methodology described in ASTM C 469, AASHTO, and ACI was
followed [1, 2, and 6]. The secant modulus was taken as the slope of the line joining the
maximum point (of coordinates Pi and di, here taken equal to 50% of anticipated
compressive strength) and a point corresponding to a strain of 50 microstrain (coordinates
Po and do).
The average Ec value for each time series was calculated from the Ec values obtained from
each specimen.
Three programs were used to convert the data obtained from the data acquisition system to
the final form, the entire stress-strain curves shown in the following sections. The
procedures used for data reduction and averaging were automated by means of a central
batch file to achieve efficiency and minimize the possibility of error.
The purpose of the In'st program was to reduce the relative load versus relative
displacement data sets to absolute values of stresses and corresponding strains (i.e.,
relative to the origin) in a manner similar to the procedure explained earlier for the modulus
of elasticity. The absolute stress and absolute strain values for each specimen were stored
in separate f'des, then used as input data fries to calculate the average stress versus average
strain coordinates for each test series [7]. Individual stress-strain curves for each specimen
and average curves for the specimens of the same series were then plotted.
A special averaging technique was followed to produce the average curve for each time
series. First, the average peak stress and the corresponding strain at peak stress were
obtained by averaging the peak stresses recorded for the individual test specimens and theircorresponding strain values.
The averaging process for the remaining data was carried out as follows. First, the peak
point was determined for each specimen. It was found that using 50 points to describe the
48
ascending branch provided a suitably smooth curve. Therefore, the stresses on the
ascending branch of each stress-strain curve were taken at 50 equal strain intervals. In
general, the value of this interval was different for each specimen, since each had a slightly
different strain at the peak. The average stress value at each interval was then calculated,
and this value was taken as the stress of the average curve at the corresponding strain
interval, based on the peak point of the average curve. The same approach was used to
calculate the coordinates of the average stress-strain curve along the descending branch.
Finally, the stress-strain curves were systematically plotted for (1) each specimen of the
same series and the series average; (2) the average curves comparing each time series, that
is, 1, 3, 7, and 28 days (Appendix A, Figs. A. 1 to A.79); and (3) the average curves at 1
day comparing the 4 x 8-in. and 6 x 12-in. cylinders. Additional figures were also
produced to compare average maximum strengths and elastic moduli observed for each
series at various times.
6.3.1 Stress versus Strain Response with Time
This section focuses on the effect of time on the stress-strain response of all HESFRC
mixes [5]. The effect of microsilica and latex on the stress-strain relationship with time is
also examined and compared with previous studies [3, 4, and 8]. Selected average graphs
of the stress versus strain response with time as well as the stress versus strain response
for different cylinder sizes (at 1 day) are shown this section.
In general, the requirement for achieving a compressive strength of 5 ksi or greater at 1 day
was met for almost all mixes except those containing polypropylene fibers.
Fig. 6.5 shows the stress-strain curves of the control mix tested at 1, 3, 7, and 28 days.
The effect of specimen size at 1 day is illustrated in Fig. 6.6. It can be observed that (I) the
compressive strength increases from about 5 ksi at one day, to about 6.5 ksi at 3 days, to 7
ksi at 7 days and remains at about 7 ksi at 28 days; (2) little ductility can be counted on
following the peak load; and (3) the strength of the 6 x 12-in. cylinders is, as expected,
slightly lower (here about 11% ) than that obtained from the 4 x 8-in. cylinders.
Fig. 6.7 shows the effect of adding 1% by volume of 30/50 hooked steel fibers. It is
observed that although 3"c slightly increased in comparison with the control mix (17%),
the area under the curve is much larger, thus indicating a substantial increase in ductility
and energy absorption to failure. The figure also shows that the slope of the descending
49
o_|L FRC - Tes'_ at 1,3,7, and 28 days
o__ Control HIx
r_ _ Cylinder size. 4' x 8'
v .................."'"Fll! --- 7days
,00 .0! .02 .03 .04 .05 .06
STRAIN
Fig. 6.5 - Stress vs. Strain Response of Control Mix with Time
o_m
FRC - Test at I dayK- Control HIx
m
- Cylinder slze_ 4' x B° ¢_nd6" x 12'_,
Ul u_ 4' x 8'A
fu_ , ,,
Ldn'¢4 II--q3
_d
1_" I I I I I I I I I I.00 .Or .02 .03 .04 .05 .06
STRAIN
Fig. 6.6 - Effect of Cylinder Size on the Stress-Strain Response of the Control Mix
5O
FRC - Test at 1,3,7,and 28 dagsO3
30/50 Hooked Flbers, t/d=60
_/_ = I% ( o? Concrete)rN_ ° °
Cgilnder slze,4' x 8'
1 d_ W
................3 dags
V_ 7 dQgs
_ 28 dags
I 1 I 1 I I 1 1 I,00 .01 .02 .03 .04 ,05 ,06
STRAIM
Fig. 6.7 - Stress vs. Strain Response of Mix A1%S3 with Time
i l FRC - Test at I da,j
30/50 Hooked Fibers,t/d=60
Vf = 17.( oF Concrete)
Cgtinderslze,4" x 8' and 6' x 12'
_ 4' × 8'V
, 6' x 12'_ .,=.: ',
I--rY_ "-.
o _'T"|w
I I I I I I I 1 I I 1.00 .01 .Oe .03 .04 .05 .06
STRAIM
Fig. 6.8 - Effect of Cylinder Size on the Stress-Strain Response of Mix AI %S3
51
branch slightly decreases with an increase in the compressive strength. The increase in fc
for the series tested at 3, 7, and 28 days was 11.6%, 26.3%, and 28.5%, respectively, in
comparison with the series tested at 1 day Fig. 6.8 compares the compressive strength
obtained from 4 x 8-in. and 6 x 12-in. cylinders tested at 1 day. Generally, the 4 x 8-in.
cylinders lead to a slightly higher compressive strength than the 6 x 12-in. cylinders.
Fig. 6.9 shows the test results obtained from testing the mixes containing 2% by volume
of concrete of 30/50 hooked steel fibers. "Ihe trend observed in this figure follows that
observed in Fi_. 6.7; that is, the slope of the descending portion of the 28-day curve
increases when compared with the 1-, 3-: and 7-day curves, indicating a loss of ductility
beyond the 7-day life. It is not clear whether this is simply due to normal variability in the
results, or whether age leads to additional brittleness. Fig. 6.10 compares the stress-strain
curves obtained from 4 x 8-in. and 6 x 12-in. cylinders tested at 1 day. Unlike the mix
containing 1% by volume of 30/50 fibers, the mix containing 2% of 30/50 fibers showed a
substantial decrease in compressive strength (25% decrease). This result could not be
explained but is reported as observed.
The stress-strain curves of the mix containing 50/50 hooked steel fibers are plotted in Fig.
6.11. Contrary to the observations made on Figs. 6.7 and 6.9, the slope of the descending
portion for all time series does not show any significant increase with time, indicating that
the loss of ductility with time is insignificant. Fig. 6.12 shows a comparison between the
curves obtained from the 4 x 8-in. and 6 x 12-in. cylinders tested at 1 day. Here, the
compressive strength of the 6 x 12-in. cylinder is approximately 11% higher than the
strength of the 4 x 8-in. cylinder.
Fig. 6.13 describes the mix containing 1% by volume of polypropylene fibers. The figure
clearly shows two major drawbacks in using polypropylene fibers. The first is the
significant drop in fc (-20%) at 1 day relative to the control mix. The reason for this sharp
drop is not very clear and may be attributed to the low elastic modulus of the polypropylene
fibers and their poor bonding properties in comparison with steel fibers.
The second drawback can be explained by observing the descending branches of the 7- and
28- day curves. Unlike the 30/50 steel fiber mix at 1% and 2% volume fraction, the
polypropylene mix at 1% volume fraction shows a significantly lower ductility. This lower
ductility may also be explained by the lower elastic modulus and poorer bond properties of
polypropylene fibers. A comparison of the stress-strain curves for the 4 x 8-in. and 6 x 12-
in. cylinders is illustrated in Fig. 6.14.
52
o4 L_ __ FRC - Test =t 1,3,7, =nd 28 d=yso_ 30/50 Hooked Fibers, L/d=60
,'jl_ll..i,% VF = 27. ( oF Concrete)
iL,\ =,..,,.x..L -]/ \'t",, '..............._<'o_=
,_ °%, •
,,,-,l
,00 .01 ,02 ,03 ,04 .05 ,06
STRAIN
Fig. 6.9 - Stress vs. Strain Response of Mix A2%S3 with Time
m l-i- FRC - Test =t I dayr_ 30/50 Hooked Flbers, I/d=60
- i- VF = 2?. ( oF Concre'ce)_0- _ CyLinder size/ 4' x 8' _nd 6' x 12'
/ \_ -U1
_-/.. \ , _.x.,v - I"", \ . 6' x 12'(/) _-C/)i.d -n" ei -
_ -
"iI I I I I I I l I l I,00 .01 .02 .03 ,04 .05 ,06
STRAIN
Fig. 6.10 - Effect of Cylinder Size on the Stress-Strain Response of Mix A2%S3
53
i l FRC - Test at 1,3,7,and 28 dczys
50/150Hooked Fibers, t/d=lO0
V,_ = I_.(of Concrete)
Cy|Inder size.4' x 8'
° A_ I day
V) tn I_ _._ _ --- - 7 daysO_ _ 28 doysLLI_rV :.
V_ r_
Od
- .................I I I I I I I I I I I ,
.00 .01 .oe .03 .04 .05 .06
STRAIN
Fig. 6.11 - Stress vs. Strain Response of Mix A1%S5 with Time
QdI
FRC - Test at I day
r_- 50/50 Hooked Fibers, t/d=10O
- VF' = I_.(of Concrete)
- Cylinder slze,4' x 8' and 6' x 12'
__ - {'\
_ '._ \ 4' x 8'Y' f
v ___ 6' x 12"
LLJ $t
' ,.,,__°
I I I I I I I I I I I.00 .01 .Oe .03 .04 .05 .06
STRAIN
Fig. 6.12 - Effect of Cylinder Size on the Stress-Strain Response of Mix AI %S5
54
°dLL FRC - Test at 1,3,7, nnd 28 daysN| 3/4' Potgpropyiene Fibers
.I VF = IZ (oF Concrete)!-- Ctjtlnder size, 4' x 8'
"_ L i_ --1 do,y'
_ °%°°°°°°°.........
.00 .01 .02 .03 .04 ,05 ,06
STRAIN
Fig.6.13 - Stress vs. Strain Response of Mix AI %P0.75 with Time
odB
FRC - Test at I day
r_- 3/4' Poigpropylene Fibers- VF = I% (oF Concrete)
_- Cylinder size, 4' x 8' and 6' x 12'
"U_y_, 4'x8'V
;; 6' x 12'
ni
1 I I I I 1 I,00 .01 ,02 .03 .04 .05 .06
STRAIN
Fig.6.14. Effectof CylinderSizeonthe Stress.StrainResponseof Mix AI %P0.75
55
Fig. 6.15 shows the same type of polypropylene fibers used at a volume fraction equal to
2% by weight of concrete. Here, the reduction in the compressive strength at 1 day is
approximately 40% of the control mix and almost double the decrease observed for the mix
containing 1% by volume of polypropylene fibers. Fig. 6.16 shows a comparison between
the 4 x 8-in. and 6 x 12-in. cylinders. The figure clearly shows that the compressive
strength of the 4 x 8-in. cylinder is slightly higher than that for the 6 x 12-in. one.
Fig. 6.17 illust'ates the results for the hybrid mix containing 30/50 + 50/50 hooked steel
fibers at a total of 1% by volume. A hybrid_mix is defined as a mix that (1) contains more
than one type of fiber or (2) contains the same type of fibers with varying aspect ratios.
Several conclusions can be arrived at from Fig. 6.17: (1) the strength at 3, 7, and 28 days
increases 14%, 25%, and 43%, respectively, when compared with the i-day strength; (2)
the slope of the descending branch decreases with an increase in strength. In Fig. 6.18, the
stress-strain curves obtained from 4 x 8-in and 6 x 12-in. cylinders tested at 1 day are
compared. The trend observed here confmns the trend observed with other mixes.
Fig. 6.19 describes the curves for the same: mix as for Fig. 6.18, except that the volume
fraction of fibers is doubled (2%). A 37% decrease is observed in the compressive strength
at 1 day relative to the plain matrix. However, the strength picks up at a later age and good
ductility is observed. Fig. 6.20 shows the stress-strain curves obtained from 4 x 8-in. and
6 x 12-in. cylinders tested at 1 day.
Similar graphs were plotted and analyzed for all the other test series. They are included in
Appendix A, Figs. A.80 to A.94. However, conclusions drawn from the test results are
summarized in section 6.4.
6.3.2 Stress versus Strain Response." Comparison between Series
The purpose of this section is to compare the stress-strain relationships of series A, B, and
C mixes tested at 1 and 28 days. It should be noted that specific comparisons of the
compressive strength values are discussed in section 6.3.3.
Fig. 6.21 compares mix series A tested at 1 day, each mix having a different type of fiber at
a volume fraction of 1%. The figure clearly shows that the mix containing the 30/50 fibers
leads to the highest compressive strength and the largest area under the stress-strain curve,
and the mix containing polypropylene fiber's lead the lowest compressive strength and
ductility.
56
05
FRC - Test cLt1.3.7,omd 28 do_s
r_- 3/4' PoLypropgteneFibersVF = 27.( oF'Concrete)
,._- Cytmnderslze,4' x 8'
_.__-i dory
,:., ...............3 d=_s
,00 .01 ,02 .03 .04 ,05 .06
STRAIN
Fig. 6.15 - Stress vs. Strain Response of Mix A2%P0.75 with Time
05m
FRC m Test (_tI dcLy3/4' PotypropyteneFlbers
- Vf" = 2% (oF Concrete)
- Cytlnderslze,4' x 8' ond 6' x 12"om
Ul u-)- 4' x 8'i"-" - 6' x 12'
C_bJ -rv_
ai
P
I I I I I I I I I I I.00 ,01 ,02 ,03 .04 ,05 36
STRAIN
Fig.6.16. Effectof CylinderSizeon the Stress-StrainResponseof MixA2%P0.75
57
FRC - Tes¢ =t 1,3,7, and 28 days
r_i Hybr'ld HIx30/50 + 50/50 Hooked Fiber's
VF := lY. ( oF ConcreCe)
_1 U_ Cytlnder" size, 4' x 8'I_" __1 day
(/) _: ,, 3 days(/)I.d - - -7 daysn/c_I-- • _28 days(/1
o
I I I I 1 I I I I,00 ,01 .0;' .03 .04 ,05 .06
STRAIN
Fig. 6.17 - Stress vs. Strain Response of Mix A1%S3S5 with Time
c_
t FRC - Test _t 1 d=u.,
r_ Hgbrld HIx30/50 + 50/50 Hooked Fibers
o
_o VF = IZ ( o£ Concre_ce)
_L' _ Cylinder" size, 4" x 8' and 6' x 12'
v I- / _ ___4'xe'
(_ ,¢: -6' x 12'
,00 .01 .02 ,03 ,04 .05 .06
STRAIH
Fig. 6.18. Effect of Cylinder Size on the Stress-Strain Response of Mix AI %S3S5
58
FRC - Test Qt 1,3,7,and 28 days
HgbrldHlx30/50 + 50/50 Hooked Fibers
_ VF = 2% (oF Concrete)
_ CyLinder slze, 4' x 8'
v I day
V3 _ _ ",, ...............3 daysbJ ",. _ - -7 dags
rv m ", 28 days
:" "'"'"_C'.-....
i i
I l ! I.00 .01 .02 .03 .04 .05 .06
STRAIN
Fig. 6.19 - Stress vs. Strain Response of Mix A2%S3S5 with Time
o_
FRC - Test at I day
HybridHIx30/50 + 50/50 Hooked Flbers
VF = E_.(oF Concrete)/-%
," ',, C_tlnder" size, 4' x 8' _nd 6' x 12',,, u'i -.v 4' x 8'
_: ' "- 6' x I:_'_ 4,,
n," ei -.
-o
.00 .01 .0;_ .03 .04 .05 .06
STRAIN
Fig. 6.20 - Effect of Cylinder Size on the Stress-Strain Response of Mix A2%S3S5
59
- FRC - Test ot I da_
/ Ct)mp_ro_lve EvoLu_lonot" DIFFerent Mixes
_ ,_: .:: .,.: V_' = t_ . ,_X_ r- i,', CL.+tmdersize, x
4 8
_' , ': ...... 30/50 Hooked Steel'_. -/
m:1- _/_ _, "': - - - 50/50 Hooked St;eeL
| • . •
dE+\ ",.+
.-J L _.,..
.00 .01 .02 03 .04 .05 ,06
STRAIN
Fig. 6.21 - Effect of Fiber Type on the 1 Day Stress-Strain Response (Vf=I%)
°
;'e. FRC - Tes+ ot 28 doLJs
Conporotlve [votuotlon
. :,. : of DIFFerent Hlxes,,o :' ' : V f = IZBt %
:!I- tlt \ ... 30,/50Hooked$'teet!-!l \ "" - - - .o,/5oHookeds,,,,i- :1 _,"', _ z,/a"eo,_prop_,ene
_i-+1 \::',_,'I "(,'..."',.
I-:1 "_:.. "'-C -.%, b
.00 .01 .02 ,03 ,04 .05 .06
STRAIH
Fig. 6.22 - Effect of Fiber Type on the 28 Day Stress-Strain Response (Vf=l%)
6O
Fig. 6.22 compares the same three mixes tested at 28 days. The figure shows that the 30/50
mix has the highest compressive strength but undergoes a sharp drop in the post peak
response. In contrast, the 50/50 mix shows a milder post peak slope. It may be concluded
that the response of the 50/50 mix at 28 days is better than that of the 30/50 mix. The
response of the polypropylene mix relative to the other mixes was poorer, in terms of both
strength and ductility.
Fig. 6.23 shows the mixes of series A at 1% volume fraction of fibers tested at 28 days. It
can be observed that both the 30/50 and 30/50 + 50/50 mixes gave the highest compressive
strength and behaved very similarly. However, they showed a sharper slope increase in the
post peak response as compared with the 50/50 mix, which in turn showed a slightly lower
compressive strength. The 30/50 + polypropylene mix gave the lowest compressive
strength and the smallest area under the stress-strain curve.
Fig. 6.24 compares three mixes of series A containing 2% fibers and tested at 28 days. The
30/50 mix gave the best overall response. The performance of the 30/50 + 50/50 mix was
similar to that of the 30/50 mix, except that the compressive strength was slightly lower.
The response of the 30/50 + polypropylene mix was acceptable, but with noticeably lower
compressive strength in comparison with the two other mixes.
Similar graphs were plotted and analyzed for all the other parameters studied. They are
included in Appendix A, Figs. A.95 to A. 104. However, conclusions drawn from the test
results are summarized in section 6.4.
6.3.3 Compressive Strength
The purpose of this section is to compare the compressive strength of various mixes,
observe its variation with time, and draw relevant conclusions. Typical curves are
described next. However, the graphs developed for all parameters are included in Appendix
A, Figs. A.105 to A.111.
Fig. 6.25 shows the variation of .fc with time for mix series A containing 1% by volume
of fibers. Mixes 30/50 and 50/50 and hybrid mix 30/50 + 50/50 gave the required
minimum compressive strength of 5 ksi at 1 day. The other two mixes, containing
polypropylene and polypropylene + 30/50 hooked steel fibers lead, respectively, to 20%
and 33% reductions in fc at 1 day compared with the control mix.
61
o_
FRC - Tes_ ,,t: 28 d=ysl_ Conpar_clve EvGlu_lon
oF !OIFFeren_cHlxesVF = I;':
L/1u'J Cy|l.der slze_ 4" x 8'v ___ 30/50 Hooked S'tee(
(/) _: ......... 50/50 Hooked Steel
L,J ... - - -30/50 + 50/50 Hooked S_.eetry_ ...I-- 30/50 Hooked Steel Fibers(,_ '%.. ----
'.%. + 1/2' Potypropgtene
"..•...
.,,..
""-.,,..., .....
.00 .01 .02 .03 ,04 .05 .06
STRAIN
Fig. 6.23 - Effect of Using 2 Types of Fiber on the 28 Day Response (Vf=1%)
I_ FRC - Test at 28 daysComporatlve Evatu='l:lonof OIfFerent Mixes
__ _ Ct,jIJndersize1 4' x 8"V
30/50 Hooked Steer
(/) _ - "- -30/50 + 50/50 Hooked Steer(/)I,I : 30/50 Hooked S'ceei Fibers
I-- + I/P' Pol_Jpropgtene(/)
o.i
°
,00 .01 .02 ,03 .04 .05 .06
STRAIN
Fig. 6.24. Effect of Using 2 Types of Fiber on the 28 Day Response (Vf=2%)
62
The mix containing 30/50 hooked steel fibers showed an average increase in fc of
approximately 10% over the control mix at all time intervals. Next in performance was the
hybrid mix, 30/50 + 50/50, which led to a 10% average reduction in strength compared
with the 30/50 mix. As expected, the 50/50 mix showed an increase in fc over time.
However, that increase was less than the increase observed with the control mix. The
strength reduction observed in the 50/50 mix is believed to be due to the large volume of air
entrapped during mixing of the fibers. This explanation is supported by the air void tests
conducted on all three mixes and shown in Table 5.1, in which air contents of 3.5%, 5%,
and 7% were obtained for the 30/50, 30/50 + 50/50, and 50/50 mixes, respectively.
Fig. 6.26 also shows a reduction in strength when polypropylene fibers are used.
Fig. 6.26 describes the results of the same mixes discussed in Fig. 6.25, except that the
volume fraction of fibers has changed from 1% to 2%. The figure shows that the 30/50 mix
still leads to an overall increase in fc over the control mix. The 30/50 and the
polypropylene + 30/50 mixes gave the required minimum 5 ksi compressive strength,
whereas other mixes did not meet this criterion. The 30/50 and polypropylene + 30/50
mixes gave a 20% increase and a 7% reduction in fc at 1 day compared with the control
mix, whereas the 30/50 + 50/50 and polypropylene mixes gave a 33% reduction in fc at 1
day compared with the control mix. The presence of at least 1% by volume of 30/50 fibers
in the polypropylene + 30/50 mix enhanced the overall behavior, even in the presence of
1% polypropylene fibers. The 30/50 + 50/50 hybrid mix did not give satisfactory results
because of large air voids (8%), as shown in Table 5.1. Fig. 6.26 shows that the 28-day
strength of the 30/50 + 50/50 hybrid mix was approximately equal to that of the control
mix. The polypropylene mix gave the lowest strength, with an average 30% reduction
compared with the control mix at all time intervals. It is believed that this was primarily due
to the high volume of air entrapped in the mix (9% air content).
Fig. 6.27 provides a comparative evaluation of the effect of latex and silica fume on fc for
the mix containing 1% by volume of 50/50 fibers. The figure shows that latex reduces the
strength from that of the plain fiber reinforced concrete (FRC) mix by approximately 11%
at 1 and 7 days. At 28 days, the strength of the latex-modified mix approaches that of the
plain mix. The compressive strength of the silica-fume-modified mix at 1 and 3 days does
not change significantly. However, at 7 and 28 days, the compressive strength increases by
7% and 6%, respectively, over the plain FRC mix.
63
8
7 mr
_ 4 ..............._. 1%
3 ..... "'" Control30/50
2 ---¢3 50/50= Polypropylene
1 - 30/50 + 50/50.L Polypropylene+ 30/50
! I ! i
1 3 7 28
Time, days
Fig. 6.25 - Compressive Strength, f'= vs. Time (Vf = 1%).
8
mm_om_om--
o So¢'
5
_- lume Fraction : 2%3 ET
.... u---- Control2 _ 30/50
Polypropylene1 a 30/50 + 50/50
• Polypropylene+ 30/50I ! ! !
1 3 7 28
Time, days
Fig. 6.26 - Compressive Strength, f'c vs. Time (Vf = 2%).
64
9Type of Fibers: 50/50 Hooked Steel
8 Vf = 1%
7 x- x
am
(n
"_ 5
G;.. 4
--'_--- Control3o Plain FRC
2 -- Latex Modified FRCZ_ Silica Fume Modified FRC
1 • Control+Latex
! I I I
1 3 7 28
Time, days
Fig. 6.27- Compressive Strength, f'c vs. Time, 50/50 Steel Fibers, (Vf=l%)
9Type of Fibers: Polypropylene
8 Vf = 1%
7 ,., -,41" ------t1(
om s
5 - ---_"
u" 4
3 ---_--- Controlo PlainFRC
2 -- LatexModified FRC
1 Zk Silica Fume ModifiedFRC•¢ Control + Latex
O I I 1 !
1 3 7 28
Time, days
Fig. 6.28- Compressive Strength, f'c vs. Time, Polypropylene Fibers, (Vf=1%)
65
Fig. 6.28 provides a comparative evaluation of the effect of latex and silica fume on fc for
the mix containing 1% by volume of polypropylene fibers. None of the mixes with fibers,
microsilica, or latex gave the required minimum 1-day strength of 5 ksi. The strength of the
latex-modified mix was 15%, 11%, 20%, and 2% lower than the silica-fume-modified mix
tested at 1, 3, 7, and 28 days, respectively. Furthermore, the strength of the silica fume
mix was very close to the plain FRC mix over time. The latex mix, however, showed an
average decrease of 30%, 13%, and 23% at 1, 3, and 7 days, respectively. At 28 days, the
increase in fc in both the latex and silica fume mixes over the plain FRC mix was only2%.
6.3.4 Elastic Modulus
The purpose of this section is to compare the variation in the elastic modulus of various
mixes with time and comment on its behavior [5]. It should be noted that the scatter
observed in the elastic modulus tests was much larger than that observed for the
compressive strength tests.
Fig. 6.29 shows a plot of the measured elastic modulus, Ec, versus the square root of the
measured compressive strength, .fc, for all cylinders tested. As expected, except for a few
points, it can be observed that Ec and _c are directly prooortional. The regression line for
the data is given by the following equation:
Ec = - 210,000 + 50,000_c (psi)
The conditional standard deviation of the data is about 460,000 psi, and the coefficient of
correlation is 0.747. The two lines plotted in Fig. 6.29 to bound the data are 1.5 standard
deviations away from the mean and bound 87% of the data.
Fig. 6.30 shows the results of series A mixes using 1% fibers by volume. The 30/50 mix
showed a higher elastic modulus than the control mix at 1, 3, 7, and 28 days. Next in
performance came the hybrid mix with 30/50 + 50/50 fibers. The 50/50 mix showed a
slightly lower elastic modulus. The mixes containing polypropylene showed the lowest Ec,
whereas the hybrid mix containing 30/50 + polypropylene showed a slightly lower Ec value
than that containing polypropylene fibers only. The elastic modulus at 1 day for the 30/50
fibers (Table 6.2) was 7% higher than that of the control mix. However, the elastic moduli
at 1 day for the 30/50 + 50/50, polypropylene, 50/50, and polypropylene + 30/50 mixes
were, respectively, 30%, 30%, 35%, and 40% lower than that of the control mix.
66
600O
o Control e_5000' • AlO/_._
4000 & A1%P0.75
- • AZ,].PO.TS /. ".'11,.'-¢_%_
u,I = A1%S3P0.5• A2%S3P0.5
2000 • B1%S5= Bl%P0.5
= C1%$5
1000 • C1%P0.5• C1%$35
0 ; | f u
0 20 40 60 80 100
Fig. 6.29 - Elastic Modulus, E¢ vs.
67
5000Volume Fraction = 1% ,., -o
4500
400O
3500
•- 3000
2500
o" .... i---- ControlU.I 2000o :30150@ Vf = 1%
1500 o 50/50 @ Vf = 1%
1000 ,, PolypropyleneFibers @ Vf = 1%- 30/50 + 50/50 @ Vf=1%
500 A Polyprowlene + 30/50 @ Vf = 1%
I I I T
1 3 7 28
Time, days
Fig. 6.30 - Elastic Modulus, Ec vs. Time, (Vr = 1%).
o°l /Volume Fraction = 2%6000
5000 t
iiiiI ,..............................2000 1 o 30/50
_oooll :;°oi;"o'°°:';,:o0 1 , _- Polypropylene+ 30/50I I I
1 3 7 28
Time, days
Fig. 6.31 - Elastic Modulus, E= vs. Time, (Vf = 2%).
68
Furthermore, the mixes containing polypropylene fibers showed an increase in Ec up to the
seventh day, then a slight decrease at 28 days. At 28 days, the elastic moduli for the 30/50
+ 50/50 and 50/50 mixes showed no significant changes from that of the control mix.
However, it was observed that the 30/50 fibers gave an Ec value 26% higher than that
given by the control mix, whereas the polypropylene mix and the polypropylene + 30/50
mix gave moduli that were, respectively, 22% and 29% lower than the control mix.
Fig. 6.31 illustrates the results for mix series A containing 2% by volume of fibers. The
30/50 fibers led to no significant change at 1, 3, and 7 days. However, the Ec value at 28
days increased by almost 16% from that of the corresponding control mix. The 30/50 +
50/50 hybrid mix showed a steady increase in the elastic modulus with time, with Ec being
38%, 32%, 16%, and 10% lower than that of the control mix. The elastic modulus of the
polypropylene mix showed no significant change over time, and it was approximately 30%
lower than that observed for the control mix. The polypropylene + 30/50 hybrid mix
showed a sharp increase in Ec at 3 days compared with that at 1 day, whereas little further
change at 3, 7, and 28 days was observed. The Ec value at 1, 3, 7, and 28 days for the
polypropylene + 30/50 hybrid mix was, respectively, 63%, 15%, 25%, and 9% lower than
that given by the control mix.
Other graphs were plotted and analysed. They are shown in Appendix A, Figs. A.112 to
A.120. However, the related conclusions are summarized in section 6.4.
6.4 Conclusions
6.4.1 Stress-Strain Response in Compression
The following conclusions regarding the stress-strain response in compression of
HESFRC composites are drawn:
1. The requirement for HESFRC mixes to achieve a compressive strength of 5 ksi or
greater at 1 day was generally satisfied by the control mix, as well as by all mixes
containing steel fibers. The mixes containing polypropylene fibers and latex did not
satisfy this requirement.
69
2. Reinforcing a concrete matrix with steel fibers significantly enhances the ductility at 1,
3, 7, and 28 days. The control mix without fibers tested at 1, 3, 7, and 28 days
indicates that the mix has no ductility beyond the peak stress.
3. The compressive strengths values obtai:aed at 1 day fi:om the 6 x 12-in. cylinders
ranged from 29% below to 13% above those obtained from the 4 x 8-in. cylinders
(except for one test series that was 58% higher and was discarded from the data). The
average compressive strength for aUmixes at 1 day for the 6 x 12-in. cylinders was
3.9% lower than that obtained for the 4 x 8-in. cylinders.
4. It was generally observed that the presence of polypropylene at 1% and 2% volume
fractions causes a significant decrease in the compressive strength. Doubling the
volume fraction of polypropylene fibers from 1% to 2% causes a significant reduction
in the 1-day compressive strength (-40%). It was concluded that the response of the
polypropylene fiber mix relative to all other fiber concrete mixes was unsatisfactory, in
terms of both strength and ductility.
5. The slope of the descending branch tends to increase with time for almost all mixes of
series A, thus indicating loss in ductility with time. This decreased ductility is believed
to be due to an increase in the compressive strength with time.
6. The 30/50 mix containing 2% steel fibers by volume showed enhanced performance
when tested at all time series in terms of both compressive strength and ductility, which
can be attributed to the enhanced interracial bond properties of the 30/50 fibers
compared with the polypropylene fibers and the better uniformity in distribution when
compared with the 50/50 steel fibers.
7. The hybrid mix containing 1% of 30/50 + 50/50 hooked steel fibers showed a 50%
increase in fc at 28 days relative to the I-day strength. Furthermore, it was observed
that doubling the volume fraction of fibers from 1% to 2% causes a significant decrease
in the compressive strength relative to the control matrix. This decrease was attributed
to the large air voids entrapped in the mix because of the presence of 1% by volume of
50/50 steel fibers.
8. For mix series A, the use of 30/50 hooked steel fibers, 50/50 hooked steel fibers, or a
combination of both causes no significant changes in the compressive strength and
ductility. However, replacing half the 30/50 fibers with an equivalent volume fraction
of polypropylene fibers reduces the 1-day strength by almost 50%, thus significantly
7O
decreasing the area under the stress-strain curve (i.e., lower ductility). Therefore, there
is reason to believe that the presence of polypropylene fibers in any HESFRC mix is
not desirable if meant to improve the compression properties, even at volume fractions
as low as 0.5%.
9. Latex significantly improves the workability of HESFRC mixes, as also observed
previously [3, 4, and 8] but causes a significant reduction in the compressive
properties at early ages. The ductility of the HESFRC mixes containing latex improves
with time because of the improved interracial bond properties latex provides. This was
true when both the steel and the polypropylene fibers were used.
10. Contrary to the results reported in the technical literature for plain concrete, the addition
of silica fume had no significant effect, at early age, on the stress-strain response of the
polypropylene, 50/50, and 50/50 + 30/50 HESFRC mixes containing 1% by volume of
fibers.
6.4.2 Elastic Modulus
The following conclusions regarding the elastic modulus, Ec, of all HESFRC mixes are
drawn from this study:
1. Except for the 30/50 mix at 1% and 2% volume fraction of steel fibers, the elastic
modulus of all mixes was in general less than that of the control mix.
2. As expected, strong correlation was found between measured Ec and measured _[f'c •
3. The 30/50 mix at 1% and 2% volume fractions of steel fibers showed the highest elastic
modulus at all times (1, 3, 7 and 28 days) among all mixes of series A. The increase in
the elastic modulus for this mix relative to the control matrix was more significant at 28
days than at 1, 3, and 7 days.
4. The elastic modulus of the 50/50 and 30/50 + 50/50 hybrid mixes at 1% and 2%volume fraction of steel fibers was less than that observed for the control mix at all
times.
5. HESFRC mixes containing 1% and 2% by volume of polypropylene fibers showed thelowest values for the elastic modulus.
71
6. Latex modification of HESFRC mixes compared with the unreinforced (control + latex)
mix and the plain FRC mix (series A) si_,mificanfly increased Ec as the HESFRC mixes
containing polypropylene or 50/50 fibers aged with time; however, latex addition had
little effect at I, 3, and 7 days.
7. The elastic modulus of all HESFRC mixes plus silica fume containing 1% by volume
of polypropylene, 50/50, or 50/50 + 30/50 fibers was less than that for the control mix
(i.e., plain c 9ncrete mix). A slight improvement was observed for the elastic modulus
of the hybrid (30/50 + 50/50) mix containing silica fume at 1 and 3 days relative to the
plain FRC. However, very little improvement was observed at 7 and 28 days.
6.5 Recommendations
1. The use of 1% to 2% by volume of 30/50 hooked steel fibers gave best composite
properties in both the fresh and hardenexl states. It caused a notable increase in the
compressive strength, elastic modulus, and ductility when compared with all other
HESFRC mixes.
2. Next in performance was the use of 1% by volume of either 30/50 + 50/50 steel fibers
or 50/50 steel fibers. Both mixes performed very similarly in terms of compressive
strength, elastic modulus, and stress-strain response. The 1-day compressive strength
of these mixes exceeded the required rrfinirnum of 5 ksi.
3. Mixes containing 1% to 2% by volume of polypropylene fibers showed deterioration in
the compressive stress-strain response when compared with the control mix. Therefore,
the use of polypropylene fibers alone to improve strength and elastic modulus is not
desirable. However, the use of 1% by volume of polypropylene fibers in conjunction
with 1% by volume of 30/50 hooked steel fibers in the same HESFRC mix leads to a
slight improvement in the compressive stress-strain properties. Polypropylene fibers
may also improve other properties of concrete not tested in this investigation.
4. Although latex improved the workability, of HESFRC mixes, it is not desirable to use
latex with HESFRC mixes for the purpose of improving early age properties.
However, latex improves the long-term compressive stress-strain response of
HESFRC mixes, and is known to improve durability [3, 4, and 8].
72
5. Silica fume had no notable effect on the compressive strength at 1 day. However, it
significantly increased the compressive strength of HESFRC mixes at later ages.
73
6.6 References
1. ACI Committee 318. Building Code Requirements for Reinforced Concrete (AC1318-
83). American Concrete Institute, Detroit, Michigan, 1983.
2. ASTM Standards. Standard Test Method for Static Modulus of Elasticity and
Poisson's Ratio of Concrete in Compression. ASTM C 469-87a, vol. 04.02.
3. Bharyava, J.K. Polymer-Modified Concrete for Overlays: Strength and Development
Characteristics. In Application of Polymer to Concrete, SP-69, American Concrete
Institute, Detroit 1981: 205-218.
4. Mason, J.A. Overview of Current Research on Polymer Concrete: Material and Future
Needs. In Application of Polymer to Concrete, SP-69, American Concrete Institute,
Detroit 1981: 1-20.
5. Naaman, A.E. and F.M. Alkhairi. Fresh and Hardened Properties of High Early
Strength Fiber Reinforced Concrete (HESFRC): Compressive Stress-Strain
Relationship and Elastic Modulus with Time. UMCE Report No. 91-08, 1991.
6. Najm, H. Mechanical Properties of High Performance Cement Based Composites.
Ph.D. Dissertation, Department of Civil Engineering, University of Michigan, 1992.
7. Otter, D. SIFCON Under Cyclic and Monotonic Loading. Ph.D. Dissertation,
Department of Civil Engineering, University of Michigan, 1989.
8. Soroushian, P. F. Aouadi, and M. Naji. Latex-Modified Carbon Fiber Reinforced
Mortar. ACIMaterialJournal, 88, no. 1, (January/February 1991): 11-18.
74
7
Bending Tests
7.1 Experimental Program
Bending tests were subdivided into three major groups: (1) series A, consisting of
HESFRC mixes having two volume fractions of fibers (1% and 2% by volume of
concrete), two types of fiber materials (hooked steel fibers and polypropylene fibers), and
for the hooked fibers, two lengths, 30 and 50 ram; (2) series B, consisting of HESFRC
mixes containing 1% fibers by volume and 10%latex solids by weight of cemen_ and (3)
series C, consisting of HESFRC mixes containing 1%fibers by volume and 10%
microsilica (silica fume) by weight of cement. Fig. 7.1 shows a flowchart summarizing the
test program. The flowchart is the same as the one used for the compression specimens
(Fig. 5.1), except that a series of tests containing 0.15% by volume of polypropylene
fibers was added, thus changing the total number of series to 17 instead of 16. Flexural
tests were conducted to study the flexural properties of all HESFRC mixes [6], namely, the
load-deflection response in bending.
For the flexural tests, at least two specimens, 4 x 4 x 16 in., were prepared for each
parameter; they were tested at 1, 7, and 28 days (Table 7.1). Average load-deflection and
load-strain curves were compared to clarify the influence of time and various parameters,
such as fiber content, fiber type, and the addition of either microsilica or latex. Specimen
ID notation is shown in Fig. 7.2.
75
Table 7.1. Number of Specimens Tested
Mix Series tFiber Fiber Numberof Beams Tested
Type Type Volume 4 x 4 x 16 in.Fraction Flexural
Vf (%) Test Conducted at (days)1 7 28
HES A Control 0 2 2 2
lIES A 30/50 1 2 2 2HES A 30/50 2 2 2 2lIES A 50/50 1 2 2 2lIES A PP 0.15 2 2 2lIES A PP 1 2 2 2HES A PP 2 2 2 2HES A 30/50 + PP 1 2 2 2lIES A 30/50 + PP 2 2 2 2lIES A 30/50 + 50/50 1 2 2 2HES A 30/50 + 50/50 2 2 2 2
lIES + LA B 50/50 1 2 2 2I-IES+ LA B PP I 2 2 2
I-n=_S+ LA B 30[50+ 50/50 I 2 2 2lIES + SF c 50/50 1 9 2 2HES + SF C PP 1 2 2 2lIES + SF C 30/50 + 50/50 1 2 2 2
Notes: LA = latex; PP = polypropylene; SF = silica fume
76
'7"7
1D 48 fc 1I
. Specimen Number (1, 2, or 3)
- A = Average of all specimens
- S = Standard deviation
T.xnt.u£.T.
- fc -- Compressive and elastic modulus
. fr = Flexurai
- ft = Splitting tensile
Size of Cylinder
48 =4 x8in.
612 = 6x 12 in.
Time of Testine
- 1D = 1 day
-3D = 3 days
-7D -- 7 days
.28D -- 28 days
Fig. 7.2 - Specimen ID Code.
78
7.2 Test Apparatus and Procedure
7.2.1 Apparatus
The dimensions of the beams were 4 x4 xl6 in. tested in third-point loading, at a span of
12 in., as recommended by ASTM C 1018 [1].
Three types of measurements were recorded for each beam: (1) the load from the load cell
of the testing machine, (2) the vertical deflection at the third points, and (3) the elongation
(strain capacity) measured over a 4 in. gauge length within the constant moment region.
Two LVDT' s were placed under the point loads at opposite sides of the specimen to record
the average vertical deflection. A third LVDT was placed under the beam along the extreme
bottom fiber to measure the elongation within the flexural span. The setup is shown in
Figs 7.3 and 7.4. The load versus average vertical deflection and load versus strain
capacity were recorded via a data acquisition system. It should be noted that the strain
capacity measurement provided information on the strain capacity of a particular fiber
reinforced concrete mix before and after cracking. Also, no correction was made for the
possible deflections (settlements) at the supports, since the supports were very rigid.
The flexural tests were carried out using a 30-kip capacity Instron universal testing machine
using the displacement-controlled method (Fig. 7.5).
7.2.2 Definition of Toughness lndex
Once the load-deflection response in bending was plotted, the toughness index values at
various deflections were computed according to ASTM C 1018 [1]. The toughness index
is a relative measure of the areaunderthe load-deflection curve, and can be correlated with
the energy absorption capacity of the material. The definition of toughness index according
to ACTM C 1018 is illustrated in Fig. 7.6. First, consider the ideal elastic, perfectly plastic
load- deflection response of the top part. The areaunder the curve up to the first cracking
of the beam, or deviation from linearity, is considered the reference area. The deflection at
cracking is termed _first-craek and is used as the reference deflection. The toughness index
up to any deflection 8 > C_m_'t-crackis defined as the ratio of the areaunder the curve up to 8
to the area underthe curve up to 8lust-crack.In the case of an ideal elastic, perfectly plastic
response, the indices I5, I10, and I30 have values of 5, 10, and 30, respectively. The
79
PFromActuator
SpreadBemrn
: !:!-.. ... . .
.... • : ii:i"..:. ::
• .i ... . ..... ..i..• ;:i::. '.:'." , .
: :era: i :;)! '.. .:.. .
4,0" " ".....": " • " ..... .::" :":......,....:: i,_ • '"ii,.:.::,:,:,,,:,._,,' -,i,,,)',;!!i?!,,i,,.i ,::_i.i;,i;,.i: ,, >,::_:,:....•",:.,,:,:.: , " , ,,:::K,i!:,,:,::::;i ': .:..",:" ......
• ,,.,,,, ,:;illI_I.:_,I:: i:i!:_:,,,:,, ,:.;-.:i,,:::,::::! _"_ i ::i:>!i]:::ii:i::i_:.,._.:• ::.... -:_: ._"::i _-:: , ...... _ ":": ....... .. . . .
AttachedFrame
SValnLVDT
Deflection DeflectionLVDT(front) LVDT(back)
I _ | _l, Nl.l_ _1_ _ I_.,_._li-_p-_ l_.,_. r i_.._ .,._i-_ r_l_-- I
2.0" 4.0" 4.0" 4.0" Z.O"
Fig. 7.3- Sketch of the Test Set-up for Flexural Tests
8O
Fig. 7.4 - Test Set-up for the Flexural Tests
81
Fig. 7.5 - Instrumentation Used for the Flexural Tests
82
¢1<o.J
' ,fl
_! ! i i .1 3 5.5 15.5
l DEFLECTION(_ first-crack
< ' ' A0 = I--J I
I !I
II
!!
' CIII!I
' D
I
1 3 5.5
8 l DEFLECTIONfirst-crack
Fig.7.6- Toughness Index in Bending: top) Definition for an ElasticPerfectly Plastic Response; bottom) Typical Curves for FRC
83
deflection at which I5 is measured is three, times the deflection at cracking, _ust-crack. The
deflection at which I10 is measured is 5.58first-crack,and that for which 130 is measured is
15.58f'trst-crack.For a real load-deflection curve, the value of 15 may be smaller or larger
than 5, depending on whether the curve after first cracking falls below the horizontal line or
above it. Hence, in the bottom part of Fig. "r.6, curves A and B have I5 values larger than
5, and curves C, D, and E have 15 values srraller than 5. A similar approach can be
followed to describe the other toughness indices. In the current ASTM C 1018, the
reference deflection and corresponding area under the curve are taken from the same fiber
reinforced concrete test specimen. Howevel, a control plain concrete specimen can be
tested separately, and its area under the curve up to failure can be used as a reference.
These two approaches were followed in section 7.3.4, and led in some cases to
substantially different results.
7.3 Data Analysis and Tests Results
This section summarizes the results obtainecl from the flexural tests: (1) the load versus
deflection and load versus strain capacity at different ages; (2) a comparative evaluation of
the load versus deflection and load versus su'ain capacity relationships for different mixes at
1 and 28 days; (3) the variation of flexural strength with time; and (4) the variation of
various toughness indices with time.
Average strength results and toughness indices are given in Table 7.2. Individual results
for each specimen are summarized in appendix B, Table B. 1, while plots of various time
series and response curves are given in the following sections.
7.3.1 Load versus Deflection and Strain Capacity Response with Time
Here, the effect of time on the load versus deflection and load versus slxain capacity
response of all HESFRC mixes is examined. The effect of microsilica and latex with time is
also studied. Some observations are made, and figures showing the load versus deflection
and load versus strain capacity response obsa_rvedfor each individual specimen and a
representative average curve for each mix are shown.
84
Table 7.2. Summary of Main Flexural Test Results
Mix ID Specimen fr First 15 I5 I 10 I10 120 120ID (psi) Crack First Control First Control First Control
Stress Crack Crack Crack
(psi)
Control 1DfrA 646.88 --- _.......... ,_-.....Control rDfrA '" 600.0 --- [i ........... -- "- - "'" -Control 28DfrA 790.31 ...................A1%S3 1DfrA 937.5 693.8 6.77 9.44 14.00 20.01 23.83 34.38Al%S3 VDfrA 905.25 703.1 8.18 6.68 15.37 12.36 25.12 20.07_d%S3 28DfrA 937.5 750.0 6.73 5.74 11.48 9.66 17.71 14.82_2%S3 1DfrA 1545.0 1312.5 6.45 33.26 9.91 53.77 ......_2%S3 VDfrA 1866.56 1443.8 6.32 15.59 9.47 24.22 12.69 33.06_2%S3 28DfrA 1817.81 1481.3 6.00 13.95 10.14 24.69 .....M%S5 1DfrA 1451.25 637.5 9.66 13.03 23.01 31.58 43.74 60.39A,1%S5 rDfrA 1575.0 956.3 7.69 9.87 16.39 21.39 28.88 37.94_i%s5 28DfrA 1668.75 768.8 9.07 6.88 19.88 14.75 34.44 25.36
_,.15%P0.5 1DfrA 537.19 516 2.16 . 3.1 ...... . ....._,.15%P0.5 7DfrA 787.5 626.3 4.56 2.87 ........... __,.15%P0.5 28DfrA 843.8 843.8 1.7 2.35 ...........
_1%P0.5 IDfrA ....644.06 _..356.3 6.94 11.13 10.56 17.30 .....5_1__%_PP__:_5_....... 7DffA 701.25 300.0 8.73 . 3.23 15.54 5.20. ' 25.25 8.00M%P0.5 28DfrA 938.44 375.0 8.51 3.44 14.24 5.31 22.48 8.00_2%P0.5 1DfrA 459.38 328.1 9.57 4.85 14.12 6.89 24.48 1L54
42%P0.5 iDfrA 619.69 337.5 7...68 3.34 15.14 5.95 25.90 9.724,2%P0.5 28DfrA 632.81 581.3 1.26 3.03 1.44 4.52 1.71 6.68A,1%S3S5 1DfrA 999.38 806.3 3.60 5.33 7.19 11.34 14.22 23.07M%S3S5 VDfrA 1410.94 975.0 3.82 2.50 8.27 4.87 16.94 9.48_t-i%S3S5......28DfrA i321.88 768.8 8.61 8.26 17.26 16.53 27.82 26.61n.2%S3S5 1DfrA 1517.81 1031.3 7.91 33.48 13.81 61.24 22.36 101.43_2%S3S5 iDfrA 1757.81 515.6 9.45 7.62 27.56 21.82 51.78 40.80...._.%S3S5 28DfrA 1912.5 1106.3 8.79 10.96 17.88 22.58 28.52 36.17M%S3P0.5 1DffA 647.81 328.1 10.03 8.01 21.30 16.77 36.85 28.84
1%S3P0.5' 7DffA 770.63 675.0 4.29 7.36 7.43 13.41 11.25 20.80_i%-S31_3.5 28DfrA -909.38 675.0 7.78 5.86 13.81 10A7 21.53 15.70_2%S3P0.5 1DfrA 714.38 300.0 11.11 7.22 24.48 15.45 44.57 27.82_.%S3P0.5 VDfrA 934.69 450.0 10.33 7.05 21.26 14.13 34.30 22.58_2%S3P0.5 28DfrA 1054.69 862.5 8.08 8.33 13.11 13.54 19.80 20.47
continued on next page
85
Table 7.2. Summary of Main Flexural Test Results; continued
Mix ID Specimen fr First I5 15 I 10 110 I20 I20ID (psi) Crack ]First Control First Control First Control
Stress Crack Crack Crack
(psi)B1%S5 __lDfrA, _ 1007.81 _ 890.63 5.21 36.30 8.34 62.55 .....
III II IIII I
B1%S5 7DfrA 1378.13 1125.0 6.27 14.32 11.27 26.97 17.84 43.55B1%S5 28DfrA 1921.88 1312.5 6.93 16.19 13.25 32.35 20.85 51.81B1%P0.5 IDfi'A 575.63 487.50 4.37 3.51 7.73 6.01 13.37 10.20Bl%P0.5 TDfrA 637.5 571.88 4.41 3.38 7.78 5.73 12.00 8.68B1%P0.5 _SDfrA 871.88 750.00 4.40 2.76 7.66 4.46 12.49 6.96B1%S3S5 IDfrA 1013.44 825.00 6.20 17.04 10.97 31.72 16.60 49.07B1%S3S5 7DfrA 1406.25 1078.1 6.79 12.06 12.86 23.67 20.38 38.03B1%S3S5 _SDfrA 1753.13 1368.8 6.09 14.82 10.70 27.32 16.01 41.75C1%$5 IDfrA 1228.13 1087.5 5.71 26.51 10.63 53.15 17.72 91.51_!%S5 _7DfrA __1449.38 1125.0 6.45 12.83 11.93 24.75 18.42 38.84C1%$5 28DfrA 1978.13 1312.5 7.10 11.85 13.39 23.04 20.23 35_1
21%P0.5 1DfrA 553.13 421.88 5.6 5.57 9.49 9.42 14.07 13.97
21%P0.5 7DfrA 648.75 365.63 I 4.61 3.01 7.,56 4.66 11.13 6.6521%P0.5 28DfrA 787.5 581.25 1.16 2.17 1.38 3.75 1.68 5.94
C!%$3S5 1DfrA 984.38 796.88 6.31 17.25 11.69 33.74 18.40 54.27C1%$3S5 7DfrA 1425.0 843.75 7.74 8.62 15.94 17.88 26.90 30.28C1%$3S5 28DfrA 1350.0 1031.3 6.74 7.59 11.79 13.39 18.71 21.33
86
• No significant change in flexural behavior was observed with increasing age for the test
series containing 1% by volume steel fibers, hooked 50/50 and 30/50 (Figs. 7.7 and
7.8, respectively)
• When 2% 30/50 hooked steel fibers are used, the ductility at seven days increases
significantly compared with that at one day. However, there is little change in the
response at 28 days compared with that observed at seven days (Fig. 7.9).
• The use of polypropylene fibers at Vf = 0.15% does not influence the bending strength
of the HESFRC mixes. Corresponding specimens showed brittle failure at the onset of
cracking (i.e., sudden drop in the load-carrying capacity), with little crack distribution
along the beam. Furthermore, the beams showed little strain capacity before failure
(Figs. 7.10 and 7.11).
• The use of polypropylene fibers at Vf = 1 and 2% also did not lead to any significant
enhancement in bending strength for all time series tested. The failure at 7 and 28 days
was brittle and somewhat similar to that observed for the mix containing 0.15% by
volume of polypropylene fibers. It can be generally concluded that the presence of
polypropylene fibers at low volume fractions (e.g., less than 1%) does not significantly
enhance the fiexural strength compared with the control mix, wheras the use of higher
amounts of polypropylene fibers (e.g., 2%) causes a significant decrease in the flexural
strength. This decrease is perhaps due to the difficulty in mixing 2% by volume of
polypropylene fibers, which may lead to entrapped air and increased porosity. For all
mixes containing polypropylene fibers, it was observed that the first cracking load also
is normally the maximum flexural load sustained by the specimen (Figs. 7.12 and
7.13, respectively).
• The 30/50 + 50/50 mix containing 2% by volume of hooked steel fibers showed
enhanced behavior at 1, 7, and 28 days. Although no significant change was observed
in the ductility of this mix between 1 and 28 days, the flexural strength increased by
almost 15% at 7 days and 20% at 28 days (Figs. 7.14 and 7.15).
• The addition of latex also improved the response with time of the mixes with
polypropylene fibers and the hybrid mixes (30/50 + 50/50) containing 1% fibers by
volume (Figs. 7.16 and 7.17).
Other graphs were plotted and analyzed. They are shown in appendix B, Figs. B. 1 to
B. 16. However, the related conclusions are summarized in section 7.4.
87
c5
oq FRC - Fiexur_t Test _t I,7, _nd 28 days50/50 Hooked Steer Fibers
o_ VF = I;:
rC
_o-,_i ,i ...............I d_gV
<_ _- _'_..
_.1 c,i
M
.O0 ,10 .PO .30 ,40 .50 .60
DEFLECTIDM (;n>
Fig. 7.7 - Effect of Time on Load vs. Deflection Response, 50/50 Steel Fibers, (Vf=l%)
_'- F'RC - Ftexurat Test at 1, 7, and 28 days
c_- 30/50 Hooked Steer Fibers
_C% _ - VF = I%
vi,-.,.._. - - - 7 d_y i
.00 ._0 .eo .30 .40 .50 .soDEFLECTIDM (in)
Fig.7.8- EffectofTimeonLoadvs.DeflectionResponse,30/50SteelFibers,(Vf=1%)
88
FRC - FLexurat Tes_ a_ l, 7, and 28 days
a_ 30/50 Hooked $_ceel Fibers
u_In r___ 1 day
t •
•. - - - 7 d,_y
l::::l 16 \_""-. ;)8 dayI: I '.
tl_ I: • '.
$ "
._j t% °.o
(_ • m.,• q... ;.
_j -..._..:
.00 .10 .Z0 .30 .40 .50 .60
DEFLECTInM (in)Fig. 7.9 - Effect of Time on Load vs. Deflection Response, 30150 Steel Fibers, (Vf=2%)
O_ FRC - FLexur_t Tes_ a± 1,7, _nd 28 da_sI/2" Potypropytene Fibers
0_ Vf' = 0.157.
r< i d_y
,_ ...............7 _sV
28 d_ys
[]
-J ri
.00 .10 .ao .30 .40 .so .60DEFLECTIDM (in)
Fig.7.10- Effectof Timeon Loadvs.DeflectionResponse,1/2" PolypropyleneFibers,(Vf--O.lS%)
89
¢5
o_- FRC - Flexurat Tes_c _ i, 7, ond 2B dogs
- I/2' Poiypropyiene Fibers
o_- V? = I).15%
rx g%_-Ul
_el,__ i _Qy
-- ..................7 d_ys
<_ _r --, - • - 2B d_js[] _ si,
-%. CQ
M
I I I I I I I I I.oo .o3 .o6 .o9 .12 .15
STRAIN CAPACITY (in/in)Fig. 7.11 - Effect of Time on Load vs. Strain Capacity Response, 1/2" Polypropylene
Fibers, (Vf=0.15 %)c_
o_- FRC - F'(exurQt Test _t I,7, _nd 28 d_ys
- I/2' Poiypropy|ene Nix0_- V? = I;:
r_ -ffl
_-
u_ .... 7 d_y
---- 2B d_g
n
_ .....
ib"
I I I""" I I !: I 1 I I I.00 .I0 .20 .30 .40 ,50 ,60
DEFLECTION (in)
Fig. 7.12 - Effect of Time on Load vs. Deflection Response, 1/2" Polypropylene Fibers,
(Vf=l%)
9O
o_ - F'RC - F'texur'ot Tes't ot: 1, 7, nnd 28 do.ys- 1/2" Potyropytene HIx
a_- VF = 2_.
CL _ ...............! day
_. ---7days_-- _ 28 days
%.
.00 .10 .;:)O .30 .40 .SO .60
DEFL.ECTII'IH (in)
Fig. 7.13 - Effect of Time on Load vs. Deflection Response, 1/2" PolypropyleneFibers, (Vf=2 %)
91
.
FRC - Flexura[ Test at I,7, and ;28daysHybrlclNlx
o_ 30/50 + 50/50 Hooked Steel Fibers
v? = 2%f%
U_ :; ".EL r< -,
__ "J I dayv _ i' ................," - - - 7 dag"i
u_ _; ---- 28 dag<:[
(9_ "''.....o
I I I I I I I.00 .lO .20 ,30 .40 .50 ,GO
DEFLECTION (in)
Fig. 7.14 - Effect of Time on Load vs. Deflection Response, 30/50 + 50/50 Steel Fibers,(Vf=2%)
i
c5- FRC - l:IexuraITest _t I,7, _nd 28 days
Hgbrld Mixo_ ,,- -', _ 30/50 + 50/50 Hooked Steel. Fibers
• ... _
Ul " " ...............1 day
-- .... - - - 7 dayY
v ,,_ - ....,,,,._,__. _ 28 d_y
_1r_
o.i-
,__ -
I I I I I I I I i.00 .03 ,06 ,09 .1P ,15
STRAIH CAPACITY (;n/In)
Fig. 7.15 - Effect of Time on Load vs. Strain Capacity Response, 30/50 + 50/50 SteelFibers, (Vf=2 %)
92
o_ F'RC - FLexur'Qt Tes_ a_ L 7, and 28 days!La*cex Mix
06 30/50 + 50/50 Hooked S_eet FibersVf = LX
,_ r_U_ ", ............. 1 day
Y , - - - 7 daq%,# -. •
.o'° •._ : " , __ Z8 day
• %
,. %%
<C _r ... ,,tlm3 °.. •
r_ ""..°.° •_,
•-.. ......... . ...... ...
.oo .zo .eo .30 .40 .so .60DEFLECTIE]I'I (in)
Fig. 7.16 - Effect of Time on Load vs.Deflection Response,Latex,30/50 + 50/50 Steel Fibers, (Vf=]%)
c_m
FRC - Ftexurat Tes_ a_ L 7, and 28 daLjso_ m
m/-- \ La,x .,x06-/ "_ 30/50 + 50/50 Hooked $'_ee[ Fibers
L -.. _ - - - z _,ay"-,.. __ ..,-,,,Y
_' _ rE....'"""'""...... _
_ .." ".... ".<[ ,:- ".... ",,rJ'1 w- o., •
I _: "'"'""'"'""" ........ •"•""•"-
_ ,°°°°°o°
..... ....°
_ -
I i I I I I I I I.00 .03 .06 .09 .la .15
STRAIN CAPACITY (in/in)
Fig. 7.17 - Effect of Time on Load vs. Strain Capacity Response, Latex,30/50 + 50/50 Steel Fibers, (Vf=l%)
93
7.3.2 Load versus Deflection Response: Comparison between Series
This section compares the load versus deflection response for beams made from different
mixes at 1 and 28 days. Only typical examples are discussed in this section. However, the
graphs developed for all parameters are included in appendix B, Figs. B.17 to B.20, and
the related conclusions are presented in seclion 7.4.
• The mix containing 1% by volume of 50/50 steel fibers showed the highest flexural
strength and ductility at 1 day, compared with the mixes with 30/50 steel fibers and
with polypropylene fibers. This can be atu'ibuted to the improved mechanical behavior
of the 50/50 hooked steel fibers, compared with the 30/50 and polypropylene fibers.
The mix with the 50/50 fibers showed average increases of 35 and 150% in the
flexural strength relative to the mixes with 30/50 and polypropylene fibers, respectively
(Fig. 7.18).
• When compared with other hybrid mixes containing 1% by volume of fibers, the 50/50
mix still showed superior load versus deflection response. The 30/50 + 50/50 mix
showed a slight improvement in behavior relative to the 30/50 mix (7% increase). The
behavior of the 50/50 mix was much better than that of the 30/50 + polypropylene mix;
however, the latter was slightly better than the polypropylene mix (Fig. 7.19). It can be
concluded that the presence of polypropylene fibers in HESFRC composites is not
desirable if flexural strength is to be improved.
• At 28 days, the 50/50 mix showed much higher ductility in comparison with all other
plain and hybrid FRC mixes containing 1% by _/olume of fibers (Figs. 7.20). The
flexural strength of the 50/50 mix was 45% higher than that of either the 30/50 or the
polypropylene mix. The polypropylene and 30/50 mixes showed similar flexurai
strength capacities; however, the ductility of the 30/50 mix was much better than that of
the polypropylene mix (Fig. 7.20).
• The 50/50 mix outperformed the 30/50 + 50/50 hybrid mix (23% flexural strength
increase) at 28 days. Both 30/50 and 30/.50 + polypropylene mixes showed a 50%
reduction in the flexural strength compared with the 50/50 mix. These mixes also
showed poor ductility relative to the 30/50 + 50/50 and the 50/50 mixes (Fig. 7.21).
• At one day, the behavior of the mix conlatining 2% by volume of 30/50 fibers was
much better than that of the polypropylene mix containing the same percentage of
fibers. The mix with polypropylene fibers showed 30 and 70% reductions in the
94
m
o_- Plain FRC - Fiexural Test at I dayl Comparative Fva[uatlon
o_- , of Different Mixes- ,'", VF = 17.
m | •
. I _
,,,, 4.x ,.x. __ ", _ Control
U'J I ._. _-,-" ". -. ...............30/50 Hooked SteerI" " •
_F _ ". "'-, _ m --50/50 Hooked Steer
H' ";"4 """. . 1/2 ' Potypropytene
%, %_%
.00 .10 .20 .30 .40 .50 .60
DEFLECTION (in)
Fig. 7.18. Load vs. DeflectionResponsefor Different Mixes, 1 Day,Plain FRC, (Yf=1%)
o_- Plain L Hybrid FRC - FLexure| Test- at I day. Comparative Evaluation- of DIFFerent Mixes
- .'""'". VF = IZ. . . ,I_- ." '. Motd size= 4 x 4 x 16
_/_ - _Controtm
m '.... : 30/50 Hooked Steer
_--_ I-:,"• "''. ..............50/50 Hooked SteerU_ : t ".P-;." L_
r-u_l:;a"_" '-.. ---30/50 + 50/50 Steer_ I-_ _-', "'" .... . 30/50 Hooked FIIoers +
"q_', "'""-.. 1/2' PoLypropI,jtene
CO %_-. "'"......
,.4
.00 .10 .20 .30 .40 .50 .60
DEFLECTIOH (in)
Fig. 7.19 - Load vs. Strain Capacity Responsefor Different Mixes, 1 Day,Plain and Hybrid FRC, (¥'f=1%)
95
o_- ,, Plain FRC - Ftexurai Test at 28 days- ; , Conparatlve Evaluation
O0- _ ', oF DIFFerent HlxesI t
- : ,, v_ = Ix_l-: ",
L-l ', Moldsize, 4' x 4" x IS'- I _ ', _ Control
ID !--;. I_:t" ', ............. 30/50 Hooked Steel
,_t4ii':- ',, - - -50/50 HookedS_eeLI: " •
m I-;.:/11 "--...... - ,,,, .
.00 .10 .20 .30 .40 .50 ,60DEFLECTIBH (in)
Fig.7.20 - Load vs.DeflectionResponsefor Different Mixes,Z8 Days,Plain FRC, (Vf=l%)
o_ Plain I, Hybrid FRC - Flexural Test
b :"""" at ;)8 dauJS. Comparative Evaluation
I-- / "" oF DIFFel-ent Mixes
E/ . v,,=,zi ,, "-.
_f / ", Hold size, 4" x 4' x 16"
Fi/ "',- :o.trolI-i, , ,. * 30/50 Hooked Steel
L_l_L ,,".. ...............50/50 Hooked Steel• ,%,
L"J_-_ ",". - - -30/50 + 50/50 Steel
"; " ......I I I.00 .10 .a0 .30 .40 .50 .60
DEFLECTInH (in)Fig. "7.21- Loadvs.StrainCapacityResponsefor Different Mixes,28 Days,
PlainandHybrid FRC, (Yf=I%)
9d
flexural strength relative to the control mix and the mix with 30/50 fibers, respectively
(Fig. 7.22).
• The 30/50 and 30/50 + 50/50 hybrid mixes showed about the same flexural strength.
However, the 30/50 + 50/50 hybrid mix showed higher ductility than the 30/50 mix.
This suggests that although the 30/50 fibers may contribute equally to strength, the
presence of 50/50 fibers in the hybrid mix significantly enhances ductility (Fig. 7.23).
Figure 7.23 also suggests that eventhough replacing 1% of 30/50 fibers in a mix
containing a total of 2% by volume of fibers with an equivalent volume fraction of
50/50 fibers enhances ductility, the opposite is observed when 1% by volume of
polypropylene fibers is used. The use of 1% by volume of polypropylene fibers in
combination with 1% by volume of 30/50 fibers leads to a reduction in flexural strength
of about 55% compared with the use of 2% by volume of 30/50, or 30/50 + 50/50
fibers.
• The use of 2% by volume of polypropylene fibers compared with the 30/50 steel fibers,
shows significant deterioration in both strength and ductility at 28 days. The strength of
the mix with polypropylene fibers was about one-third that of the mix with 30/50
fibers. Furthermore, the failure of the polypropylene fibers specimens at 28 days was
sudden with little or no crack distribution before first cracking (Fig. 7.24). The overall
response of the specimens with the polypropylene fibers may have also been affected
by the large amount of air entrapped duringmixing.
• The 28-day load versus deflection response of the specimens with 2% by volume of
30/50 fibers was similar to that of the specimens with 30/50 + 50/50 fibers. The 30/50
+ 50/50 mix showed a slight improvement in ductility relative to the 30/50 mix because
of improved mechanical behavior of the 50/50 fibers. The 30/50 + polypropylene
hybrid mix showed a significant reduction in both strength and ductility compared with
either 30/50 or 30/50 + 50/50 mixes (40%). It is believed that this may be due to the
presence of air voids entrapped during mixing of the polypropylene fibers (Fig. 7.25).
• The addition of latex led to about a 30% reduction in the one-day flexural strength of
the 50/50 mix, when compared with plain FRC. Also, the addition of silica fume to the
50/50 mix did not significantly affect the strength or ductility at one day (Fig. 7.26).
• The 28-day flexural load versus deflection response of the 50/50 mix containing either
latex or silica fume showed increases of 15 and 10%, respectively, in flexural strength,
97
c_e-I
B
o_ - Pl=In FRC - Ftexurat Test ,,t ! day- CompQratlve Evatu(_'t;lon
00- _.- of' DIFFerent Mixes- V'_' = 2Z
._. _ -L_
._ : Hol,d size, 4" x 4' x 16'" _ Controt
- •..............30/50 Hooked Steel
<I: _ .... I/2' Potypropylene!-1
-.I _ "'._
... .....
I I I I .... 4..... I I I I I I.0c .zo .20 .30 .40 .so .co
DEFLECTIOM (in)Fig. 7.22 - Load vs. Deflection Response for Different Mixes, 1 Day,
Plain FRC, (Vf=2 %)
om
o_ - Ptnln& H_jbrld FRC - Ftexur_t Test- _t I day. Comparative Ev_tuation
- .'_.."-, of DifFerent Mixes
, V_ = 2"/.I_ -- i "-
_/_ --_ "- "' Motd size, 4' x 4' x 16'
v_ ,,O- tl :' ", -- Control.-:-'" ._. ", '.............30/50 Hooked SteerI/3 --"" ; •
_! :. ", - - -30/50 + 50/50 Steer
_: -ii ". ", . 30/50 Hooked Fibers *l" : •
mNf N ..... ..
,00 .10 .;=0 .30 .40 ,50 ,60
DEFLECTIDN (an)
Fig. 7.23 - Load vs. Strain Capacity Response for Different Mixes, 1 Day,Plain and Hybrid FRC, (Vf=2%)
98
d PialnFRC - Ftexurai Test at 2B da_s
Comporatwe Evotuatlono_ " oF rllFFerent HIxes
VF = 2%O_ :
U_O. _
Hold size, 4' x 4' x 16'v _ -- Contr'ot
u_ : ...............30/50 Hooked Steel
<_ - - - I/2'Potypropytene
"!D 'q"._1
ei
° •
,00 .10 .20 .30 .40 .50 .GO
DEFLECTION (in)Fig. 7.24 - Load vs. Deflection Response for Different Mixes, 28 Days,
Plain FRC, (Vf=2%)
- , Plain 8, Hybrid FRC - Flexurai Test
.- ]"..;',, at 28 days. Comparative Evaluationm- It - , oF DiFFerent Hlxes
=_/ , \ vF =a%
I_-_ ".. ", Mold size, 4' x 4' x 16'
_ "...',, __ co,_ot[-_/¢_ "... ", ...............30/50 Hooked SteelI_ \ ,, - - -3o,5o+5o,5os_,+_
.1,9, "_ "...",. - 30/50 Hooked Fibers +
"".."'-.... 1/2' Polypropylene
,00 .10 ,PO .30 .40 ,50 .60
DEFLECTIDM (in)
Fig. 7.25 - Load vs. Strain Capacity Response for Different Mixes, 28 Days,Plain and Hybrid FRC, (Vf=2%)
99
o_- FRC - Ftexurot Test at I day- Cc,mporatlve Fvatuatlon
0_- 50/50 Hooked Steel Fibersm .'""
:" '. Vt: = IX
:' , "'.. Hold size, 4' x 4' x 16'[-# r-<'-,., :o.,ro
l-+,'/ "-.. +'++-+ - "o-x1_1 ei .....:..
ai
M
.00 ,I0 ,eO ,30 ,40 .50 .60
DEFLECTION (in)Fig. 7.26 - Effect of Additive on Load vs. Deflection Response, 1 Day,
50/50 Steel Fibers, (Vf=l%)
FRC - Fiexurat Test at 28 days
Comparative Evaluationo_ 50/50 Hooked S'l;eetFibers
VF = 1X'.
" Mold size, 4' x 4' x 16'n rC: '.-- "- -- Control
"v _ • _ ...............P|aln FRC
%
'+ - - - SILICoFume
<I_ "' * Latex
"O°°o. ,_
0+ .......................__:.,.:.-.:.:
I I I,00 ,I0 .20 .30 .40 .50 .60
DEFLECTIDM (in)
Fig. 7.27 - Effect of Additive on Load vs. Strain Capacity Response, 1 Day,50/50 Steel Fibers, (Vf=1% I
100
compared with the plain FRC mix. The mix with latex showed higher ductility than
either the plain FRC mix or the FRC mix with silica fume (Fig. 7.27).
7.3.3 Modulus of Rupture or Maximum Flexural Strength
The purpose of this section is to discuss the modulus of rupture (MOR), symbol fr, for
different mixes and time series. The MOR was calculated for each individual specimen, as
well as the average value for each time series. Table 7.2 summarizes the average flexural
strength values obtained for each time series, and Table B. 1 of appendix B summarizes the
data observed for each individual specimen as well as the average value for each time
series. Plots were also obtained for the variation of MOR, fr, with time, comparing various
mixes.
• For mix series A containing 1% fibers by volume, the 50/50 mix outperformed all
others in terms of the MOR. The use of 50/50 fibers increased the 1-, 7-, and 28-day
flexural increases in strength for this mix at 7 and 28 days relative to the 1-day strength
were 10 and 15%, respectively.
• The use of 1% by volume of polypropylene fibers did not change the 1-day flexural
strength relative to the control mix. However, it did cause a slight increase in the 7- and
28-day strengths (17%) ( Fig. 7.28).
• Compared with the control mix, the following changes in fr were observed for the use
of 1% of polypropylene, 30/50 + polypropylene, 30/50, 30/50 + 50/50, and 50/50
fibers: (1) 0%, 0%, 45%, 55%, and 125% increases in the 1-day strength; (2) 18_,
28%, 51%, 135%, and 163% increases in the 7-day strength; and (3) 19%, 15%, 19%,
67%, and 111% increases in the 28-day strength (Fig. 7.28).
• A significant deterioration in the fiexural strength was observed for all time series of the
mix containing 2% by volume of polypropylene fibers (Fig. 7.29).
• The mixes containing 2% by volume of 30/50 and 30/50 + 50/50 fibers showed the
highest fiexural strength at 1, 7, and 28 days compared with all other series A mixes
(Fig. 7.29).
I01
180O
1600 .....____=_=/=....---
1400'.. f_-
1200"
"_,--10oo o _ -
800- -'=
600" &--"_-" ............ _.................
400".... "*'--" Control = PolvDroDvlenefibers
200- :" 30/50 • 30/50 + 50150a 50/50 J. Polypropylene+ 30/50
01 7 28
Time, days
Fig. 7.28 - Modulus of Rupture fr vs. Time for Different Mixes, (Vf=1% )
2000• _
1800 - __"_.r-""_ o
1600"
1400
em
(n 1200
Q" 1000=.--- 800
"r_''" - i-1
600"
400" ---a Polypropylenefibers.... ,,--- Control :- 30/50 + 50150
200o 30/50 - Polypropylene+ 30/50
! | !
1 7 28
Time, days
Fig. 7.29 - Modulus of Rupture fr vs. Time for Different Mixes, (Vf=2%)
102
Only typical curves were shown and discussed in this section. The remaining graphs,
including all parameters studied, are presented in appendix B, Figs. B.21 to B.29, and the
related conclusions are summarized in section 7.4.
7.3.4 Toughness Index
The purpose of this section is to summarize the analysis performed on all beams involving
the calculations of various toughness indices. The results are presented in tabulated (Table
7.2) and graphical forms. Toughness indices are calculated as a means of evaluating the
flexural toughness or energy absorption capacity of FRC in terms of the area under the load
versus deflection curve. The def'mition of toughness index is given in section 7.2. Two
methods of computation were used in this study. In one, the reference deflection is taken as
that of the unreinforced control mix. In the other, the reference deflection is the deflection
of first cracking of the specimens being tested (ASTM C 1018) [1].The toughness indicesare defined as follows:
• Is-co:the ratio of the area under the load versus deflection curve up to three times the
maximum deflection attained by the control mix, dco, divided by the area under the load
versus deflection curve up to dco
• I10-co: the ratio of the area under the load versus deflection curve up to 5.5 times the
maximum deflection attained by the control mix, _eo,divided by the area under the load
versus deflection curve up to _co
• IN-co: the ratio of the area under the load versus deflection curve up to 10.5 times the
maximum deflection attained by the control mix, _o, divided by the area under the load
versus deflection curve up to _co
° ISlst-CR: the ratio of the area under the load versus deflection curve up to three times
the first-crack deflection, 151stCR,divided by the area under the load versus deflection
curve up to _ilstCR in accordance with ASTM C 1018-89
° I101st-CR:the ratio of the area under the load versus deflection curve up to 5.5 times the
first-crack deflection, 151stCR,divided by the area under the load versus deflection curve
up to 81stCRin accordance with ASTM C 1018-89
103
• I201stCR:the ratio of the area under the itoad versus deflection curve up to 10.5 times
the f'trst-crack deflection, _ilstCR,divided by the area under the load versus deflection
curve up to _lstCR ill accordance with ASTM C 1018-89.
It should be noted that the toughness indices were calculated using the average load versus
deflection relationship of each time series. The following observations were made:
• In general, toughness indices calculated using as a reference the deflection at failure of
the control mix showed a consistent trend, wheras those calculated using the first
cracking load showed no consistent trend, since the onset of ftrst cracking may be quite
subjective.
• Iseoand I10co for all mixes steadily decreased with time up to day 28. However, the
IS-lstCR and I10-1stCRdid not show a consistent trend (Figs. 7.30 through 7.33 ).
• The addition of latex to the mixes with 1% 50/50 and 30/50 + 50/50 showed a
significant drop in the Is-co and Ilo-_ values up to day 7, thereafter slightly increasing
up to day 28 (Fig. 7.34 and 7.35). The modification of the polypropylene mix with
latex showed a steady decrease in the Is-co and I10-covalues (Fig. 7.36). All three
mixes showed no significant change in the IS-lstCR and I10-1stCRvalues.
• The addition of silica fume to the 50/50 mix led to a sharp drop in the I10-coup to day 7
(55%) and a milder drop up to day 28 (15%). IS-lstCR and I10-1stCRshowed no
significant change at any time. (Fig. 7.37).
• Fig. 7.38 shows a decreasing I20-cowith time for all mixes containing 1% by volume
of steel fibers (series A). Fig. 7.39 shows the variation of I20-1stCRfor the same
mixes. It can be observed here that the method for computing the toughness index,
based on the first cracking load, does not lead to a consistent trend.
• Fig. 7.40 shows the general trend of ductility loss with time for all series A mixes
containing 1% by volume of fibers and using Is-co. The polypropylene mix showed the
sharpest drop in Is-co compared with other mixes.
• Fig. 7.41 describes the same mixes as Fig. 7.40 except that the ductility is measured
using IS-lstCR. Again, unlike the Is-co, I5-1stCRshows no consistent trend for the
variation of ductility with time.
104
30Type of Fibers:
30/50 Hooked SteelVf = 1%
--,o-- 15-1stCR-- o 15-CO
. 20 _ --4=-- I10-1stCRx_- = 11O-CO"0
c 10
k-
0 i i ¢
1 7 28Time, days
Fig. 7.30 - Toughness Index Is and Iio vs. Time, 30/50 Steel Fibers, (Vf-l%)
60 Type of Fibers:30150 Hooked Steel
50 Vf = 2%
. --,o-- 15-1stCR
x" = 15-CO40'
•o --g-- ll0-1stCR: I10-CO
30'w
e-,,¢o= 20
o1-
10 • m-.......... -4c- ........ -8- ....... ,
i ! i
1 7 28Time, days
Fig. 7.31 - Toughness Index Is and Ilo vs. Time, 30/50 Steel Fibers, (Vf=2%)
105
40Type of Fibers:
50/50 Hooked SteelVf = 1%
" 30 _ -- .o-- 15-1stCR
" _ = 15-C0
x--4'-- I10-1stCR"o
= -- _ ; I10-C0
e,-c-
O 10 ........I'-
0 I 1 I
1 7 28Time, days
Fig. 7.32 - Toughness Index Is and llo vs. Time, 50/50 Steel Fibers, (Vf=l%)
20 Type of Fibers:112" Polypropylene
Vf = 1%
e-
gg
1 7 28Time, days
Fig. 7.33 - Toughness Index Is and I1o vs. Time, 1/2" Polypropylene Fibers, (Vf=1%)
106
70 Type of Fibers:50150 Hooked SteelIL
60 _ Vf = 1%,%
Chemical Addltlve: Latex,. 50 _ --.e-- 15-1stCR,; _ = 15-com _ I -- _ I ! I10-1stCR•o 40
_ 3offl
C
•_ 20
I-- 10 =..........mNmm O
0 I I I
1 7 28
Time, days
Fig. 7.34 - Toughness Index Is and Izo vs. Time, 50/50 Steel Fibers, Latex, (Vf-l%)
40Type of Fibers:
30150 Hooked Steel +50150 Hooked Steel
30 __- lY,o Chmlecal Addltlve:jLatex
xI l 40 I I 15"lstCR
"o = 15-C0--- 20 --a-- I10-1stCR_ COmWt-
_ 10-10 _ ....... _ oj,-
I I I
1 7 28Time, days
Fig. 7.35 - Toughness Index Is and Izovs. Time, 30/50 Steel + 50/50 Steel Fibers,Latex, (Vf=1%)
107
8B" IP ,111
Type of Fibers:7 1/2" Polypropylene
Vf = 1% --,o-- 15-1stCR.- Chemical Additive: Latex = 15-COx" 6 __.__L ----4=---- I10-1stCR=) - I10-C0
° 5
C,- 4
_ ¢ ,
°I- 3
i ! i
1 7 28
Time, days
Fig. 7.36 - Toughness Index Is and Ilo vs. Time, 1/2" Polypropylene Fibers,Latex, (Vf=l%)
60Type of Fibers:
____ 50150 Hooked Steel
50 Vf = 1%., Chemical Additive:- Silica Fume
X¢_ 40"O --,o-- 15-1stCR¢= = 15-C0
u_ 30 --4= -- I10-1stCR= I1O-CO
" 2001
oI-- 10 _" ......O-
0 ! i i
1 7 28
Time, days
Fig. 7.37 - Toughness Index I5and Ilo vs. Time, 50/50 Steel Fibers,Silica Fume, (Vf=1%)
108
70
o 30/50
60 %,. = 50/50-- 30/50 + 50/50
50 = Polypropylene + 30/50
o 40
o30
2O
10
! ! I
1 7 28
Time, days
Fig. 7.38 - Toughness Index I2o -co vs. Time for Different Mixes, (Vf=1%)
5O
= 30/50* 50/50
,. --- 30/50 + 50/50
,.,- 40 __30/50
o,
o 3O
-20
10 , , ,1 7 28
Time, days
Fig. 7.39 - Toughness Index I2o -lst-CR vs. Time for Different Mixes, (Vf=1%)
109
2O
--_' 30/50 1
50/50Polypropylene Fibers
15 % = 30/50 + 50/50 .. "_ " " Polypropylene + 30/50 c
fO 10 =
It}
-
! ! i
1 7 28
Time, days
Fig. 7.40 - Toughness Index I5 -co vs. Time for Different Mixes, (Vf=l%)
11:- " 30050
= " 50/50
I0 ._k = _- Polypropylene Fiberss
: Polypropylene + 300509' \_ • - 30/50+50'SO
e¢
o, 8g'J
7
6
5
i i j
1 7 28
Time, days
Fig. 7.41 - Toughness Index I5 -1st-ca v_ Time for Different Mixes, (Vf=l%)
110
• Fig. 7.42 shows the variation of I5-co with time for mix series A containing 2% by
volume of fibers. The figure suggests that although the 30/50 + 50/50 mix showed a
sharp loss of ductility at 7 days relative to 1 day, all other mixes showed no significant
change in I5-cowithtime.
From the above study, it can be generally concluded that the use of the area under the load-
deflection curve of the control mix, as opposed to using the area under the load-deflection
curve up to first cracking, leads to more rational and consistent results for ductility indices
[2,3,4,5, and 7].
Similar graphs were plotted and analyzed for all the other test series. They are included in
appendix B, Figs. B.30 to B.39. However, conclusions drawn from the test results aresummarized in section 7.4.
7.4 Conclusions
This section summarizes the main results of this part of the experirnental investigation
which dealt with the flexural properties of High Early Strength Fiber Reinforced Concrete
(HESFRC) subjected to static flexural loading. General conclusions are drawn from the
results obtained, and some recommendations with regard to optimal mixes for bending
properties are suggested.
The following conclusions regarding the response of all HESFRC composites in flexure
were arrived at:
1. The load versus deflection response of the mix containing 1% volume fraction of 50/50
fibers does not change significantly with time. However, the one-day flexural strength
of the composite was about twice that of the control mix.
2. For a volume fraction of fibers Vf = 1%, the use of 50/50 instead of 30/50 steel fibers
led to a 70% increase in the flexural strength.
3. Using 2% by volume of 30/50 fibers instead of 1% causes the flexural strength to
increase about twofold. It was not possible to properly mix 2% by volume of 50/50
fibers with the matrix specified for HESFRC mixes.
111
40
= 30/50
= PolypropyleneFibers30 _ - 30/50 + 50/50
o _" Polypropylene+ 30/50rj
2O
Iml
lO '0
! i !
1 7 28
Time, days
Fig. 7.42 - Toughness Index Is -co vs. Time for Different Mixes, (Vf=2%)
112
4. Using polypropylene fibers at very low volume fractions (i.e., Vf = 0.15%) does not
change the tensile properties of the composite when compared with the control mix,
wheras using polypropylene fibers at volume fractions as high as 2% will generaUy
result in a deterioration in the tensile properties, compared with the control mix. This
deterioration is primarily due to mixing difficulties that lead to an increase in entrapped
air. Further, the use of polypropylene fibers in HESFRC mixes did not lead to a
sufficient post cracking strength at seven and 28 days.
5. Mixes containing polypropylene fibers exhibited very low strain capacity before the
peak load in comparison with mixes containing steel fibers or a combination of
polypropylene and steel fibers.
6. In mixes containing 2% fibers by volume, the replacement of 1% of 30/50 hooked
steel fibers by an equivalent amount of polypropylene fibers led to lower flexural
strengths. However, replacing the same amount with 50/50 hooked steel fibers resulted
in a significant improvement in the tensile properties.
7. In mixes containing 2% fibers by volume, the use of 30/50 hooked steel fibers led to a
1- and 28-day flexural strengths about 4 times those given by the polypropylene fiber
mix.
8. Latex significantly improved the load versus deflection response in flexure and the
flexural strength with time (seven and 28 days) of all HESFRC mixes tested. The 28-
day flexural strength increased by 15 to 30% relative to plain FRC.
9. The addition of latex did not enhance the 1-day flexural strength. In fact, in the mix
containing 50/50 steel fibers, a reduction in the 1-day strength was observed when latex
was added.
10. The presence of silica fume in HESFRC mixes was observed to significantly enhance
the flexural response of the 50/50 fiber mix with time. The polypropylene and 30/50 +
50/50 fiber mixes showed an increase in the flexural strength up to day 7, and no
improvement thereafter.
11. In general, the addition of silica fume did not significantly change the 1-day fiexural
response of the 50/50, polypropylene, and hybrid 30/50 + 50/50 mixes (mix series C),
relative to the plain FRC mix.
113
12. No consistent trend was observed for lhe 28-day load-deflection response of mix series
C relative to the plain FRC mixes. Silica fume caused changes of +20%, -15%, and
+3% in the flexural strengths of the 50/50, polypropylene, and 30/50 + 50/50 mixes,
respectively, relative to the plain FRC mixes.
13. From the evaluation of toughness indic:es, it can be generally concluded that the use of
the area under the load-deflection curve of the control mix, as opposed to using the area
under the load-deflection curve up to tSrst cracking, leads to more rational and
consistent results of ductility indices [2,3,4,5, and 7].
14. For practical mixing limitations using steel fibers, a simple rule of thumb is to keep the
reinforcing index Vf 1/4 less than about 1.2, where Vf is the volume fraction of fibers
and 1/4is their aspect ratio (or length divided by diameter). Bending properties should
improve with an increase in the reinforcing index.
7.5 Recommendations
Table 7.2 summarizes the average key results obtained for all 17 HESFRC mixes tested. It
can be generally observed that mixes containing hooked steel fibers can be considered to
satisfy the requirements set forth by the SHRP advisory committee for HESFRC. Mixes
containing 1 or 2% of polypropylene fibers showed substantially lower high early flexural
strengths, as well as toughness indices.
The toughness index of HESFRC mixes should be computed using, as a comparison, a
similar plain concrete mix without fibers. The use of the area under the load-deflection
curve of the same FRC specimen up to first cracking, as suggested in ASTM C 1018,
instead of the control specimen, may lead to notable errors in the estimation of the
toughness index [2,3,4,5, and 7].
7.5.1 Recommendations Based or, Strength Criteria
Based on this experimental investigation, the following recommendations regarding the
flexural strength are proposed (Note that a summary of the average results is given in Table
7.2)
114
1. The optimal mix that gave the highest flexural strength at one day was the mix
containing 2% bv volume of 30/50 hooked steel fibers (A2%S3). Therefore, it is
recommended to use this mix for applications requiring high early tensile (bending)
strength.
2. Next in performance was the hybrid mix containing 2% by volume of 30/50 + 50/50
hooked steel fibers (A2%S3S5).
3. The tensile (bending) properties of the mix containing 1% by volume of 50/50 hooked
steel fibers were also considered very good, as shown in Table 7.2.
4. The use of polypropylene fibers alone in HESFRC mixes is not recommended, since
mixes containing polypropylene fibers showed lower strengths at early ages and post
cracking load-deflection response poorer than equivalent mixes with steel fibers.
However, hybrid mixes with steel and polypropylene fibers fared much better.
5. The use of latex in HESFRC composites is not desirable in applications for which high
early strength is sought. However, the tensile properties of HESFRC composites
containing latex significantly improved with time. Therefore, if the objective is to obtain
high-tensile, long-term strength, latex is recommended for use with mixes containing
1% by volume of 50/50 or 30/50 + 50/50 steel fibers. It should be observed that latex
is generally used to improve other properties, such as bonding between new and old
concrete in repair applications, and to improve durability. These very important
properties were not tested in this investigation. However, it is expected that they would
be improved in HESFRC mixes just as they would for plain concrete mixes.
6. The addition of silica fume does not significantly affect the 1-day flexural properties of
HESFRC composites. However, tensile (bending) properties are improved at later
ages.
7.5.2 Recommendations Based on Energy Absorption (Toughness) Criteria
It can be generally observed from the data that the toughness index decreases with time
(Table 7.2). Considering the toughness indices obtained using the control mix, it seems
very appropriate to set, in addition to the strength limit, a limit for the toughness indices 15,
I10, and I20 for all HESFRC mixes. First-hand recommendations may be as follows: an I5
larger than 5, an I10 larger than 10, and an I20 larger than 15. Since I20 could not be
115
obtained for some of the HESFRC mixes, only 15and I10will be considered. In applying
the above criteria, the following recommendations can be made with regard to the optimal
HESFRC mixes tested at one day:
1. The following mixes can be considered to have equal optimal energy absorption
properties: mix containing 2% of 30/50 fibers (A2%S3), hybrid mix containing 2% of
30/50 + 50/50 fibers (A2%S3S5), and the latex HES mix containing 1% of 50/50
fibers (B 1%S5).
2. Next in performance comes the hybrid latex and silica fume HESFRC mixes containing
1% of 30/50 + 50/50 fibers (B1%S3S5 and C1%$3S5, respectively). These mixes
showed toughness indices 50% lower than the optimal mixes described in 1.
3. All other HESFRC mixes containing either hooked steel fibers or a combination of
polypropylene and hooked steel fibers showed lower, but acceptable, energy
absorption properties.
4. The toughness indices of the HESFRC mixes containing polypropylene fibers were
lower than the limits set forth in this study. Therefore, if the objective is to obtain high
early energy absorption properties, the use of polypropylene fibers alone in HESFRCmixes is not recommended.
116
7.6 References
1. ASTM. Standard Test Method for Flexural Toughness and First-Crack Strength of
Fiber-Reinforced Concrete (Using Beam With Third-Point Loading) ASTM C1018-
89, vol. 04.02.
2. Johnston, C. D. "Definition.and Measurement of Flexural Toughness Parameters for
Fiber Reinforced Concrete" Cement, Concrete, and Aggregates, vol. 4, no. 2(1982),
pp. 53 - 60.
3. Johnston, C. D. "Precision of Flexural Strength and Toughness Parameters for Fiber
Reinforced Concrete" Cement, Concrete, and Aggregates, vol. 4, no. 2(1982), pp.
61 - 67.
4. Johnston, C. D. "Steel Fiber Reinforced and Plain Concrete: Factors Influencing
Flexural Strength Measurement" Journal of the American Concrete Institute, vol.
79, vo. 2(1982), pp. 131 - 138.
5. Johnston, C. D., and R. J. Gray "Flexural Toughness and First-Crack Strength of
Fiber-Reinforced Concrete," paper presented at the 3rd RILEM International
Symposium on Fiber Reinforced Cement Composites, Sheffield, July 1986.
6. Naaman, A. E., and F. M. Alkhairi Flexural and Splitting Tensile Properties of
High Early Strength Fiber Reinforced Concrete SHRP Project C-205, Department
of Civil Engineering, University of Michigan, Report No. UMCE 92-08, April
1992.
7. Ramakrishnan, V., G. Y. Wu, and G. HosaUi "Flexural Behavior And Toughness
of Fiber Reinforced Concretes," paper presented at the Transportation Research
Board 68th Annual Meeting, Washington, D.C., January 1989.
117
8
Splitting Tensile Tests
8.1 Experimental Program
Tensiletestsweresubdividedinto thr_ major groups(Table 8.1) to parallel the tests
undertakenin compressionand bending [2] : (1) seriesA, consisting of HESFRCmixes
having two volume fractionsof fibers (1 and 2%by volume of concrete), two types of
fibermaterials (hookedsteel fibersandpolypropylene fibers),and for the hooked fibers,
two lengths, 30 and 50 ram; (2) seriesB, consisting of HESFRCmixes containing 1%
fibersby volume and 10%latex solidsby weight of cement; and (3) series C, consisting of
HESFRCmixescontaining 1%fibersbyvolume and 10%microsilica (silica fume) by
weight of cement. Fig. 8.1 shows a flowchart summarizing the test program. Two types
of tests were conductedto studythe tensile propertiesof aUHESFRCmixes: the 1-day
splitting tensile strengthand the 1-daycompressivestrength.Specimen ID notation is
shown in Fig. 8.2.
8.2 Test Apparatus and Procedure
Fourstandardcylindrical4 x 8 in. test specimenswere prepared to determinethe 1-day
splittingand compressivestrengths. These were obtained directly from the load recorded
by the testing machine. The setup for the splitting tensile tests is shown in Figs. 8.3, and
the setup for the compression tests is described in Fig. 6.4.
Two ofthecylinderswerecappedtwoto three hoursbeforetestingby theuseofasulfur
compound.Thetworemainingcylinderswereusedforthesplittingtensiletests.According
totheASTM C 496-86procedureforthesplittingtensiletest,twopiecesofhardwood
119
Table 8.1. Number of Specimens Tested
Mix Series tFiber Fiber No of Cylinders TestedType Type Volume 4 x 8 in.
Fraction *fspt [ fcVf (%) Test Conducted at (days)
1 1
HES A Conu'ol 0 2 2HES A 30/50 1 2 2IdES A 30/50 2 2 2
A 50/50 1 2 2HES A PP 0.15 2 2HES A PP 1 2 2HES A PP 2 2 2HES A 30/50 + PP 1 2 2HES A 30/50 + PP 2 2 2HES A 30/50 + 50/50 1 2 2HES A 30/50 + 50/50 2 2 2
HES + LA B 50/50 1 2 2HES+ LA B PP 1 2 2HES + LA B 30/50 + 50/50 1 2 2IdES+ SF C 50/50 1 2 2HES + SF C PP 1 2 2
HES + SF C 30/50 + 50/50 1 2 2
Notes: fspt = splitting tensile test; fc = compressivestrengthtest;LA = latex; PP -- polypropylene;SF -- silica fume.
120
• / e_ 0 _.I_
.._ =
121
1D 48 fc 1
- Specimen Number (I, 2, or 3)I
- A = Average of all specimens
. S = Standard deviation
Y_xat.X
- fc - Compressive and elastic modulus
- fr = Flexural
- ft = Splitting tensile
_ize of Cylinder
48 =4 x8in.
612 = 6x 12 in.
Time of Testim,
- 1D = 1 day
- 3D = 3 days
- 7D = 7 days
-28D = 28 days
Fig. 8.2 - Specimen ID Code.
122
Fig. 8.3 - Set-up for Splitting Tensile Test
123
PHARDWOOD
Fig. 8.4 . Specimen Positioning for the Splitting Tensile Test
124
measuring 0.25 x 0.75 x 8 in. were placed 180° apart along the longitudinal axis of each
cylinder, as shown in Fig. 8.4. This was done to avoid any stress concentrations that
might result along the line of application of the load. Prior studies on split tensile
properties of FRC were also reviewed for additional information and knowledge [1,3, and
4].
The compressive and splitting tensile tests were performed simultaneously for each series
on a 600-kip-capacity Instron universal hydraulic testing machine. For each test, two
cylinders were te.stedup to failure. Only the nominal compressive and splitting tensile
strengths were recorded.
After completing the compressive tests, the bottom swivel head of the testing machine was
prevented from rotating to facilitate testing for the splitting tensile strength of the two
remaining cylinders. The longitudinal axis of each cylinder was placed at 90° to the loading
direction, with the two pieces of wood directly in contact with the upper and lower parts of
the swivel head. In both tests, the displacement-controlled method was used at a loading
rate of 0.001 in./sec.
The data were recorded by a data acquisition system and were then reduced by the
procedure described in chapter 6.
8.3 Data Analysis and Tests Results
This section discusses the results obtained from the splitting tensile and compressive
strength tests conducted at one day on all 17 HESFRC mixes. Table 8.2 summarizes the
average key results obtained. Tabulated values for each individual specimen can be found
in Table B. 1 of appendix B.
It can be generally observed from Table 8.2 that most mixes containing hooked steel fibers,
particularly with 2% volume content, can be considered to satisfy the requirements set forth
by the SHRP advisory committee for HESFRC. Mixes containing 1 or 2% by volume of
polypropylene fibers showed substantially lower compressive strengths.
Corresponding graphs are presented and commented on next.
125
Table 8.2. Average f'c, fr, and fspt Values for Each Time Series
Mix ID Specmmn :r fc fspt
ID (_si) (ksi) (psi)Control 1D.A 646.88 4.22 407.83Connml 713 A 600.0 ......
_onn_l _D=A 790.31 ......A1%S3 ilD A 937.5 3.26 746.04
,l s3 9os .:- --A1%S3 ?.SDA 937.5 .....A2%S3 ID.A 1545.0 5.83 1024.56_%S3 7D A 1866.56 .....
A2%S3 281_=A 1817.81 .....A.1%S5 1D.A 1451.25 4.79 880.33_,1%S5 7D A 1575.0 .....A1%S5 281_ A t668.75 ....
A. 15%P0.5 !D=A 537.19 4.16 460.36A. 15%P0.5 7DA 787.5 ......A.15%PO.5 28D A 843.8 ......
A 1%P0.5 IDA 64406 4.08 028.66
AI%P0.5 7D.A 701.25 .....
AI%P0.5 28DA 938.44 ......A2%P0.5 ID A 459.38 2.._2 .527.2
A2%P0.5 7D.A 619.69 ......A2%P0.5 28D A 632.81 ......
m
AI%S3S5 1D_A 999.38 4 58 648.56A1%S3S5 7D A 1410.94 .....
A1%S3S5 18I_A 1321.88 .....A2%S3S5 ID.A 1517.81 5.23 1045.45A2%S3S5 ID.A 1757.81 .....
A2%S3S5 ?.SDA 1912.5 ......AI%S3PO.5 liD A 647.81 4.22 ._65.99
AI%S3PO.5 7D_A 770.63 ......
A1%S3P0.5 28D A 909,.$$ .....g2%S 3P0.5 1DA 714.38 3.78 577.93A2%S3PO.5 7D A 934.69 .....
A2%S3P0.5 28D=A 1054.69 .....B1%S5 IDA 1007.81 2.98 666.46Bi%s5 7D A 1378.13 ......
B1%S5 28D A 1921.88 ......BI%PO.5 ID A 57._.63 2.55 328.26
81%P0.5 7D_A 63"7.5 ......
31%P0.5 ?.SD_A 871.88 .....31%S3S5 ID.A 1013.4.4 3.58 507.31B1%S_55 /D.A 1406.25 ......81%S3S5 28D A 1753.13 .....
"1 I
C1%$5 ID_A 1228.13 5.15 859.44
_1%S5 7D A 1449.38 ......C1%$5 ?.SDA 1978.13 .....CI%P0.5 ID.A 553.13 3.7 442.65 •C1%P0.5 7D.A 648.75 .....
C1%P0.5 _D=A 787.5 ......CI%$3S5 ID A 984.38 4.72 802.74
C1%$3S5 ID A 1425.0 ......
C1%$3S5 28D=A 1350.0 .....
126
Fig. 8.5 describes the variation of the MOR, fr, versus the square root of the compressive
strength, f_f-_c• These are the 1-day test results described in chapter 7, Table 7.2. As
observed for plain concrete, a strong correlation exists [3, and 4]. However the best-fit
equation derived from the data is quite different from that used for plain concrete, namely:
fr = -1030. + 30.55 _ (psi) (8.1)
The coefficient of correlation is equal to 0.618, and the conditional standard deviation is
288 psi. The two lines shown in Fig. 8.5 are plus or minus one standard deviation away
from the mean line and bound 68% of the data.
Fig. 8.6 describes the variation of the splitting tensile strength at one day, fspt, versus the
square root of the compressive strength, _ The regression line for the data is given by
the following equation:
fspt = - 611. + 19.73. _ (psi) (8.2)
The conditional standard deviation of the data is 219 psi, and the coefficient of correlation
is 0.646. The two lines plotted in Fig. 8.6 are plus or minus one standard deviation away
from the mean and bound 68% of the data.
Although these two equations for fr and fspt are different from the relations usually
recommended in codes of practice (AASHTO, ACI), it is interesting to note that the ratio
between fr and fspt is about 3/2, as expected.
The results comparing the splitting tensile and compressive strengths for different test
series and different parameters are plotted using bar charts.
• The 50/50 mix of series A containing 1% by volume of fibers showed the highest
splitting tensile strength (fspt) at 1 day, giving 2.16 times the strength of the control
mix. (Note that fspt for the control mix = 407 psi; f'e = 4.22 ksi). Next in performance
was the 30/50 mix, giving a strength 1.84 times that of the control mix. The remaining
mixes of series A gave splitting tensile strengths equal to 1.5 times that of the control
mix (Fig. 8.7).
• Fig. 8.8 shows that the 30/50 and 30/50 + 50/50 mixes containing 2% by volume of
fibers give the highest splitting tensile strengths compared with all other mixes in series
A (1,000 psi compared to 407 psi for the control mix). The mixes containing
polypropylene fibers led to the lowest strengths (450 psi).
127
2000
• Control• A1%S3
O. • A2%S3
b. • A1%S5 ---*"_
"- 1500 • A0.15%P0.5 _e = '
" A1%P0.5= • A2%P05eL • A1%S3S5=3 /a 6/o_" 1000 • A2%S3S5 "/"_ • •m /
+ Al%S3P0.5 "7O • A2%S3P0.5
= • B1%S5 ./. • __2 • Bl%P05 f " ]/T-s 500 •
• B1%S3S5O
o C1°/oS5• C1%P05= C1%$3S5
0 | ! = = -
0 20 40 60 80
f',/_-, (pill o.s )
Fig. 8.5 - Modulus of Rupture fr vs. _cforDifferent Mixes.
-_" 12oo
• Control
=. 1000 • A1°/,,.%3
._- •• A1%S5• A0.15%P0.5
J_., 800 • A1%P0.5 / •/.
=- * A1%S3S5" 600
(0 , A2%S3S5 ///_ 1=.'/+ AltY=S3P0.5
• /= • A2%S3P0.5o_¢ 400' • B1%S5
°I- " B1%P05 •
• B1%S3S5
¢ 200' O C1o/_5,_ • C1%P05m
_. = C1%$3S5
0 20 40 60 80
, (pill o.=)
Fig. 8.6 - Splitting Tensile Strength fspt vs._c for Different Mixes
128
1000
8OO
0
u.¢) e5 m
lk
Fig. 8.7 - Splitting Tensile Strength fspt for Different Mixes, I Day, (Vf=1%)1200
8O0
0
0 _
a,
Fig. 8.8- Splitting Tensile Strength fspt for Different Mixes, 1 Day, (Vf=2%)
129
* Fig. 8.9 compares all three mixes of series B (latex modified) for 1% fiber volume
fraction tested at 1 day. In comparing Figs. 8.7 and 8.9, it can be observed that the
modification of the 50/50, polypropylene, and 30/50 + 50/50 mixes with latex causes
a 30, 50, and 20% reduction in fspt relative to the plain FRC mixes (i.e., series A
mixes).
• Fig. 8.10 shows mix series C containing silica fume. When Fig. 8.10 is compared
with Fig. 8.7, it is observed that silica fume has little effect on changing the splitting
tensile strength when compared with plain FRC.
• Except for the mix containing 1% by volume of 30/50 fibers, Fig. 8.11 clearly shows
that mix series A containing 1% by volume of fibers achieves a compressive strength
in the range of 4 to 5 ksi. The requirement of achieving a minimum compressive
strength of 5 ksi or greater at 24 hours was satisfied for mixes 30/50 and 30/50 +
50/50 containing 2% by volume of fibers. However, mixes containing 2% by volume
of polypropylene fibers or 30/50 + polypropylene fibers did not satisfy this
requirement, as shown in Fig. 8.12.
• Fig. 8.13 shows that the use of latex decreases the 1-day compressive strength of the
50/50, polypropylene, and 30/50 + 50/50 mixes compared with plain FRC (Fig. 8.7),
by 40, 37, and 22%, respectively.
• Figs. 8.14 show that silica fume does not affect the 1-day compressive strength of all
mixes in series C (Fig. 8.7).
8.4 Conclusions
The following conclusions regarding the response of all HESFRC composites subjected
to splitting tensile stresses were arrived at:
1. The observed splitting tensile strength, fspt. of HESFRC mixes showed a good
correlation with the square root of the compressive strength, f'c, as suggested for
plain concrete.
2. Among all mixes of series A containing 1% fibers by volume, the mix with the 50/50
hooked steel fibers led to the highest splitting tensile strength, fspt, about 2.2 times that
130
8OO
6OO
"_es 4OO
,q
0
to
g
a.
Fig. 8.9 - Splitting Tensile Strength fspt for Different Mixes, 1 Day,Latex, (Vf=l%)
W 4_'
0
g.
Fig. 8.10 - Splitting Tensile Strength fspt for Different Mixes, 1 Day,Silica Fume, (Vf-l%)
131
3
_e
2
0
f_ t_ to
_o
ea.
Fig. 8.11 - Compressive Strength f'c for Different Mixes, 1 Day, (Vf=l%)6
0
o -
Fig. 8.12 - Compressive Strength f'c for Different Mixes, 1 Day, (Vf=2%)
132
3
"g 2
o
1
tt_
SL
Fig. 8.13 - Compressive Strength rc for Different Mixes, I Day,Latex, (Vf;1%)
$
5'
4,
"_ 3,
d
2"
1
Ki a
!
g
Fig. 8.14 - Compressive Strength f'c for Different Mixes, 1 Day,Silica Fume, (Vf-l%)
133
of the control mix. Next in performance was the mix with the 30/50 hooked steel
fibers, which had an fsptvalue about twice that of the control mix.
3. For the mixes of series A containing 2% fibers by volume, the mixes with the 30/50
and 30/50 + 50/50 hooked steel fibers gave the highest values for fsptamong all mixes;about 2.5 times that of the control mix.
4. The addition of latex led to a decrease of about 25% in the 1-day splitting tensile
strengthfor the mixes with 50/50 and 30/50 + 50/50 fibers and almost 50% in the mix
containingpolypropylene fibers, when compared with the mix without latex. In the
case of polypropylene fibers, the strength was even lower than that of plain concretewithout fibers or latex.
5. The addition of silica fume did not lead to any consistent trend for the mixes of series C
relative to the plain FRC mixes of series A. However, increases of 115 and 100% in
the 1-day splitting tensile strength were observed for the mixes with the 50/50 and
30/50 + 50/50 fibers, respectively, relative to the control plain concrete mix. The mix
with polypropylene fibers and silica fume fared less well than the mix without silicafume.
8.5 Recommendations
Based on this experimental investigation, the followingrecommendationsregardingthe
splittingtensile and compressive strengths areproposed. These recommendationsare
strictlybased on strength criteria. Note that a summary of the results is given in Table
8.2).
1. The optimal mix, which gave the highest splitting tensile and compressivestrengths at I
day, was the mix containing 2% by volume of 30/50 hooked steel fibers (A2%S3).
Therefore, this mix is recommended foxapplicationsrequiting high early tensile
strength.
2. Next in performance was the hybrid mix containing 2% by volume of 30/50 + 50/50
hooked steel fibers (A2%S3S5).
3. The tensile properties of the mix containing 1% by volume of 50/50 hooked steel fibers
were also considered very good, as shown in Table 8.2.
134
4. The useofpolypropylcncfibersaloneinFIESFRCmixesisnotrecommended,since
mixescontainingpolypropylcncfibersshowedlowerstrengthsatearlyages.However,
hybridmixeswithsteelandpolypropylcnefibersfaredmuch better.
5. The use of latex in HESFRC composites is not desirable in applications for which high
early strength is sought. However, the tensile properties of HESFRC composites
containinglatexsignificantlyimprovedwithtime.Therefore,fftheobjectiveistoobtain
high-tensile,long-termstrength,latexisrecommendedforusewithmixescontaining
i% byvolumeof50/50or30/50+ 50/50steelfibers.Itshouldbeobservedthatlatex
isgenerallyusedtoimproveotherproperties,suchasbondingbetweennew andold
concreteinrepairapplications,anddurability.Theseveryimportantpropertieswere
nottestedinthisinvestigation.However,itisexpectedthattheywouldbeimprovedin
HESFRC mixesjustastheywouldforplainconcretemixes.
6. Theadditionofsilicafumedoesnotsignificantlyaffectthel-daytensilepropertiesof
HESFRC composites.However,tensileproperdcsarcimprovedatlaterages.
135
8.6 References
1. ACI Committee 544. Measurement of Properties of Fiber Reinforced Concrete. ACI
Material Journal, 85, no. 6, Nov - l')ec 1988, pp 583 - 593.
2. Naaman, A. E., and F. M. Alkhairi Flexural and Splitting Tensile Properties of High
Early Strength Fiber Reinforced Concrete Depaiiaiient of Civil Engineering,
University of Michigan. Report No. UMCE 92-08. April 1992.
3. Nanni, A. "Splitting-Tension Test for Fiber Reinforced Concrete" ACI Material
Journal, 85, no. 4, July - Aug 1988, pp 229 - 233.
4. Potrzebowski, J. "The Splitting Test Applied to Steel Fibre Reinforced Concrete"
International Journal of Cement Composites and Lightweight Concrete, 5, no. I,
(Feb 1983), pp 49 - 53.
136
9
Fatigue Tests
9.1 Experimental Program
This part of the experimental program addresses the flexural fatigue testing of HESFRC beam
specimens under different load ranges. Because fatigue testing is extremely time consuming, it
was decided to limit the fatigue-testing program to only two mixes that gave best properties in
static compression, bending, and split tension (chapters 6, 7, and 8) and satisfied as well the
criterion for HESFRC set forth by the project advisory group.
The two mixes selected are described in chapter 4, A2%S3 and the A2%S3S5; that is, they are
made with concrete mix A, and contain 2% by volume of hooked steel fibers. The first mix
used the Dramix 30/50 (length = 30 mm; diameter - 0.5 mm; aspect ratio = 60) fibers, wheras
the second mix (hybrid mix) used an equal amount of Dramix 30/50 and Dramix 50/50 (length
= 50 mm ; diameter = 0.5 mm; aspect ratio = 100) fibers.
A total of 24 flexural specimens (numbered 1 to 24 for easy identification) were tested. Ten
control specimens were tested under static flexuml loading, and 14 specimens were tested
under fatigue loading.
For each mix, three different target load ranges were applied: 10 - 70%, 10 - 80%, and 10 -
90% of the ultimate flexural capacity, as obtained from the corresponding control static test.
The experimental program is described in Fig. 9.1.
137
I ExperimentalProgram I
+J HES- High EarlyStrength I
Volume Fraction =2%
+Hooked Steel Fibers Hooked Steel Fibers
I I
II ,°,.-.°,_I
Fig. 9.1 - Experimental Program for Fiexural Fatigue
138
The specimens were 16 in. long with a square cross section of 4 x 4 in. Third-point loading at
a clear span of 12 in. according to ASTM C 1018, was used, in a manner similar to that
described in Chapter 7.
9.2 Test Apparatus and Procedure
All flexural tests were performed in a 22-Kip capacity MTS hydraulic testing machine, Model
810 (Fig. 9.2). Three types of measurements were recorded for each beam: (1) the load from
the load cell of the testing machine, (2) the vertical deflection at the third points, and (3) the
bottom tensile elongation measured over a 4 in. gauge length between the load application
points. The vertical deflection was measured by two LVDT s placed at the third points on
opposite sides of the test beam. The bottom tensile elongation (also described here as strain
capacity) was obtained by one LVDT placed under the specimen along its plane of symmetry
and attached to a special aluminum frame, which in turn was fixed to the specimen third points
(Fig. 9.3). All measurements were recorded via a data acquisition system controlled by a
computer.
Before fatigue testing, all specimens were subjected to a nondestructive test to determine their
dynamic elastic modulus. The resonant frequency method (ASTM C 215-60) was used. The
prismatic specimens were subjected to flexural vibration, and the resonance frequencies of the
fundamental mode were recorded. These values were then used to determine the dynamic
modulus according to the expression provided in the standard. Values of dynamic modulus for
all specimens tested are summarized in Table 9.1. It was assumed that such values may
provide an additional measure of the prediction of the strength of the fatigue specimen, and
thus a possible correction to the cyclic load range applied.
The control static flexural tests were performed under displacement control. Measurements of
the load, deflections at the third points, and tensile elongation at the bottom fiber were
recorded, and the ultimate flexural capacity was obtained.
The fatigue tests were performed under load control. Each specimen was first subjected to three
slow cycles between the minimum and maximum load, to record the initial hysteresis loops
and stabilize the specimen. Then the specimen was subjected to a sinusoidal wave cyclic
fatigue loading with a frequency that, depending on the load range and expected fatigue life
from prior studies [1,2, and 3], varied between 1 and 5 hertz. The fatigue test was interrupted
periodically at a selected number of cycles to record, at a slow rate, an entire hysteresis loop
139
;,
Fig. 9.2 - Testing Machine Used in Flexural Fatigue Tests
140
Fig. 9.3 - Instrumentation and Test Set-up for Flexural Fatigue Tests
141
C
[.., [., r_ a,a, ELI.....n
m
_,_ • ,,._ t,,q t,_ .,_1- tr_ ,_ t,._ _ _.,_ _ _"_ t"q ¢_ "_ _r_ '_l_t'_ _ _'_ _ '_''_ ¢'q
142
between the minimum and the maximum load. The hysteresis loops were obtained for the load
versus third-point deflection and the load versus tensile elongation (or equivalently the strain
capacity) at the bottom fiber.
It should be noted that for the load ranges of 10 to 80% and 10 to 90%, two to three visible
cracks in the constant moment region were observed during the initial three static cycles. For
the specimens with the 10% to 70% loading range, no visible cracks could be detected with the
naked eye during the first three cycles. However, all specimens showed visible cracks (two to
three, not all the way through from both sides) during the first few thousand cycles
(ascertained during the recording of the hysteretic response with a 5x hand-held magnifier).
Since the specimens at the 10 to 70% loading range all showed fatigue life ranging from 105 to
more than 5 x 106 cycles, it can be stated that all specimens tested in this program were
effectively precracked before cyclic loading. This is an essential characteristic of the tests
undertaken here, when compared with previous studies on fiber-reinforced concrete.
The specimens were subjected to a constant load range fatigue loading until failure or 5 million
cycles, whichever occurred first. The two specimens that survived 5 million cycles were then
subjected to a static bending test up to failure.
Photographs of typical specimens that failed under fatigue loading are shown in Figs. 9.4 and
9.5 for mixes A2%S3 and A2%S3S5, respectively. As observed for all specimens, one major
crack (out of two to three visible ones) propagated in the constant moment region until final
failure of the specimen occurred.
9.3 Data Analysis and Test Results
The data recorded from the experiments were plotted in several ways, which include load
versus deflection curves and load versus strain capacity curves under both static or cyclic
loading and increases in deflection or strain capacity with the number of cycles of loading.
Some of these graphs are shown in the following sections, and the remainder can be found in
appendix C.
Table 9.1 summarizes the results of MOR obtained from the static load-deflection tests, and the
dynamic modulus obtainedfrom the dynamic modulus tests. The static MOR was used as a
reference value, based on which the load range for the fatigue test was determined for each
series. Table 9.2 summarizes, for each fatigue specimen tested, information on the load range,
143
Fig. 9.4 - Specimen #10 After Fatigue Failure, Mix A2%S3, Load Range 10%-70%
Fig. 9.5 - Specimen #15 After Fatigue Failure, Mix A2%S3S5, Load Range 10%-90%
144
°_
L_
•It. ,K-
o
ooo_ooo I '_ _ °° °°'_ _ _'_ _ _ _1__ _
#, _ eee _iT!eeeeeeee_
_ _ °O_ • eq _ _r_ o_ o_ _ _ _ _ _" °° _ _'_ _
145
number of cycles to failure, and, for the two specimens that survived 5 million cycles, the
MOR obtained from a static test to failure after fatigue loading.
The main highlights of the results are described next.
9.3.1 Dynamic Modulus of Elasticity
The main reason for running the dynamic modulus tests was to provide some correlation
between the MOR and the dynamic modulus, thus allowing for an additional method to predict
the MOR of the fatigue specimen: This should provide a means to introduce a possible
correction in the cyclic load range applied or to better explain certain results.
A comparison between the flexural strength (MOR) and the dynamic modulus data was carried
out for the specimens tested under static loading. The trend observed is illustrated in Fig. 9.6.
A power curve was fitted, leading to the following relation between the dynamic modulus,
Edyn, and the MOR, fr:
Edyn = 874,000. fr0.228 (psi) (9.1)
with a coefficient of correlation of 0.85. The above relationship was tried, as a second
alternative, to adjust stress ranges in the fatigue tests; however, the corresponding S-N diagram
showed a poorer correlation than obtained with the target stress ranges (first alternative):
Consequently, the second alternative was :notpursued further.
9.3.2 Fatigue Life and Endurance Limit
The fatigue life of a specimen is defined as the number of cycles to failure at the given loading
range. A large scatter is usually observed in fatigue life, even in the most carefully planned
tests. This is because a small error in the estimate of the ultimate strength induces an error in
the load range, which in turn can have an enormous effect on the number of cycles to failure.
Because of the limited scope of this study, only two to three specimens were tested under every
loading range. Results are presented in Table 9.2. In the table, the target load ranges based on
the flexural strength of the control test are shown in percent.
146
It can be observed from Table 9.2 that the specimens subjected to a loading range between
10 and 90% of the ultimate strength had a very low fatigue life. A major crack was always
observed in the first cycle, and with further cycling, it would propagate rapidly towards the
compression zone of the specimen, leading to its final collapse. The two specimens of
series A2%S3 sustained 9 and 23 cycles, respectively, and the two specimens of series
A2%S3S5 sustained only 2 and 4 cycles.
The specimens subjected to the 10 to 80% loading range sustained the following numbers
of cycles to failure: 3,679 and 3,900 cycles for the specimens of series A2%S3, and 8,964
and 15,000 cycles for the specimens of series A2%S3S5. Thus, on the average, series
A2%S3S5 sustained at least three times the number of cycles to failure resisted by series
A2%S3. The difference between the two may be attributed to the presence of longer fibers
in series A2%S3S5 (that is 50 mm versus 30 ram). However, the difference between the
two series may also seem insignificant when the data are plotted on a log scale.
For the loading range of 10 to 70%, three specimens were tested for each series. Five out of
the 6 specimens sustained more than 1.9 x 106 cycles, and one specimen of each series had
not failed after 5 million cycles. For these specimens, cyclic loading was stopped, and a
monotonic loading test to failure was carded out. The corresponding MOR was larger than
that of the control specimen, confirming a previously noted result that prior cycling may
lead to an improvement in strength [1,2, and 3]. The relatively large variability observed in
the tests at this range of loading indicates the endurance limit of the material is probably
being approached.
The maximum load as a percentage of the ultimate load is plotted versus the logarithm of
the number of cycles to failure in Fig 9.7 for all specimens, and a least-square-fit line is
derived. It can be observed that an endurance of about 68% of ultimate load may be
considered for 5 x 106 cycles.
9.3.3. Fatigue Life and Endurance Limit: Comparison with Other
Investigations
An extensive investigation on the fatigue life of FRC was carded out by Ramakrishnan et al. [1
to 3]. Several particular aspects of their investigation are pointed out next because of
differences with the present study: (1) the load ranges selected for the study were determined
with respect to the reference plain concrete mix without fibers; (2) the frequency of cyclic
147
5.5 1 06 .... E ................ i ....
C
>" 06 ..................2................................................• ........-....................•_ 5.1 1 .................
LLi ; • . • i ;
N 4.7 1 06 ...................................................
"0 ,/_ Edyn I _ D.2280 873890 _ fr
._o 06 ............................oo.....i :E 4.2 1 ....................'...........................................................:
C :
t_ 3.8 106 .................. _'''' ! ....
500.00 1500.00 2500.00 3500.00
Modulus of Rupture f (psi)r
Fig. 9.6 - Modulus of Rupture versus Dynamic Modulus
1 0 0 % ........1 ....... ! ........y ............... 'T ........T ........ l .......Minimum Loadi at10% of: Ultimate
m .-.. 90 % _.":'.'.'.'.'.'.'_-e................................................................... �.............................
"0 "_ = 93. -- .68 I g (N)
E o 70%
60% ..........................................................._..............i...............-...............,.............Specimens that
" " i
!didn'ti fall........I ........1 ....... ; ........I ........1 ....... I ,
50% ........ ' '"'"1 00 1 02 1 04 1 06 1 08
Cycles to Failure Nf
Fig. 9.7 - Number of Cycles to Failure versus Maximum Applied Load
148
loading was 20 hertz, a value considered too high to maintain an accurate load range and to
minimize the effects of inertia; and (3) the specimens were not precracked.
Ramakrishnan et al. concluded that for specimens reinforced with hooked-end steel fibers at
volume fractions of 0.5 and 0.8% with aspect ratios of 75 and 100, the maximum absolute
fatigue load under which the specimens could withstand 2 million cycles without failure was
2.0 to 2.5 times that of corresponding specimens with a plain mix with no fibers. In reference,
similar results were obtained for the absolute value of the fatigue load in specimens reinforced
with hooked-erA fibers with an aspect ratio of 100 at a volume fraction of 1%. Such results
are predictable, since the reference mix was taken as the concrete without fibers. In many
cases, the presence of fibers leads to a significant increase in the MOR. Indeed, referring for
instance to Table 7.2, it can be observed that the average MOR of the control mix without
fibers is 690 psi. On the other hand, the MOR of the same mix with 2% fibers (Table 9.1)
exceeds 1,265 psi in all cases. In the present investigation, the reference MOR (or flexural
strength) for adjusting fatigue load ranges for a given specimen was taken as that of the sister
specimen of the same mix with fibers tested under static loading.
9.3.4 Hysteretic Load versus Deflection Response
Hysteresis loops were recorded at various stages of the fatigue life of each specimens. Typical
examples are shown in Figs. 9.8 and 9.9, and additional information can be found in appendix
C.
The area enclosed by the load versus deflection hysteresis loop describes the amount of damage
done to the specimen during any recorded cycle. The hysteresis 10op allows us to extract the
values of deflections at Pmin and Pmaxand the permanent (non recoverable) deflection at any
cycle. Furthermore, the variation of the deflection between the minimum and maximum loads
gives a good indication of the loss of stiffness of the specimen due to fatigue loading.
In the specimens subjected to the 10 to 90% loading range (Figs. 9.8 and 9.11), the material
degradation is clearly illustrated by the large area enclosed by every loop and the resulting small
number of cycles to failure.
In the specimens subjected to the 10 to 80% and 10 to 70% loading ranges, the hysteresis
loops had a larger area at the initial cycles, followed by a stabilization period during which the
loops remained almost constant; then, closer to the fatigue life of the specimen, the area
149
12.00 .... I ........ ' ' ' I ....Spec #16 iA2%S3S5
10.00 ..............................................................................................i.......................- Fatigue LoaOing
: Range: i 10%-_cYC' les
) iiiiiiii!.......................g ..oo -.... i600
O4OOoo....................o oo _._l_,_ i _ _ .
0.000 0.010 0.020 0.030 0.040 0.050
Deflection (in)
Fig. 9.8 - Load versus Deflection Hysteretic Response of Specimen #16 underFatigue Loading
14.00 . , , , , , , j , , , _ , , ,Spec #20
1 2.0 0 -A2.%S3S5 .................... ! .......... _.......................Fatigue Loading
10. 0 0 _.Range: ......:1"0"%'80"?/'_"0Dff"8;;81_'_.......;...........................
"-" 8.00 ............... - ...........................
oooo..........Z......:II ........I
2.004.00 __ __ :::i'_"_'_'_"-. ....• 6000 cyclps0.00 , , , I , , , . , , , , , ,
0.000 0.013 0.025 0.038 0.050
Deflection (in)
Fig. 9.9 - Load versus Deflection Hysteretic Response of Specimen #20 underFatigue Loading
150
enclosed by the hysteresis loop increased again. This is clearly shown in Fig. 9.10 and 9.11.
Also observed in these figures is the relatively large permanent deflection developed with
cyclic loading.
Other important results of the fatigue tests are the increase in the p_mianent deflection at the
minimum and maximum applied load levels (Pminand Pmax) and the increase in the difference
of deflection (AS) between the minimum and maximum loads with the number of loading
cycles. Typical results are illustrated in Figs 9.12 to 9.13, and additional figures can be found
in appendix C.
The two specimens that did not fail under fatigue loading, specimens 9 (A2%S3) and 17
(A2%S3S5), showed different behaviors. Specimen 9 showed a period of constant permanent
deformations until about 2 million cycles, after which there was a substantial increase in the
permanent deformation until about 3 million cycles, followed by another period of constant
increase until the fatigue tests were interrupted at 5.276 million cycles. Specimen 17 (Fig.
9.13) showed a period of constant permanent deformation until the interruption of the fatigue
test at 5 million cycles. The post fatigue static load versus deflection curves for these two
specimens were similar to the static bending tests described in chapter 7 (Fig. 9.14). As
observed in previous investigations [1], the MOR obtained after fatigue is higher than that
before fatigue loading.
9.3.5 Load versus Tensile Strain Capacity
The average tensile strain in the constant moment region is related to the average crack width
observed. This is because the elastic tensile strains, being on the order of 2 x 104, can be
neglected. Most specimens had one to three visible cracks along the constant moment region.
Typical variations of the average tensile strain in the constant moment region at the minimum
and maximum applied load levels (Pminand Pmax)and the tensile strain difference (Ae)
between the minimum and maximum loads are plotted against the number of cycles in Figs.
9.15 and 9.16 for some of the specimens that failed under fatigue loading. A trend similar to
what was observed for deflection is noted; namely, a larger rate of increase in the early cycles,
followed by a period of stabilization with a constant rate of increase up to about 90 to 95% of
fatigue life, then again a higher rate of increase leading to failure.
151
12.00 .... i , _-- ..... z .... ....
; Spec #18 t.................2 A2%S3S5
1o.oo '!.......................................i__;ig_;£o;_ing........."3000 cyc!es Range: 10..=/=-70%
="8.oo -_..._y._o.._----t-1-11.............i................._1---"'-
o i"J 4.00 ............
2.00 ! _]Sf = ;9_09-42cycles [ r0.00 ................
0.000 0.010 0.020 0.030 0.040 0.050
Deflection (in)
Fig. 9.10 - Load versus Deflection Hysteretie Response of Specimen #18 underFatigue Loading
0.050 ' ' ' i ............Spec #21A2%S3S5
... 0.040 -Fatlgu_toacllng ...................i......................;.......................
._ Range:_ 10% to 80% i :
° o ......................................9
m _8
0 0.010 ..........-' -- .......T "_ ? ........................: iPmin,' • !lNf= 8964J
0.000 ,,, I, _, i,,, i,, _ , , ,0 2000 4000 6000 8000 10000
Number of Cycles
Fig. 9.11 - Variation of Deflection versus Number of Cycles for Specimen #21
152
• , i _ 1 1 1 i - 1 1 _ i i | 1 i
0 050 I- Spec #18
A2%S3S5 T.... O. 040 -"F_i'ti_'ii6"E'6&i_li_'iij........... i......................i...............¢= Range:i lO% to_70% i i /
- i i I..--t,C;.030 .........................................................................................
.o_ !o O 020 ...................... _"-':........=": :
,.--'=®" _.a O.OLO
A6 IINf = 19109420.000''' ' ' ' ' ' ' ' ' " ' ' ' ' ' '
0 800000 1600000
Number of Cycles
Fig. 9.12 - Variation of Deflection versus Number of Cycles for Specimen #18
0,080 _ .... i ................Spec _17
O. 070 F-_,2%"S'._"_'5...............-:..................._.....................[.......................
o.o6o _F-.-._a-t..!g.u,,._..--.L....°.._-_!.ng.....................i.......................i........................-: _Targetl Range:i 10%-70..=/o
0.050
.2 0,040dineOm 0.030i
0.020
0.010
0.0000 2000000 4000000
Number of Cycles
Fig. 9.13 - Variation of Deflection versus Number of Cycles for Specimen #17
153
20.00 .... I ........ I ........Spec #17A2%S31S5 i
16.oo -Zi-/,;_-'_'_x-{i_e-(_;_;ie-_-ai-1-6;_'."_"i_-;)_.....................
_,,12.00 ....
"omO 8.00 --..I
,ooFl0.00
0.00 0.10 0.20 0.30 0.40 0.50
Deflection (in)
Fig. 9.14 - Load Versus Deflection Response after Fatigue Loading for
Specimen # 17
0.020 , . , j ............
Spe¢ :#21A2%S2S3
0.01 6 --FiiJig__"E_ii_ ........................................................................i- Range,, 10% t(_ 80%
¢: 0 012 ....................................................................................................................
:._-ooo_...................-......................._........................i-,_-__..............
0.004 I_1 ...........0.000 : ' ' _ I , , , I , , , ] , , , I , , ,
0 2000 4000 6000 8000 I 0000
Number of Cycles
Fig.9.15- Variation of Strain versus Number of Cyclesfor Specimen #21
154
0.010 ' ' ' i ' ' ' I ............
Spec" #10A2%S3
0.0 0 8 --F_rti__E6_i_Iifi_..................._................................
.¢ Range: 10% to
.E o.oo6 ...........................................................................................
_:ooo,° ......................_E0.002 ..........
0.000 ,,, I,,, I,,, I,,, _ ,,, ] , , ,0 40000 80000 120000
Number of Cycles
Fig. 9.16 - Variation of Strain versus Number of Cycles for Specimen #10
155
9.4 Conclusions
1. Specimens reinforced with hooked-end steel fibers at volume fractions of 2% showed
average fatigue lives of the order of 10 c_,cles for loads ranging between 10 and 90% of
their static strength, 8,000 cycles for loads ranging between 10 and 80%, and more than
2.7 x 106 cycles for loads ranging between 10 and 70%. These values hold, assuming the
specimens are cracked. Substantially lar_er values can be achieved with uncracked
specimens.
2. From the limited number of tests undertaken in this study, the derived S-N curve in
bending of HESFRC with 2% by volume of hooked steel fibers is given by
S = 93 - 3.68 log(N 0 (9.2)
where S is the maximum cyclic load as a percentage of the static MOR, and Nf is the
number of cycles to failure. The coefficient of correlation for the above equation is 0.976.
It can be inferred that the fatigue life of HESFRC containing 2% by volume of hooked steel
fibers is on the order of 68% of their static flexural strength for 5 million cycles, 67% for
10 million cycles, and 65% for 50 million cycles. For all practical purposes, a stress rangeof 65% can be taken as the endurance lirrdt.
3. Mixes A2%S3 and A2%S3S5, reinforcext with 2% hooked-end steel fibers, with aspect
ratios of 60 and a mix of 60 and 100, respectively, showed similar behavior under fatigue
loading.
4. HESFRC mixes containing 2% by volume of hooked steel fibers can sustain substantially
higher fatigue stresses than plain concrete without fibers.
9.5 Recommendations
For HESFRC mixes with 2% hooked steel fibers by volume, a safe endurance limit for cyclic
fatigue loading in bending can be taken at about 65% of the static ultimate strength (or
equivalently the MOR) obtained from a control specimen with fibers. This result should be
valid even if the beam is cracked at maximum load.
156
9.6 References
1. Ramakrishnan, V., G. Oberling, and P. TatnaU "Flexural Fatigue Strength of Steel FiberReinforced Concrete. Fiber Reinforced Concrete: Properties and Applications. SP 105-13. American Concrete Institute, Detroit (1987): 225 - 245.
2. Ramakrishnan, V., G. Y. Wu, and G. Hosalli "Flexural Fatigue Strength, EnduranceLimit, and Impact Strength of Fiber Reinforced Concretes" paper presented at the 68thAnnual Meeting of the Transportation Research Board,Washington, D.C., January 1989.
3. Ramakrishnan, V., and B. J. Lokvik "Flexural Fatigue Strength of Fiber ReinforcedConcretes" High Performance Fiber Reinforced Cement Composites, RILEMProceedings 15, H.W. Reinhardt and A.E. Naaman, Chapman and Hall, London, 1992.
157
10
Summary and Recommendations
The Executive Summary at the beginning of this volume provides some general
recommendations relevant to all mechanical properties of HESFRC mixes tested in this
investigation. Specific conclusions related to the compression, bending, tension, and
fatigue properties of HESFRC mixes can be found at the end of chapters 6, 7, 8 and 9,
respectively. Recommendations related to the compression, bending, tensile, and fatigue
properties are given in this chapter. The conclusions and recommendations of this study
relate to hooked steel fibers and monofilament polypropylene fibers and do not necessarily
apply to other types of fibers.
10.1 Compression Tests
An extensive experimental investigation was carried out on the compressive properties of
HESFRC. Tests on the mechanical properties included compressive strength and elastic
modulus with time. In all, 16 different mixes were investigated. The database gathered
comprised (1) the stress versus strain response in compression of each time series and its
representative average; (2) a comparison of various time series taken from the same mix;
(3) a comparative evaluation of different mixes at 1 and 28 days; and (4) a comparison of
the compressive strength and elastic modulus of various mixes with time.
The following recommendations were arrived at
1. The use of 1 to 2% by volume of 30/50 hooked steel fibers gave optimum composite
properties in the fresh and hardened state. It caused a significant increase in the
compressive strength, elastic modulus, and ductility when compared with all other
HESFRC mixes.
159
2. Next in performance was the use of 1% by volume of either 30/50 + 50/50 steel fibers
or 50/50 steel fibers. Both mixes performed very similarly in terms of compressive
strength, elastic modulus, and stress-strain response. The 1-day compressive strength
of these mixes exceeded the required rrtmimurn of 5 ksi.
3. Mixes containing 1 to 2% by volume of polypropylene fibers showed deterioration in
the compressive stress-strain response when compared with the control mix. Therefore,
the use of polypropylene fibers alone to improve strength and elastic modulus is not
desirable. However, the use of 1% by volume of polypropylene fibers in conjunction
with 1% by volume of 30/50 hooked steel fibers in the same HESFRC mix led to a
slight improvement in the compressive stress-strain properties.
4. Although latex improved the workability of HESFRC mixes, it is not desirable to use
latex with HESFRC mixes for the purpose of improving early age properties.
However, latex did improve the long-term compressive stress-strain response ofHESFRC mixes.
5. Silica fume had no significant effect on the compressive strength at I day. However, it
significantly increased the compressive strength of HESFRC mixes at later ages.
10.2 Bending Tests
The properties of HESFRC subjected to static flexural loading were studied. The
experimental program included flexural testing at 1, 7, and 28 days. In all, 17 different
mixes were investigated. The data gathered included (1) the load vs. deflection and load vs.
strain capacity response in flexure of each time series and its representative average; (2) a
comparison of various time series taken from the same mix; (3) a comparative evaluation of
different mixes at 1 and 28 days; and (4) a comparison of the toughness indices versus time
for various mixes using the ASTM C 1018 approach (which uses the first cracking load)
and the control test approach.
The following recommendations regarding the response of all HESFRC composites inflexure were arrived at:
160
10.2.1 Recommendations Based on Strength Criteria
1. The optimum mix that gave the highest flexural strength at 1 day was the mix
containing 2% by volume of 30/50 hooked steel fibers (A2%S3). Therefore, this mix is
recommended for applications requiring high early tensile strength.
2. Next in performance was the hybrid mix containing 2% by volume of 30/50 + 50/50
hooked steel fibers (A2%S3S5).
3. The bending properties of the mix containing 1% by volume of 50/50 hooked steel
fibers were also considered very good.
4. The use of polypropylene fibers alone in HESFRC mixes is not considered very
effective, since mixes containing polypropylene fibers showed lower strengths at early
ages and poorer post cracking load-deflection response than mixes containing equal
volumes of hooked steel fibers. However, hybrid mixes with steel and polypropylene
fibers fared much better.
5. The use of latex in HESFRC composites is not desirable in applications for which high
early strength is sought. However, the tensile properties of HESFRC composites
containing latex significantly improved with time. Therefore, ff the objective is to obtain
high-tensile, long-term strength, latex is recommended for use with mixes containing
1% by volume of 50/50 or 30/50 + 50/50 steel fibers. It should be observed that latex
is generally used to improve other properties, such as bonding between new and old
concrete in repair applications, and durability. These very important properties were
not tested in this investigation. However, it is expected that they would be improved in
HESFRC mixes just as they would for plain concrete mixes.
6. The addition of silica fume does not significantly affect the 1-day flexural properties of
HESFRC composites. However, tensile properties are improved at later ages.
10.2.2 Recommendations Based on Energy Absorption (Toughness)Criteria
1. The following mixes can be considered to have equal optimal energy absorption
properties: mix containing 2% of 30/50 fibers (A2%S3), hybrid mix containing 2% of
161
30/50 + 50/50 fibers (A2%S3S5), and the latex HES mix containing 1% of 50/50
fibers (B 1%S5).
2. Next in performance come the hybrid latex and silica fume HESFRC mixes containing
1% of 30/50 + 50/50 fibers (B1%S3S5 and C1%$3S5, respectively).
3. All other HESFRC mixes containing either hooked steel fibers or a combination of
polypropylene and hooked steel fibers showed lower, but acceptable, energy
absorption properties.
4. The toughness indices of HESFRC mixes containing polypropylene fibers were
substantially lower than those achieved 'with equal volumes of hooked steel fibers;
however with 1 and 2% fibers by volurne, toughness indices I5 and I10 were within
the limit recommended (targeted) in this study for HESFRC (i.e., 15 > 5 and I10 > 10).
If the objective is to obtain high toughness, impact or energy absorption properties, the
use of steel fibers in HESFRC mixes is preferred over polypropylene fibers.
10.3 Splitting Tensile Tests
This section summarizes the main results of this part of the experimental investigation,
which included splitting tensile and compressive tests at 1 day. In all, 17 different mixes
were investigated. The following recommendations regarding the splitting tensile and
compressive strengths are proposed:
1. The optimal mix that gave the highest spatting tensile and compressive strengths at 1
day was the mix containing 2% by volume of 30/50 hooked steel fibers (A2%S3).
Therefore, this mix is recommendedfor applications requiring high early tensile
strength.
2. Next in performance was the hybrid mix containing 2% by volume of 30/50 + 50/50
hooked steel fibers (A2%S3S5).
3. The tensile properties of the mix containing 1% by volume of 50/50 hooked steel fibers
were also considered very good.
4. The use of polypropylene fibers alone in HESFRC mixes produced lower tensile
strengths than mixes with equal volume of hooked steel fibers, but higher strengths
162
thanthecontrolmix withoutfibers.Moreover,hybridmixeswithsteeland
polypropylenefibersfaredmuch better.
5. The useoflatexinHESFRC compositesisnotdesirableinapplicationsforwhichhigh
carlystrengthissoughtHowever,thetensilepropertiesofHESFRC composites
containing latex significantly improved with time. Therefore, ff the objective is to obtain
high-tensile, long-term strength, latex is recommended for use with mixes containing
1% by volume of 50/50 or 30/50 + 50/50 steel fibers. It should be observed that latex
is generally used to improve other properties, such as bonding between new and old
concrete in repair applications, and durability. These very important properties were
not tested in this investigation. However, it is expected that they would be improved in
HESFRC mixes just as they would for plain concrete mixes.
6. The addition of silica fume does not significantly affect the 1-day tensile properties of
HESFRC composites. However, tensile properties are improved at later ages.
10.4 Fatigue Tests
Specimens reinforced with hooked steel fibers atvolume fractions of 2% showed average
fatigue lives on the order of 10 cycles for loads ranging between 10 and 90% of their static
strength, 8,000 cycles for loads ranging between 10 and 80%, and more than 2.7 x 106
cycles for loads ranging between 10 and 70%. These values hold if the specimens are
cracked. Substantially larger values can be achieved with uncracked specimens.
The endurance limit of HESFRC containing 2% by volume of hooked steel fibers is on the
orderof 65% of their static flexural strength.
10.5 Recommendations for Future Research
Theresultsachievedinthisinvestigationcanbeconsideredageneralguideonthe
feasibilityofproducingHESFRC with(1)atargetcompressivestrengthof5ksi(35MPa)
at24hours;(2)apostcrackingstrengthinbending(modulusorrupture)largerthanthe
crackingstrength;and(3)toughnessindicesI5and110respectively,largerthan5 and10.
Whcraslocalconditionsandmaterialsusedfortheconcretematrixwillleadtosmall
anticipatedvariations,theuseoffibersdifferentfromthoseselectedinthisstudymay lead
163
to substantial differences in results. It is thus recommended that an evaluation of the use of
different types of fibers in HESFRC mixes _ undertaken and some correlation between
results using different fibers be established. Similarly, there is need to establish a cost-
effectiveness evaluation of the benefits of using fibers in transportation structures.
VES concrete was covered in volume 3. However, no attempt was made to explore VES
concrete with fibers. If the applications of VES concrete are for rapid repair, such as for
bridge decks and pot holes, then the addition of fibers can only improve the properties
needed for such applications. It is thus recommended that the properties of VES fiber
reinforced concrete be studied in a manner similar to that undertaken for HESFRC.
The selected fatigue tests undertakenin this study were for mixes containing 2% by volume
of hooked steel fibers. A fatigue limit of 65% of ultimate was observed, even in pre-
cracked specimens. There is a need to check whether a smaller volume fraction of hooked
steel fibers (say, 1 or 1.5%) in HESFRC mixes, or the use of other types of fibers willlead to a similar result.
Although, as demonstrated in this study, many mechanical properties can be substantially
improved by adding fibers to concrete, the most dramatic improvement is observed in the
toughness or energy absorption capacity of the composite. This property is particularly
useful in pavements, overlays, and runways applications for which impact and fatigue are
critical. A life-cycle cost evaluation of the benefits of adding fibers to such structures isrecommended.
164
Bibliography
General Background History Books
ACI Committee 544. State of the Art Report on Fiber Reinforced Concrete(AC1544. IR-82). Concrete International: Design and Construction, May 1982,pp. 9 - 30. Also published separately by American Concrete Institute, 1982,and Manual of Concrete Practice part 5.
ACI Committee 544. Design Considerations for Steel Fiber ReinforcedConcrete. ACI Structural Journal, voi.85, no. 5 (September - October 1988):563 - 580.
ACI Committee 544. Guide for Specifying, Proportioning, Mixing, Placing,and Finishing Steel Fiber Reinforced Concrete. ACI Materials Journal, 90, no.1 (January- February 1993): 94- 101.
Alkhairi, F.M., and A.E. Naaman. An Annotated Bibliography on HighStrength Fiber Reinforced Concrete. Department of Civil Engineering,University of Michigan, Report No. UMCE 91-08, December 1991.
Balaguru, P.N., and S.P.Shah. Fiber Reinforced Cement Composites. NewYork, McGraw Hill: 1992.
Hannant, D.J. Fiber Cements and Fiber Concretes. Chichester, England, Wiley& Sons: 1984.
Naaman, A. E. "Fiber Reinforcement for Concrete." Concrete International,vol. 7, no. 3 (March 1985): 21 - 25.
Naaman, A. E., and M. H. Harajli. Mechanical Properties of HighPerformance Fiber Concretes: A State-Of-The-Art Report (SHRP-C/WP-90-004). SHRP National Research Council; Washington D.C., 1990.
Naaman, A.E., and F.M. Alkhairi. Fresh and Hardened Propern'es of HighEarly Strength Fiber Reinforced Concrete (HESFRC), Compressive Strengthand Modulus of Elasticity with Time. Depaaianent of Civil Engineering,University of Michigan, UMCE Report No. 91-08, August 1991, 211 pages.
165
Naaman, A.E., and F.M. Alkhairi. Flexural and Splitting Tensile Properties ofHigh Early Strength Fiber Reinforced Concrete. Depaztment of CivilEngineering, University of Michigan, Report No. UMCE 92-08, April 1992.
Reinhardt, H.W., and A.E. Naaman. High Performance Fiber ReinforcedCement Composites. (RILEM Proceedings 15), Chapman and Hall, London,1992.
Zia, P., M.L. L_mming,and S.H. Ahmad. High Performance Concretes: A State-of-the-Art Report.. Report no. SHRP-C-317. SHRP, National Research Council,Washington, D.C. 1991.
Compression
ACI Committ_ 318. Building Code Requirements for Reinforced Concrete(AC1318-83). American Concrete Institute, Detroit. 1983.
ACI Committee 544. "Measurement of Properties of Fiber ReinforcedConcrete." ACI Material Journal, vol.85, no. 6 (Nov-Dec 1988): 583 - 593.
Balaguru, P., and V. Ramakrishnan. Mechanical Properties of SuperplasticizedFiber Reinforced Concrete Developed for Bridge Decks and HighwayPavements. In Proceedings, Concrete in Transportation, ACI SP 93, Detroit(Sept 1986).
Balaguru, P., and V. Ramakrishnan. "Properties of Lightweight FiberReinforced Concrete. In Fiber Reinforced Concrete: Properties andApplications, SP 105-17, American Concrete Institute, Detroit (1987): 305 -322.
Bharyava, J.K. "Polymer-Modified Concrete for Overlays: Strength andDevelopment Characteristics." In Application of Polymer to Concrete, SP-69,American Concrete Institute, Detroit (1981): 205 - 218.
Fanella, D. A., and A. E. Naaman. "Stress-Strain Properties of FiberReinforced Concrete In Compression." ACI Journal, voi.82, no. 4 (July-August 1985): 475 - 483.
Homrich, J. R., and A. E. Naaman. "Stress-Strain Properties of SIFCON inCompression." Fiber Reinforced Concrete: Propern'es and Applications, SP105-16, American Concrete Institute, Detroit (1987): 283 - 304.
Mason, J.A. "Overview of Current Research on Polymer Concrete: Materialand Future Needs." In Application of Polymer to Concrete, SP-69, AmericanConcrete Institute, Detroit (1981): 1 - 20.
Mondragon, 1L Development of Material Properties for Slurry Infiltrated FiberConcrete (SIFCON)- Compressive Strength." New Mexico EngineeringResource Institute, Part 1 of 2 NMERI WA 8-18, Albuquerque (Dec 1985).
166
Mondragon, R. "SIFCON in Compression." Fiber Reinforced Concrete:Properties and Applications, SP 105-1, American Concrete Institute, Detroit(1987): 260 - 281.
Najm, H. "Mechanical Properties of High Performance Cement BasedComposites." Ph.D. thesis, Department of Civil Engineering, University ofMichigan. 1992.
Otter, D., and A. E. Naaman. "Steel Fiber Reinforced Concrete under Staticand Cyclic Compressive Loading." InProceedings of Third InternationalSymposium on Developments in Fiber Reinforced Cement and Concrete. R.N. Swamy, R. L. Wagstaffe, and D. R. Oakley. Sheffield, England (July1986).
Otter, D., and A.E. Naaman. "Model For Response of Concrete To RandomCompressive Loads." Journal of Structural Engineering, ASCE, vol. 115, no.11 (November 1989): 2794- 2809.
Soroushian, P., F. Aouadi, and M. Naji. "Latex-Modified Carbon FiberReinforced Mortar." ACI Material Journal, vol. 88, no. 1 (January/February1991): 11-18.
Bending
ACI Committee 544. "Design Considerations for Steel Fiber ReinforcedConcrete," ACI Structural Journal, vol. 85, no. 5 (Sep-Oct 1988): 563 - 580.
Akihama, S., M. Kobayashi, T. Suenaga, H. Nakagawa, and K. Suzuki."Effect of CFRC Specimen Geometry on Flexural Behavior." Paper presentedat the 3rd RILEM International Symposium on Fiber Reinforced CementComposites, Sheffield, England, 1986.
ASTM. Standard Test Method for Flexural Toughness and First-CrackStrength of Fiber-Reinforced Concrete (Using Beam with Third-PointLoading). ASTM C1018-89, vol. 04.02.
Balaguru, P., and V. Ramakrishnan. "Properties of Lightweight FiberReinforced Concrete." In Fiber Reinforced Concrete: Prope_'es andApplications, SP 105-17, American Concrete Institute, Detroit (1987): 305 -322.
Hibbert, A. P., and D.J. Hannant. "Toughness of Fibre Cement Composites."Composites, vol. 13 (Apr 1982): 105- 111.
Johnston, C.D. "Definition and Measurement of Flexural ToughnessParameters For Fiber Reinforced Concrete." Cement, Concrete, andAggregates, vol. 4, no. 2 (1982): 53 - 60.
Johnston, C. D. "precision of Flexural Strength and Toughness Parameters forFiber Reinforced Concrete." Cement, Concrete, and Aggregates, vol. 4, no. 2(1982): 61 - 67.
167
Johnston, C. D. "Steel Fiber Reinforced and Plain Concrete: FactorsInfluencing Flexural Strength Measurement." Journal of the American ConcreteInstitute, vol. 79, no. 2 (1982): 131 - 138.
Johnston, C. D., and R. J. Gray. "Flexural Toughness and First-CrackStrength of Fiber Reinforced Concrete." Paper presented at the 3rd RILEMInternational Symposium on Fiber Reinforced Cement Composites, Sheffield,England. July 1986.
Lira, T. Y., P. Paramasivam, and S L. Lee. "Bending Behavior of Steel-FiberConcrete Beams." ACI Structural Journal, vol. 84, no. 6 (Nov-Dec 1987): 524- 536.
Mangat, P. S., and K. Gurusamy. "Flexural Strength of Steel Fibre ReinforcedCement Composites." Journal of Material Science, vol. 22 (1987): 3103 -3110.
Ohama, Y., S. Kan, and M. Miyara "Flexural Behavior of Steel FiberReinforced Polymer-Modified Concrete." Transactions of the JapaneseConcrete Institute, vol. 4 (Dec 1982): 147 - 152.
Ramakrishnan, V., G. Y. Wu, and G. Hosalli. "Flexurai Behavior andToughness of Fiber Reinforced Concretes." Paper presented at the 68th AnnualMeeting of the Transportation Research Board. Washington, D.C. (January1989).
Ramakrishnan, V., W. V. Coyle, V. Kulandaisamy, and E. K. Schrader."Performance Characteristics of Fiber Reinforced Concrete With Low FiberContent." Journal of the American Concrete Institute, vol. 78, no. 5 (Sept-Oct1981): 388 - 394.
Sakai, M., and N. Nakamura. "Studies on Characteristics and FlexuralBehavior of Steel Fiber Reinforced Concrete." Japanese Concrete Institute, vol.2 (1984): 11 - 18.
Swamy, R. N., and S. A. A1-Ta'an. "Deformation and Ultimate Strength inFlexure of Reinforced Concrete Beams With Steel Fiber Concrete." Journal ofthe American Concrete Institute, vol. 78, no. 5 (Sept-Oct 1981): 395 - 405.
Tension
ACI Committee 544. Measurement of Properties of Fiber Reinforced Concrete,ACIMaterialJournal, vol. 85, no. 6 (Nov-Dec 1988): 583 - 593.
Johnston, C. D., and R. J. Gray. "Uniaxial Tensile Testing of Steel FibreReinforced Cementitious Composites." In Proceedings, RILEM Symposium onTesting and Test Methods of Fibre Cement Composites. Construction Press.Lancaster, England (1978): 451 - 461.
Laws, V. "Derivation of The Tensile Stress-Strain Curve from Bending Data."Journal ofMaterialScience, vol. 16 (1981): 1299- 1304.
168
Laws, V., and P. L. Walton. "The Tensile-Bending Relationships for FibreReinforced Brittle Matrices." In Proceedings, R1LEM Symposium, Testingand Test Methods of Fiber Cement Composites. R. N. Swamy, ed., Lancaster,England (1978): 429 - 438.
Lira, T. Y., P. Paramasivam,, and S. L. Lee. "Analytical Model For TensileBehavior of Steel-Fiber Concrete." ACI Material Journal, vol. 84, no. 4 (July-Aug 1987): 286 - 298.
Lira, T. Y., P. Paramasivam, M. A. Mansur, and S. L. Lee. "TensileBehavic,ur of Steel Fibre Reinforced Cement Composites." In RILEMSymposium Proceedings, FRC 86 Developments in Fiber Reinforced Cementand Concrete. Edited by R. N. Swamy, R. L. Wagstaffe, and D. R. Oaldey.vol. 1, July 1986.
Lub, K. B., and T. Padmoes. "Mechanical Behavior of Steel Fiber-CementMortar in Tension and Flexure, Interpreted By Means of Statistics." ACIMaterial Journal, vol. 86, no. I (Jan-Feb 1989): 16 - 27.
Naaman, A. E. "High Performance Fiber Reinforced Composites." InProceedings, Concrete Structures for the Future, IABSE Symposium, Paris,Versailles (1987): 371 - 376.
Nanni, A. "Splitting-Tension Test for Fiber Reinforced Concrete." ACIMaterial Journal, vol. 85, no. 4 (July-Aug 1988): 229 - 233.
Potrzebowski, J. "The Splitting Test Applied to Steel Fibre ReinforcedConcrete." International Journal of Cement Composites and LightweightConcrete, vol. 5, no. 1 (Feb 1983): 49 - 53.
Shah, S. P., P. Stroeven, D. Dalhuisen, and V. Stekelenburg. "CompleteStress-Strain Curves for Steel Fiber Reinforced Concrete in Uniaxial Tensionand Compression." In Testing and Test Methods of Fiber Cement Composites,RILEM Symposium, Construction Press, Lancaster (1978): 399 - 408.
Flexural Fatigue
Batson, G., C. Ball, L. Bailey, E. Landers, and J. Hooks. "Flexural FatigueStrength of Steel Fiber Reinforced Concrete Beams." Journal of the AmericanConcrete Institute, vol. 69, no. 11 (Nov 1972): 673 - 677.
Ramakrishnan, V., G. Oberling, and P. Tatnall. "Flexural Fatigue Strength ofSteel Fiber Reinforced Concrete." Fiber Reinforced Concrete: Properties andApplications, SP 105-13, American Concrete Institute, Detroit (1987): 225 -245.
Ramakrishnan, V., G. Y. Wu, and G. Hosalli. "Flexural Fatigue Strength,Endurance Limit, and Impact Strength of Fiber Reinforced Concretes." Paperpresented at the 68th Annual Meeting of the TransportationResearch Board.Washington, D.C., January 1989.
169
Ramakrishnan, V., S. GoUapudi, and R. Zellers. "PerformanceCharacteristics and Fatigue Strength of Polypropylene Fiber ReinforcedConcrete." In Fiber Reinforced Concrete: Properties and Applications, SP 105-9, American Concrete Institute, Detroit (1987): 159 - 177.
Ramakrishnan, V., T. Brandshaug, W. V. Coyle, and E. K. Schrader. "AComparative Evaluation of Concrete Reinforced with Straight Steel Fibers andFiber with Deformed Ends Glued "l'ogether in Bundles." Journal of theAmerican Concrete Institute, vol. 77, no. 3 (May 1980): 135 - 143.
Ramakrishnan, V. Coyle W. V., ¥. Kulandaisamy, and E.K. Schrader."Performance Characteristics of Fiber Reinforced Concrete with Low FiberContent." Journal of the American Concrete Institute, vol. 78, no. 5 (Sept-Oct1981): 388 - 394.
Pavement Applications
Hanna, A.N. "Steel Fibers Reinforced Concrete Properties in ResurfacingApplication." Research and Development Bulletin, RD 49.01P. PortlandCement Association, Skokie, Illinois (1977).
Shrader, E.K. Design Methods for Pavements with Special Concretes.American Concrete Institute Special Publication SP-81, Detroit (1984): 197 -212.
Johnston, C.D. "Steel Fiber Reinforced Pavements Trials." Concrete International,vol. 6, no. 12 (Dec. 1984): 39 - 43.
Packard, R.G., and G.K. Ray. Performance of Fiber Reinforced ConcretePavements. American Concrete Institute Special Publication SP-81, Detroit(1984): 325 - 349.
Shrader, E.K. "Fiber Reinforced Concrete Pavements and Slabs." Paperpresented at US Sweden Joint Seminar (NSF-STU), Stockholm (June 1985): 109 -131.
Wu, G., and M. Jones. "Navy Experience with Steel Fiber Reinforced ConcreteAirfield Pavement." In Fiber Reinforced Concrete Properties and Applications, SP-105, American Concrete Institute, Detroit (1987): 403 - 418.
170
Appendix A
Compression Tests
Table A.1 - A.16: Tables of Values of Pc and Ec for each Specimen and AverageValues and Standard Devision of each Series.
Fig. A.I - A.79: Stress versus Strain Curves for each Series and its
Representative Average Curve.
Fig. A.80 - A.94: Stress versus Strain Response with Time and Effect of
Cylindrical Size.
Fig. A.95 - A.104: Stress versus Strain response for Different Series.
Fig. A.105 - A. 111: Compressive Strength f'c.
Fig. A.112 - A.120: Elastic Modulus.
171
Table A.1. Ec and f'c Values for the Control Mix
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Strength (ksi)
Control 1D48fc 1 3976.4 4.74
Control 1D48fc2 4124.87 5.47
Control 1D48fc3 4287.56 5.03
Control-AV 1D48fcA 4129.61 5.08
Control-SD 1D48fcS 155.63 0.37
Control 1D612fcl --- 4.14
Control 1D612fc2 --- 4.83
Control-AV 1D612fcA --- 4.485
Control-S D 1D612fcS --- 0.49
Control 3D48fc 1 4434.05 6.66
Control 3D48fc2 4201.178 7.27
Control 3D48fc3 3829.906 5.73
Control-AV 3D48fcA 4155.04 6.55
Control-S D 3D48fcS 304.70 0.78
Control 7D48fcl 3826.6 7.14
Control 7D48fc2 4400.08 7.3
Control 7D48fc3 3889.85 6.33
Control-AV 7D48fcA 4038.84 6.92
Control-SD 7D48fcS 314.43 0.52
Control 28D48fc 1 3852.337 7.5
Control 28D48fc2 3724.33 6.8
Control 28D48fc3 3804.466 6.7
Control-AV 28D48fcA 3793.71 7.00
Control-SD 28D48fcS 64.68 0.44
172
Table A.2. Ec and f'c Values for the 30/50 Mix (Vf = 1% by)
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Strength (ksi)
A1%S3 1D48fcl 4616.34 5.75
A1%S3 1D48fc2 3938.67 5.96
A1%S3 1D48fc3 4671.34 6.2
A1%S3-AV 1D48fcA 4408.78 5.97
AI%S3-SD 1D48fcS 408.06 0.23
A1%S3 1D612fcl .... 5.1
A1%S3 1D612fc2 .... 6.05
A 1%S3-AV 1D612fcA .... 5.575
AI%S3-SD 1D612fcS .... 0.67
A1%S3 3D48fc I 4281.02 6.74
A 1%S3 3D48fc2 4051.88 6.53
A 1%S3 3D48fc3 3592.57 6.722
A 1%S3-AV 3D48fcA 3975.16 6.66
A 1%S3-SD 3D48fcS 350.58 0.12
A1%$3 7D48 fc 1 4695 7.1
A1%S3 7D48fc2 4438.13 7.5
A1%S3 7D48fc3 4800 8.03
A1%S3-AV 7D48fcA 4644.38 7.54
A1%S3-SD 7D48fcS 186.17 0.47
A 1%S3 28D48fc 1 5683 8.24
A1%S3 28D48fc2 4350 6.8
A 1%S3 28D48fc3 4300 7.98
A 1%S3-AV 28D48 fcA 4777.67 7.67
AI%S3-SD 28D48fcS 784.44 0.77
173
Table A.3. Ec and f'c Values for the 30/50 Mix (Vf = 2%)
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Strength (ksi)
A2%S3 1D48fcl 6846 6.2
A2%S3 1D48fc2 4563 5.9
A2%S3 1D48fc3 7798.58 6.1
A2%S3-AV 1D48fcA 6402.53 6.07
A2%S3-SD 1D48fcS 1662.75 0.15
A2%S3 1D612fcl --- 4.5
A2%S3 1D612fc2 --- 4.8
A2%S3-AV 1D612fcA --- 4.65
A2%S3-SD 1D612fcS --- 0.21
A2%S3 3D48 fc 1 4041.1 6.25
A2%S3 3D48fc2 4022.3 6.7
A2%S3 3D48fc3 4216.36 7.18
A2%S3-AV 3D48fcA 4093.25 6.71
A2%S3-SD 3D48fcS 107.03 0.47
A2%S3 7D48fcl 4704 7.4
A2%S3 7D48fc2 4353.11 7.5
A2%S3 7D48fc3 4036.87 7.76
A2% S3-AV 7D48fcA 4364.66 7.55
A2%S3-SD 7D48fcS 333.71 0.19
A2 %S3 28D48fc 1 3625.83 7.3
A2%S3 28D48fc2 3875.35 7.4
A2%S3 28D48fc3 4030.2 8.1
A2%S3-AV 28D48fcA 3843.79 7.60
A2%S3-SD 28D48fcS 204.02 0.44
174
Table A.4. Ec and f'e Values for the 50/50 Mix (Vf= 1%)
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Strength (ksi)
A1%S5 1D48fcl 3907 4.75
A 1%S5 1D48fc2 3403.5 5.1
A1%S5 1D48fc3 3180.4 5.3
A 1%S5-AV 1D48fcA 3496.97 5.05
A 1%S5-SD 1D48fcS 372.21 0.28
A1%S5 1D612fcl --- 5.2
A1%S5 1D612fc2 --- 6
AI%S5-AV 1D612fcA --- 5.6
AI%S5-SD 1D612fcS --- 0.57
A1%S5 3D48fcl 3436.4 5.6
A1%S5 3D48fc2 3634.45 5.7
A 1%S5 3D48 fc3 3497.3 5.85
A 1%S5-AV 3D48fcA 3522.72 5.72
AI%S5-SD 3D48fcS 101.44 0.13
A1%S5 7D48fcl 3601.8 5.1
A1%S5 7D48fc2 3740.91 6.5
A 1%S5 7D48fc3 3694.17 6.35
A 1%S5-AV 7D48fcA 3678.96 5.98
A1%S5-SD 7D48 fcS 70.79 0.77
A1%S5 28D48fcl 2689.37 5.5
A1%S5 28D48fc2 2413.3 6.6
A1%S5 28D48fc3 2992 6.8
AI%S5-AV 28D48fcA 2698.22 6.30
A1%S5-SD 28D48fcS 289.45 0.70
175
Table A.5. Ec and f'c Values for the 0.75 in. Long Polypropylene Mix (Vf = 1%)
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Stren[th (ksi)A1%P0.75 1D48fc 1 2889 4.22
A1%P0.75 1D48fc2 2700.66 4.08
Al%P0.75 1D48fc3 3188.54 ---
A1%P0.75-AV 1D48fcA 2926.07 4.15
Al%P0.75-SD 1D48fcS 246.04 0.10
A 1%P0.75 1D612fc 1 --- 4.4
Al%P0.75 1D612fc2 --- 4.65
Al%P0.75-AV 1D612fcA --- 4.525
A 1%P0.75-SD 1D612fcS --- 0.18
A1%P0.75 3D48fc 1 3055.11 4.57
A1%P0.75 3D48fc2 3139.75 5.11
A1%P0.75 3D48fc3 3170.15 5.17
Al%P0.75-AV 3D48fcA 3121.67 4.95
A1%P0.75-SD 3D48fcS 59.61 0.33
A1%P0.75 7D48fc 1 3284.55 5.9
A1%P0.75 7D48fc2 3197.18 6
A1%P0.75 7D48fc3 3262.208 5.6
Al%P0.75-AV 7D48fcA 3247.98 5.83
Al%P0.75-SD 7D48fcS 45.39 0.21
A 1%P0.75 28D48 fc 1 2901.07 5.67
A 1%P0.75 28D48fc2 3006.11 5.44
A1%P0.75 28D48fc3 3004.9 5.56
Al%P0.75-AV 28D48fcA 2970.69 5.56
Al%P0.75-SD 28D48fcS 60.30 0.12
176
Table A.6. Ec and f'c Values for the 0.75 in. Long Polypropylene Mix (Vf = 2%)
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Strength (ksi)
A2%P0.75 1D48fc 1 2881.6 2.8
A2%P0.75 1D48fc2 2784.7 3i
A2%P0.75 1D48fc3 2688.9 3.4
A2%P0.75-AV 1D48fcA 2785.07 3.07
A2%P0.75-SD 1D48fcS 96.35 0.31
A2%P0.75 1D612fcl --- 2.2
A2%P0.75 1D612fc2 --- 3
A2%P0.75-AV 1D612fcA --- 2.6
A2%P0.75-SD 1D612fcS --- 0.57
A2% P0.75 3D48 fc 1 2947.28 4.41
A2%P0.75 3D48fc2 3044.25 4.1
A2%P0.75 3D48fc3 2997.02 4.57
A2%P0.75-AV 3D48fcA 2996.18 4.36
A2%P0.75-SD 3D48fcS 48.49 0.24
A2%P0.75 7D48fcl 2667 4.41
A2%P0.75 7D48fc2 2513.4 4.29
A2%P0.75 7D48fc3 2848.95 5.05
A2%P0.75-AV 7D48fcA 2676.45 4.58
A2%P0.75-SD 7D48fcS 167.97 0.41
A2%P0.75 28D48fc 1 2560.88 4.25
A2%P0.75 28D48fc2 2635.96 4.65
A2%P0.75 28D48fc3 2764.75 5.4
A2%P0.75-AV 28D48fcA 2653.86 4.77
A2%P0.75-SD 28D48fcS 103.11 0.58
177
Table A.7 - Ec and f'c Values for the 30/50 + 50/50 Hybrid Mix (Vf = 1%)
Mix ID Specimen ]D Elastic Modulus Compressive
(ksi) Strength (ksi)A 1%S3S5 1D48fc 1 3938.115 5.83
A 1%S3S5 1D48fc2 3811.25 5.01
A 1%$3S5 1D48fc3 3741.72 5.69
A 1%S3S5-AV 1D48fcA 3830.36 5.51
A l%S3S5-SD 1D48fcS 99.58 0.44
A1%S3S5 1D612fcl --- 4.03
A1%S3S5 1D612fc2 --- 4.14
AI%S3S5-AV 1D612fcA --- 4.085
A 1%S3S5-SD 1D612fcS --- 0.08
A 1%S3S5 3D48fc 1 1770.72 6.38
A 1%S3S5 3D48fc2 1994.05 6.4
A 1%S3S5 3D48fc3 2001.3 6
A I%S3S5-AV 3D48fcA 1922.02 6.26
A 1%S3S5-SD 3D48fcS 131.08 0.23
A1%S3S5 7D48fc 1 3540.97 6.37
A1%S3S5 7D48fc2 3628.95 7.52
A 1%S3S5 7D48fc3 3529.15 6.9
A 1%S3S5-AV 7D48fcA 3566.36 6.93
A 1%S3S5-SD 7D48fcS 54.53 0.58
A 1%S3S5 28D48fc 1 3923.94 7.64
A1%S3S5 28D48fc2 3889.53 7.89
A1%S3S5 28D48fc3 4016.71 8.12
AI%S3S5-AV 28D48fcA 3943.39 7.88
AI%S3S5-SD 28D48fcS 65.78 0.24
178
Table A.10. Ec and f'c Values for the 30/50 + Polypropylene Hybrid Mix (Vf = 2%)
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Stren[th (ksi)
A2%S3P0.5 1D48fcl 3422.08 4.35
A2%S3P0.5 1D48fc2 3512.45 4.75
A2%S3P0.5 1D48fc3 3381.56 5.01
A2%S3P0.5-AV 1D48fcA 3438.70 4.70
A2%S3P0.5-SD 1D48fcS 67.01 0.33
A2%S3P0.5 1D612fcl --- 3.64
A2%S3P0.5 1D612fc2 --- 3.71
A2%S3P0.5-AV 1D612fcA --- 3.675
A2%S3P0.5-SD 1D612fcS --- 0.05
A2%S3P0.5 3D48fc 1 3531.66 5.06 ,I
A2%S3P0.5 3D48fc2 3475.15 5.32
A2%S3P0.5 3D48fc3 3583.05 5.13
A2%S3P0.5-AV 3D48fcA 3529.95 5.17
A2%S3P0.5-SD 3D48fcS 53.97 0.13
A2%S3P0.5 7D48fc 1 2989.48 4.06
A2%S3P0.5 7D48fc2 2923.34 6.43
A2% S3P0.5 7D48fc3 3063.57 6.02
A2%S3P0.5-AV 7D48fcA 2992.13 5.50
A2%S3P0.5-SD 7D48fcS 70.15 1.27II
A2%S3P0.5 28D48fcl 1574.86 5.98
A2%S3P0.5 28D48fc2 1428.16 6.22
A2%S3P0.5 28D48fc3 1542.05 5.91
A2%S3P0.5-AV 28D48fcA 1515.02 6.04
A2%S3P0.5-SD 28D48fcS 76.99 0.16
179
Table A.11. Ee and f'c Values for the Latex Control Mix (Vf = 0%)
Mix ID Specimen I]) Elastic Modulus Compressive
(ksi) Strength (ksi)
B0%Con 1D48fcl 2191.8 4.45
B0%Con 1D48fc2 2352.8 4.22
B0%Con 1D48fc3 ......
B0%Con-AV 1D48fcA 2272.3 4.34
B0%Con-SD 1D48fcS 113.84 0.16
B0%Con 1D612fcl ......
B0%Con 1D612fc2 ......
B0%Con-AV 1D612fcA ......
B0%Con-SD 1D612fcS ......
B0%Con 3D48fc 1 4713 6.24
B0%Con 3D48fc2 2800 6.25
B0%Con 3D48fc3 ......
B0%Con-AV 3D48fcA 3756 6.25
B0%Con-SD 3D48fcS 1352 0.01
B0%Con 7D48fc 1 3065 5.83
B0%Con 7D48fc2 4615 6.51
B0%Con 7D48fc3 ......
B0%Con-AV 7D48fcA 3840 6.17
B0%Con-SD 7D48fcS 1096 .48
B0%Con 28D48fc 1 3431 7.8
B0%Con 28D48fc2 3590 8.45
B0%Con 28D48fc3 ......
B0%Con-AV 28D48fcA 3510 8.13
B0%Con-SD 28D48fcS 112.43 0.46
180
Table A.12. Ee and f'e Values for the 50/50 Mix Plus Latex (Vf= 1%)
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Strength (ksi)
B1%S5 1D48fcl 3155.3 4.2
B1%S5 1D48fc2 3101.1 4.5
B 1%S5 1D48fc3 3174.12 4.8
B 1%S5-AV 1D48fcA 3143.51 4.50
B 1%S5-SD 1D48fcS 37.91 0.30
B1%S5 1D612fcl --- 3.08
B1%S5 1D612fc2 --- 3.3
BI%S5-AV 1D612fcA --- 3.19
BI%S5-SD 1D612fcS --- 0.16
B 1%S5 3D48fcl 4089.4 5.9
B 1%S5 3D48fc2 4151.1 5.85
B 1%S5 3D48fc3 4245.45 5.5
B 1%S5-AV 3D48fcA 4161.98 5.75
B I%S5-SD 3D48fcS 78.59 0.22
B 1%S5 7D48fcl 3536.09 5.03
B 1%S5 7D48fc2 3381.81 5.3
B 1%S5 7D48fc3 ......
B 1%S5-AV 7D48fcA 3458.95 5.17
BI%S5-SD 7D48fcS 109.09 0.19
B 1%$5 28D48fc 1 7604.66 6.4
B 1%S5 28D48fc2 8057.87 6.91
B 1%S5 28D48fc3 7385.35 6.05
B I%S5-AV 28D48fcA 7682 6.45
B I%S5-SD 28D48fcS 155.08 0.43
181
Table A.8. Ec and f'c Values for the 30/50 + 50/50 Hybrid Mix (Vf-- 2%)
Mix ID Specimen IT) Elastic Modulus Compressive
(ksi) Strength (ksi)
A2% $3S5 1D48fc 1 2531.32 3.15
A2%S3S5 1D48fc2 2443.66 3.28
A2%S3S5 1D48fc3 2669.8 3.17
A2%S3S5-AV 1D48fcA 2548.26 3.20
A2%S3S5-SD 1D48fcS 114.02 0.07
A2%S3S5 1D612fcl --- 5.08
A2%S3S5 1D612fc2 --- 5.05
A2%S3S5-AV 1D612fcA --- 5.065
A2%S3S5-SD 1D612fcS --- 0.02m i
A2%S3S5 3D48fcl 2805.18 2.97
A2%S3S5 3D48fc2 2767.2 3.83
A2%S3S5 3D48fc3 2883.73 3.34
A2%S3S5-AV 3D48fcA 2818.70 3.38
A2%S3S5-SD 3D48fcS 59.43 0.43
A2%S3S5 7D48fc 1 3305.9 4.66
A2%S3S5 7D48fc2 3447 6.22
A2%S3S5 7D48fc3 3454.23 5.13
A2%S3S5-AV 7D48fcA 3402.38 5.34
A2%S3S5-SD 7D48fcS 83.63 0.80
A2%S3S5 28D48fcl 3563.7 7.77
A2%S3S5 28D48fc2 3315.16 6.1
A2%S3S5 28D48fc3 3492.42 6.86
A2%S3S5-AV 28D48fcA 3457.09 6.91
A2%S3S5-SD 28D48fcS 127.98 0.84
182
Table A.9. Ec and f'c Values for the 30/50 + Polypropylene Hybrid Mix (Vf = 1%)
Mix ID Specimen ID Elastic Modulus Compressive
,, (ksi) Stren[th (ksi)A1%S3P0.5 1D48fc 1 2454.42 3.05
A1%S3P0.5 1D48fc2 2566.42 3.83
A1%S3P0.5 1D48fc3 2435.07 3.26
A1%S3P0.5-AV 1D48fcA 2485.30 3.38
AI%S3P0.5-SD 1D48fcS 70.91 0.40
Al%S3P0.5 1D612fcl --- 3.6
Al%S3P0.5 1D612fc2 --- 3.7
AI%S3P0.5-AV ID612fcA --- 3.65
AI%S3P0.5-SD 1D612fcS --- 0.07
A1%S3P0.5 3D48fc 1 2817.88 3.4
Al%S3P0.5 3D48fc2 2907.86 4.1
Al%S3P0.5 3D48fc3 2855.06 4.1
AI%S3P0.5-AV 3D48fcA 2860.27 3.87i t
AI%S3P0.5-SD 3D48fcS 45.22 0.40
Al%S3P0.5 7D48fcl 3215.7 5.03
A 1%S31:'0.5 7D48fc2 3007.7 4.7
A 1%S3P0.5 7D48fc3 2911.77 3.68
AI%S3P0.5-AV 7D48fcA 3045.06 4.47
AI%S3P0.5-SD 7D48fcS 155.37 0.70
A 1%S3P0.5 28D48fc 1 2611.7 4.76i
A 1%S3P0.5 28D48fc2 2764.5 5.11
A1%S3P0.5 28D48fc3 2742.01 4.84
AI%S3P0.5-AV 28D48fcA 2706.07 4.90
AI%S3P0.5-SD 28D48feS 82.50 0.18
183
Table A.13. Ec and f'c Values for the Polypropylene Mix Plus Latex (Vf = 1%)
Mix ID Specimen 1]) Elastic Modulus Compressive
(ksi) Strength (ksi)B 1%P0.5 1D48fc 1 2279.24 2.65
B 1%P0.5 1D48fc2 2492.11 3.15
B 1%P0.5 1D48fc3 2025.97 3
B 1%P0.5-AV 1D48fcA 2265.77 2.93
B 1%P0.5-SD 1D48fcS 233.36 0.26
Bl%P0.5 1D612fcl --- 3
B 1%P0.5 1D612fc2 --- 3.1
B 1%P0.5-AV 1D612fcA --- 3.05
B 1%P0.5-S D 1D612fcS --- 0.07
B 1%P0.5 3D48fc 1 2665.7 4
B 1%P0.5 3D48fc2 2816.82 4.4
B 1%P0.5 3D48fc3 2901.42 4.52
B 1%P0.5-AV 3D48fcA 2794.65 4.31
B 1%P0.5-SD 3D48fcS 119.41 0.27
B 1%P0.5 7D48fc 1 2764.12 3.5
B 1%P0.5 7D48fc2 2992.4 4.7
B 1%P0.5 7D48fc3 2816.86 5.2
B 1%P0.5-AV 7D48fcA 2857.79 4.47
B 1%P0.5-SD 7D48fcS 119.52 0.87
B 1%P0.5 28D48fc 1 6211 5.5
B 1%P0.5 28D48fc2 6623.5 5.52
B 1%P0.5 28D48fc3 6965.6 6.35
B 1%P0.5-AV 28D48fcA 6600.03 5.79
B 1%P0.5-SD 28D48fcS 377.85 0.49
184
Table A.14. Ec and f'c Values for the 50/50 Mix Plus Silica Fume (Vf = 1%)
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Strength (ksi)
C 1%S5 1D48fc 1 3763.57 5.38
C1%$5 1D48fc2 3806.61 5.61
C1%S5 1D48fc3 3404.84 5.38
CI%S5-AV 1D48fcA 3658.34 5.46
CI%S5-SD 1D48fcS 220.59 0.13
C1%$5 1D612fcl --- 5.03
C1%S5 1D612fc2 --- 5.8
CI%S5-AV 1D612fcA --- 5.415
CI%S5-SD 1D612fcS --- 0.54
C1%S5 3D48fc 1 2036.43 5.6
C1%$5 3D48fc2 2011.29 5.7
C1%$5 3D48fc3 1870.92 6.4
C 1%S5-AV 3D48fcA 1972.88 5.90
C1% S5-SD 3D48fcS 89.19 0.44
C1%$5 7D48fcl 4004.7 7.1
C1%$5 7D48fc2 4184.2 8
C1%S5 7D48fc3 ......
C1%S5-AV 7D48fcA 4094.45 7.55
CI%S5-SD 7D48fcS 126.93 0.64
C 1%S5 28D48 fc 1 2782.5 9.05
C 1%S5 28D48fc2 2171.09 7.75
C1%$5 28D48fc3 ......
C 1%S5-AV 28D48fcA 2476.80 8.40
C1%S5-SD 28D48fcS 432.33 0.92
185
Table A.15. Ee and f'c Values for the Polypropylene Mix Plus Silica Fume(Vr= 1%)
Mix ID Specimen 113 Elastic Modulus Compressive
(ksi) Strength (ksi)
C 1%P0.5 1D48fc 1 2843.23 3.3
C1%P0.5 1D48fc2 2876.49 3.2
C 1%P0.5 1D48 fc3 2719.45 3.85
C1%P0.5-AV 1D48fcA 2813.06 3.45
CI%P0.5-SD 1D48fcS 82.75 0.35
Cl%P0.5 1D612fcl --- 4
Cl%P0.5 1D612fc2 --- 3.8
CI%P0.5-AV 1D612fcA --- 3.9
CI%P0.5-SD 1D612fcS --- 0.14
C 1%P0.5 3D48fc 1 3635.99 5.5
C 1%P0.5 3D48fc2 3490.99 5.65
Cl%P0.5 3D48fc3 3783.55 3.27
C 1%P0.5-AV 3D48fcA 3636.84 4.81
C1%P0.5-SD 3D48fcS 146.28 1.33
C 1%P0.5 7D48fc 1 3512.42 5.3
C1%P0.5 7D48fc2 3414.59 6.01
C1%P0.5 7D48fc3 3234.7 5.43
C1%P0.5-AV 7D48fcA 3387.24 5.58
C1%P0.5-SD 7D48fcS 140.87 0.38
Cl%P0.5 28D48fcl 2880.3 4.93
Cl%P0.5 28D48fc2 2993 6.21
C1%P0.5 28D48fc3 2897.75 6.53
C1%P0.5-AV 28D48fcA 2923.68 5.89
CI%P0.5-SD 28D48fcS 60.66 0.85
186
Table A.16. Ec and f'c Values for the 30/50 + 50/50 Hybrid Mix Plus SilicaFume (Vf = 1%)
Mix ID Specimen ID Elastic Modulus Compressive
(ksi) Strength (ksi)
C1%S3S5 1D48fcl 3226.78 4.5
C1%S3S5 1D48fc2 3365.8 4.93
C 1%S3S5 1D48fc3 3257.4 4.92
CI%S3S5-AV 1D48fcA 3283.33 4.78
CI%S3S5-SD 1D48fcS 73.05 0.25
C1%$3S5 1D612fcl --- 4.6
C1%$3S5 1D612fc2 --- 4.75
CI%S3S5-AV 1D612fcA --- 4.675
CI%S3S5-SD 1D612fcS --- 0.11
C1%S3S5 3D48fc 1 4288.15 5.54
C1%S3S5 3D48fc2 4320 5.61
C1%S3S5 3D48fc3 4154.01 5.32
C1%S3S5-AV 3D48fcA 4254.05 5.49
CI%S3S5-SD 3D48fcS 88.09 0.15
C 1%S3S5 7D48fc 1 3422 7.03
C1%$3S5 7D48fc2 3549 7.83
C1%$3S5 7D48fc3 3370.08 7.15
C1%S3S5-AV 7D48fcA 3447.03 7.34
C1%S3S5-SD 7D48fcS 92.05 0.43
CI%$3S5 28D48fcl 2872.3 8.11
C1%$3S5 28D48fc2 3318.2 7.32
C 1%S3S 5 28D48fc3 3422.25 6.76
CI%S3S5-AV 28D48fcA 3204.25 7.40
CI%S3S5-SD 28D48fcS 292.15 0.68
187
FRC - Test: a¢ ! day- Controt HIxm
- Cylinder- size, 4" x 8'
U1 u5 , Average Curve___'J It I
;I• rl I
(/) _r ',I t
LLJ _,
I
i' ii i• i
• I ""1 I._ 1 1 I 1 1 !!
.00 .01 .02 .03 .04 .05 .06
STRAIN
Fig. A.1 - Stress vs. Strain Response of Control Mix, 1 Day, 4"x 8" Cylinders
FRC - Tes¢ a¢ 3 days
,, Cont:rot Mix
Cylinder size, 4' x 8'
__ I_ Average Cumve%J
UJrv_p-
:f,00 ,01 ,02 ..03 ,04 ,05 ,06
STRAIN
Fig. A.2 - Stress vs. Strain Response of Control Mix, 3 Days, 4"x 8" Cylinders
188
,00 .01 .02 .03 .04 .05 .06
STRAIM
Fig. A.3 - Stress vs. Strain Response of Control Mix, 7 Days, 4"x 8" Cylinders
o_
o5 F'RC- Tes1: (;t: 28 daysCon'trot Mix
r,iCytlnder" size, 4' x 8'
y, Average Curvevu i(/)(/) .ILl '¢rv
.00 ,01 .02 .03 ,04 ,05 .06
STRAIN
Fig. A.4 - Stress vs. Strain Response of Control Mix, 28 Days, 4"x 8" Cylinders
189
_f FRC - Test at I dr,y
30/50 Hooked Fibers, t/d=60VF = I_.(oF Conc're'te)
Cytlnder size, 4' x 8'
N
M
.00 .01 .02 .03 .04 .05 .06
STRAIN
Fig. A.5 - Stress vs. Strain Response of A1%S3,1 Day, 4"x 8" Cylinders
/• I'- F'RC - Test ¢L't 3 d_ys
r,,.r- . 30/50 Hooked Fiber-s, |/d=60
._- /_, VF = lY. ( oF Concr'e,e)
,.o_ :f ;'_,. Ct,jtlnder size, 4' x 8'
.00 .01 .0;_ .03 .04 .05 .06
STRAIH
Fig.A.6 - Stressvs.Strain Responseof A1%S3,3 Days,4"x 8" Cylinders
190
t.
FRC - Tes_ o"k ;7 doysrC ,, 30/50 Hooked Fibers, t/d=60
Vf = 1:/.( oF Concrete)
Cylinder size, 4' x 8'
ui Averoge Curve.X '.
wr_ l ' ,i-- , ",, F,
•..... '+, o..,,,.s
.00 .01 .0;:' ,03 .04 .05 .06
STRAIN
Fig. A.7 - Stress vs. Strain Response of A1%S3,7 Days, 4"x 8" Cylinders
o_m
. FRC - Tes+ o't 28 cloysco 30/50 Hooked Fibers, t/d=60
rC VF = W. ( oF Concrete)Cytlnder size, 4' x 8'
m _
v_ _ Averooe Curveui
O0C_L_ry
(/)r_ ,,rt_
', %,bi
.
.OO .01 .O@ .03 .04 .05 .06
STRAIM
Fig. A.8 - Stress vs. Strain Response of AI %S3,28 Days, 4"x 8" Cylinders
191
_f F'RC - Test ot; t d;y
30/50 Hooked Fibers, t/d=60VF = 2_. ( oF Concre*e)
,, Cylinder size, 4" x 8"
UI Iri- 'I__' ", Aver'G,e Cur-reV -- ff |ltltt_ i,
(,4_:- _"_, ",.
ry ei- '",', '",,i *, "l t
_ b L_
,..,_I I I I I I I I I I I.00 .01 .OEZ .03 .04 .05 .06
STRAIM
Fig. A.9 - Stress vs. Strain Response of A2%S3,1 Day, 4"x 8" Cylinders
/._ .. FRC - Tes't a't 3 daws
h E ;'_, 30/50 Hooked Fibers, I./d=60I :I.,,_;,, vf l eX ( Or Corlcr'_e"_e)
Cy==d,,-,,de,,'x e'
*t i
ww : ,2:,
.00 .01 .0::) .03 .04 .05 .06
STRAIN
Fig. A.10 - Stressvs. StrainResponseof A2%S3,3 Days,4"x 8" Cylinders
192
oi
FRC - Test at 7 days30/50 Hooked Fiber's, t/d=60
',, VF = 2?, ( oF Concrete),_ Cy|lnder size, 4' x 8'
Uly u5 AverQge CurveV
(/) _:-
W -rwH_
I-- "_.
.00 .Or .02 ,03 .04 .05 .06
STRAIH
Fig. A.11 - Stress vs. Strain Response of A2%S3,7 Days, 4"x 8" Cylinders
o_
FRC - Test at 28 d,_ys"t'_ 30/50 Hooked Fibers, t/d=60
Vf = 2_. ( oF Concrete)r_ r,
Cytlnder"slze, 4' x 8'
__ Aver'Qge Curve
vu5 _,mt
(/) I_L,J_Fryp-
it,V,T_II,.,.
.00 ,01 .02 ,03 .04 .05 .06
STRAIPI
Fig. A.12 - Stress vs. Strain Response of A2%S3,28 Days, 4"x 8" Cylinders
193
cL
- F'RC - Tes't cL_cI day- 50/50 Hooked Fibers, [/d-lO0- VF = 1_. ( oF Concrel:e)
,_ - Cylinder size, 4' x 8'
.00 .01 ,02 .03 .04 ,08 .06STRAIM
Fig. A.13 - Stress vs. Strain Response of AI%SS, 1 Day, 4"x 8" Cylinders
_f F'RC - Test; Qt; :3 days
50/50 Hooked Fibers, t/d:lO0VF --- 1_. ( of Concre'te)
_v -- /'''''" Cylinder size, 4' x 8'u')" ;' '*,. Aver-age Curve! t
I I
! I
.00 .01 .OP .03 .04 .05 .06
STRAIM
Fig. A.14 - Stress vs. Strain Response of A1%S5,3 Days, 4"x 8" Cylinders
194
0o
FRC - Test at 7 days
50/50 Hooked Fibers, [/d=lO0
VP = ;Y, ( oF Concrete)
CyLinder size, 4' x 8'
U) ui Average CurveY
(/) t"
i,i
_,:_ "%,
• v1_" .
' _'_i,o1.,pf ..
,00 .01 .02 ,03 ,04 .05 .06
STRAIM
Fig. A.15 - Stress vs. Strain Response of A1%S5,7 Days, 4"x 8" Cylinders
o; /.I- FRC - Test Qt 88 days
®L_ so/soHookedFibers,t/d=lO0r-
I- VF = IX.( oF Concrete)
h i- ,4,:,, CyLinder size, 4' x 8"
o i Itu')l- ,I,' _\ ',
,00 .01 .08 .03 .04 .05 .06
STRAIN
Fig. A.16 - Stress vs. Strain Response of A1%S5,28 Days, 4"x 8" Cylinders
195
co
FRC - Test at I day
r_- 3/4' PolupropyteneF'Ibers- VP = 1X ( oF Concrete)
,3- Cytlnderslze,4' x 8'
..__- Aver,,geCurvem
bJ
h-ntri ' ",
J i I I I I I I I I I.00 .01 .02 ,03 .04 .05 .06
STRAIM
Fig. A.17 - Stress vs. Strain Response of AI%P0.75,1 Day, 4"x 8" Cylinders
. FRC - Test at 3 days3/4' Potupropytene Fibers
- VF = IX ( o# Concrete)
- CyLinder size, 4' x 8'
y _ Average CurveV
oo_
1J
nzeih"°t.L
LI
I I I I I -'1...... i..... .I I I I.00 .01 .08 .03 .04 ,05 ,06
STRAIM
Fig. A.18 - Stressvs. StrainResponseof AI%P0.75,3 Days,4"x 8" Cylinders
196
_| L FRC - Test at 7 days
E 3/4' PotypropyLene FibersVF = 17. ( oF Concrete)
,, Cytmder size, 4' x 8'
_ I _ AverQge CurveYV
(/)
rYt_ _,(/)
(_ b,/i . •
I ll_
".t*. •
I I I i I ! I I I I I,00 .01 .02 .03 ,04 .05 .06
STRAIH
Fig. A.19 - Stress vs. Strain Response of Al%P0.75,7 Days, 4"x 8" Cylinders
FRC - Test Qt P8 d_ys
r( L 3/4' Po|ypropytene Fibers-L VF = i?. { oF Concrete)
_F , CyLinder size, 4' x 8'
_c,i : ','
iI I_I_ • %"t
.00 .01 .08 .03 .04 .05 .06
STRAIH
Fig. A.20 - Stress vs. Strain Response of Al%P0.75,28 Days, 4"x 8" Cylinders
197
m
FRC - Tes't at 1 dayr_.- 3/4' Po|t,jpropytene Fibers
- VF = 2_. ( of Concre'te)
,_- Ctjtlnder size. 4' x 8'
m__Cui- Average CurveV m
(_-
bJ "
n, _ ,,_,
. ' P, t.. t.
_:_" I I I I I I.00 .Or .02 .03 .04 .05 ,06
STRAIN
Fig. A.21 - Stress vs. Strain Response of A2%P0.75,1 Day, 4"x 8" Cylinders
°
m. - F'RC- Tes'_ at 3 d_ysr,, - 3/4' Pottjpropytene Fibers
- VF = PX ( oF Concre'te)
'_ - Cy|lnder size. 4" x 8'
v_Ui Average Curve• II tI
.b/t;
.00 .0! .02 .03 .04 .05 .06
STRAIM
Fig. A.22 - Stress vs. Strain Response of A2 %P0.75,3 Days, 4"x 8" Cylinders
198
0_
- F'RC- Tes'¢ at 7 dQujsr_- 3/4' Polypropt,jiene Fibers
- Vf = 2_. ( oF Concre'te)
q)" CyLinder size. 4" x 8'
_- ,',, Average Curveu5
I.* It
l_c,i i '.
",. ',,....
.UO .01 .02 .03 ,04 .05 .0(
STRAIM
Fig. A.23 - Stress vs. Strain Response of A2%P0.75,7 Days, 4"x 8" Cylinders
m
F'RC- Tes't: _'t 88 d,,ys3/4' Polypropytene Fibers
VF = ;_Y. ( oF Concre'te)
q) - Ct,jtlnder size, 4' x 8'
y _ - , --Averoge Curve
v ',
t tt I
I-'_ "_,',_ 2"."; / "'"-2.2.22-:.2. I " F, i --'-_-" '"- - l l I.00 .01 .OP .03 .04 .05 .06
STRAIM
Fig. A.24 - Stress vs. Strain Response of A2%P0.75,28 Days, 4"x 8" Cylinders
199
- FRC - Test at I day
- Hybrld Hlx
- 30/50 + 50/50 Hooked Flbers
- ," VF = 1% ( oF Concrete)
==_ m . •In I-- il_s'_"_;- Cylinder size, 4' )( 8'
I- ;F,1:'_!_J',, _ Average Curve.1 ,i: !-:J_'i',,
_ _'r- _1; "_th_'l,,
:1: ,,,,%r;,t
• '','i'l ,..
2....,00 .Or 32 .03 .04 ,05 .06
STRAIFI
Fig. A.25 - Stress vs. Strain Response of A1%S3S5,1 Day, 4"x 8" Cylinders
o
_f FRC - Test at 3: da_jsH_Jbrld HIx30/50 + 50/50 Hooked Fibers
'i" Vf = 1% ( o? Concrete)i f
:; '., C_jtlnder slzel 4' X 8 l
" [,,_ _, _ Average CurveI f
i
_ _ " "i_"I I t,
I I
I!
I I I I I I I ..... 1..... I I I,00 .Ot ,OP .03 .04 ,05 36
STRAIM
Fig. A.26 - Stressvs. StrainResponseof AI%S3S5,3 Days,4"x 8" Cylinders
200
o5
', FRC - Test at 7 daysr_ Hybrid Mix
30/50 + 50/50 Hooked FibersVF = IX ( o_ Concre_¢e)
._ L
V)__ _ Cylinderslze,4" x 8'v Average Curve
C_bJr_e_p-
,,
,00 .01 .02 .03 ,04 .05 .06
STRAIH
Fig. A.27. Stress vs. Strain Response of AI%S3S5,7 Days, 4"x 8" Cylinders
o5
FRC - Test at 28 dags
: ', Hujbrld Mix
"30/50 + 50/50 Hooked FibersVf = 1X ( o_ Concrete)
INtA ,'_,,_ Cylinder size, 4' x 8', ,, , Average Curve
"-".... :222"
.00 .01 ,02 .03 ,04 .05 .06
STRAIH
Fig. A.28 - Stress vs. Strain Response of A1%S3S5,28 Days, 4"x 8" Cylinders
201
00
.- FRC - Test Qt 1 d_j
- Hybrid HIx
- 30/50 + 50/50 Hooked Fibers
- VF = 2_ ( oF Concrete)
_- Cgtlnder size# 4' x e'v _ ,., Average Curve
,00 .01 ,OP .03 .04 ,05 .06
STRAIH
Fig. A.29 - Stress vs. Strain Response of A2 %S3S5,1 Day, 4"x 8" Cylinders
o5
FRC - Test =± 3 d=ysP_ Hybrid HIx
30/50 + 50/50 Hooked Fibers
VF = 27. ( oF Concrete)
y It_ C_jtlnder slze_ 4" x 8'v _ Average Curve
I.I , "
I"- .i.t-,'_';""
plI
.00 .01 ,OP ,03 ,04 ,05 ,06
3TRAIh
Fig. A.30 - Stress vs. Strain Response ofA2%S3S5,3 Days, 4"x 8" Cylinders
202
OO
-- FRC - Tes_ o¢ ;7 dogs
- Hybrid HIx30/50 + 50/50 Hooked Fibers
q)- ,, ', VP = 1_. (o_ Concrete)
U_r- _ ,_. Cgtlnder slzeJ 4' x 8'
',,, ,.,_ -- Averoge Curve_'¢- i
I I I I I I iI/ I I I I
.00 ,01 .02 .03 .04 .05 .06
STRAIM
Fig. A.31 - Stress vs. Strain Response of A2%S3S5,7 Days, 4"x 8" Cylinders
o
'' FRC - Tes_ a'_ 28 dogs
,, Hybrid Mix•' 30._50 + 50/50 Hooked FIIoer_
VF = 27. ( oF Concrete)i
.__ _ ., CgUnder size, 4' x 8'i
"-" " -- Averoge Curve
rv'e_ , ,,
.i
.00 .01 .OP .03 .04 .05 .06
STRAIH
Fig. A.32 - Stress vs. Strain Response of A2%S3S5,28 Days, 4"x 8" Cylinders
203
0d
FRC - Tes'ta'tI d,,y
r_ HybridHlx3/4' Potypropyiene+
',o 30/50 Hooked Fibers,VF = 1%
__s_ Cytlnder size, 4' x B'Average Curve
fti _,
t
,00 ,01 ,02 ,03 .04 .05 .06
STRAIN
Fig. A.33 - Stress vs. Strain Response of A I %S3P0.7_:, 1 Day, 4"x 8" Cylinders
FRC - Test nt 3 days
HybrldHIx3/4' Potypropytene+30/50 Hooked Fibers, VF = 1%
V_ _ Cylinder size, 4' x 8"
v _ Average Curve
C,qbJ
rvr_ '_7,.-,.p-
.00 .01 ,OP .03 .04 .05 .06
STRAII'i
Fig. A.34 - Stressvs. StrainResponseof Al%S3P0.75,3 Days,4"x 8" Cylinders
204
o_
- FRC - Test _ 7 d_ys- Hybrid Mix- 3/4' Potypropylene +- 30/50 Hooked Fibers. V_ = 1_.
u_.- ,,,, Cylinder size, 4' x 8'L ,,7,,, __ Averoge Curve
. I _
.00 .01 .02 .03 .04 .05 .06
STRAIrl
Fig. A.35 - Stress vs. Strain Response of Al%S3P0.75,7 Days, 4"x 8" Cylinders
- FRC - Tes± Qt 28 d_ys
- Hybrid Mlx
.- 3/4' Potgpropytene +
- 30/50 Hooked Fibers, VF = I_.
_ _1-,', Cytlnder size, 4' x 8'__,v.,°oocoov.
.00 .01 .02 .03 .04 .05 .06
STRAIN
Fig.A.36. Stressvs.StrainResponseofAl%S3P0.75,28Days,4"x8" Cylinders
205
o_
- FRC - Test at I day
- HybridM;x- 3/4" Potgpropyiene +
- 30/50 Hooked Fibers VF ='.27.
I_- ,-, Cylinder size, 4' x 8
I- ,"/_:_', __ A_er=Oecurve
_ ' ,
_i _ ',
.00 .01 .02 .03 .04 .05 .06
STRAIN
Fig. A.37 - Stress vs. Strain Response of AZ%S3P0.75, I Day, 4"x 8" Cylinders
m
FRC - Test ot 3 days
Hybrid Mix
- 3/4' Pot_prop_jtene +
- 30/50 Hooked Fibers, VF = 2?.S'%
m_i- _,__ , Cylinder size, 4' x 8'
v - |,'__ _',,,, ..__ Pwer_ge Curve(/)_: - ,,
I.,.I- _ ', ,,n'e__ , .,l--
";I .....-""'-, I I I I i /..... I I I I I.00 .01 .0;:) .03 .04 .05 .06
STRAIN
Fig. A.38 - Stress vs. Strain Response of A2%S3P0.75,3 Days, 4"x 8" Cylinders
206
o5
FRC - Test at 7 days
r_ HybPId HIx
,,,, 3/4' Polypr,opytene +q)--
,,"_ ', 30/50 Hooked Fiber,s, VF = 2_.t" t_
__ , Cylinder` size, 4' x 8'
"-" / "_,:_., _ Average Cur,ve(/) _: ',4
ry _ :; ', ',II t. #.
iI
I ! I I 1 I / ..... r_-:-I I 1.00 .0! .02 .03 .04 .05 .06
STRAIH
Fig. A.39 - Stressvs.StrainResponseof A2%S3P0.75,7 Days,4"x 8" Cylinders
if FRC - Test a't 28 da';.JS
Hybrid HIx
3/4' Pot_jpropytene +
"Dr"[_ _'l_" 30/50 Hooked Fiber,s, VF = PZ}u5!'- _ C_jtOndersize, 4' x S'
_ , _ _ Aver'aoeCur,ve(,,,)
_ r6 '""
.00 .OI ,02 .03 .04 .05 .06
STRAIFI
Fig.A.40 - Stressvs. StrainResponseof A2%S3P0.75,28 Days,4"x 8" Cylinders
207
cOm
F'RC - Tes4; aLt: I d_t,j
r(- I.a'tex HIx
- 50/50 Hooked $'t:ee| Fibers
,_- VF = I?.
i- Cylinder size, 4' < 8'
I- ,"_" Avera.eCurve
° s.
,.,
.00 .01 ,OP ,03 .04 .05 ,06
STRAIM
Fig. A.41 - Stress vs. Strain Response of B1%S5,1 Day,, 4"x 8" Cylinders
°
_f F'RC - Tes't QI: 3 days
LQ'tex HIx
50,,'_0 Hooked S'teet Fibers
VF = l?.
U') Ct,jtlnder slzet 4" x 8"AverQge Curve
-'2"
t _ I I I I I I ,! I I.00 .01 .02 .03 .04 .05 .06
STRAIDI
Fig. A.42 - Stress vs. Strain Response of B1%S5,3 Days, 4"x 8" Cylinders
208
.- FRC - Tes_ _ ? dQys- Latex HIx- 50/50 Hooked $_ee| Fibers- VF = 17.
I I I I I I I I I I I
.00 .01 .02 ,03 .04 .05 .06
STRAIM
Fig. A.43 . Stress vs. Strain Response ofBl%S$, 7 Days, 4"x 8" Cylinders
°
GO
FRC - Tes_ a_ 88 d_ysr_ . Latex HIx
50/50 Hooked Steer Fibers
._ _ ,, ,, Cylinder size, 4' x 8'V _ 1
•, AverQge Curve
r_F ,,,, ,,(/) _,Ld " ', "£v _I--
..'-'-.'-'.-.-- ......
.00 .01 .OE ,03 ,04 .05 .06
STRAIM
Fig. A.44 - Stressvs. StrainResponseof B1%SS, 28 Days,4"x 8" Cylinders
209
co
FRC - Test at 1 day- Latex Mix
- 1/2' Potypropytene Fibers"_- VF = IZ
__ Irii Cylinder size, 4" x 8'
) - Average CurveB
.00 .01 .OE .03 .04 .05 .06
STRAIN
Fig. A.45 - Stress vs. Strain Response of Bl%P0.5,1 Day, 4"x 8" Cylinders
m
FRC - Test at 3 daysr_ m Latex Mix
1/2' Potyprop_j|ene Fibers,,6- VF : 1_.
i-iri CI,j|lnder size, 4' x 8'
r- ,-, Average Curve
+i- ih_
<"<,il-f ,_,,,
,00 .or .02 ,03 ,04 .05 .06
STRAIPI
Fig. A.46 - Stress vs. Strain Response ofBl%P0.5,3 Days, 4"x 8" Cylinders
210
0o
F'RC- Test _t 7 d,,ysr_- LQ'tex HIx
- 1/2' Potypr'opytene F'lber,s"0 - Vf' = 1_
Ul.._ _ - ,', Cy|lhder size, 4' x 8'v " ' Aver,age Curve
F-
i l I I I I I I I I I.00 .01 .08 .03 .04 .05 .0(=
STRAIH
Fig. A.47 - Stress vs. Strain Response of Bl%P0.5,7 Days, 4"x 8" Cylinders
f IrRC - Test at 28 daysI< Latex Mix
• 1/2' Polypr'opytene FIber,s;' Vf' = W.
y _ Cylinder` size, 4" x 8'
v Aver'age Curve(_:
L,Jn,'e, iI--
' f I i I I I I I I I I.00 .01 .08 .03 .04 .05 .06
STRAIH
Fig. A.48 - Stress vs. Strain Response of B1%1)0.5,28 Days, 4"x 8" Cylinders
211
cJ
O_- FRC - Test a_: 1 day- Lttex Mix
o_- VF=O
v Cylinder size, 4" x 8"
I I" I.....i....._.....L.... I . I I I I
.00 .01 ,02 .03 ,04 .05 .06
STRAIH
Fig. A.49 - Stress vs. Strain Response of B0%CON, 1 Day, 4"x 8" Cylinders
D
o_- f'RC - Tes_c _t 3 d_js- Lo'tex Mix
o6- VF=0
I ,v. oo.
ai ,,'
,00 ,01 ,02 ,03 ,04 ,05 ,06
STRAIH
Fig. A.50 - Stress vs. Strain ResponseofB0%CON, 3 Days, 4"x 8" Cylinders
212
c_m
o_ - FRC - Test Qt 7 d=ys- Latex Nix
(_- VF=O
I_ -_ _ it
v Cylinder size, 4' x 8'/
V) ui ',, Average(_) le#iJl
LIJ lit.
nt_I--_'_i ,
F
i I I I I I I I I I I.00 .01 .02 .03 .04 .05 .06
STRAIM
Fig. A.51 - Stress vs. Strain Response ofB0%CON, 7 Days, 4"x 8" Cylinders
B
o_ FRC - Test at ;)8 dQ_js
, LQ_cex Mixo_ /j VF=0
r< _'__i Cylinder size, 4' x 8"
(_ ui / _ AverQge,
iiI.
It
P !
I '_ I I I I I I I I I I.00 .01 .02 .03 .04 .05 .06
STRAIH
Fig. A.52 - Stressvs.Strain Responseof B0%CON, 28 Days, 4"x 8" Cylinders
213
a_
FRC - Test Qt ! dayr_- SltlcQ Fume Mix
- 50/50 Hooked Fibers
- VF = I_.m l_
tn _',."',.__ _ /,, _',, Cytlnder size, 4' >: 8'v ____ Average Curve
(/)
L_rv ',_'
g-I
1 I I I I I.00 .01 .02 .03 ,04 .05 .06
STRAIH
Fig. A.53 - Stress vs. Strain Response of C1%$5,1 Day, 4"x 8" Cylinders
a_
_f FRC - Test (st 3 days
SILica Fume HIx
- 50/50 Hooked Fibersi ! I L
I-i'l,_ _. c_.,,dors,-e,4' ,_e'1-:It _... __ AveraQeCurv,
.00 .01 .02 .03 .04 .05 .06
STRAIM
Fig. A.54 - Stressvs. StrainResponseof C1%$5,3 Days,4"x 8" Cylinders
214
/
-_ FRC - Tes_ a_ ? dG_jsoo. ,", SI(Ic_ Fume HIx
"f /_'li_/" 50/50VF= 17.Ho°ked Fibers
r_
,- "F il/ :',,, C_t.,,ders.-e.4'x ."_1- :i_ ,_ __ Aver,OeCurve
)I/ \_ : .!'! I; y
_(_ t") 'l '-"
-- _ir i i I I 1,I I I I I I
.00 .01 .02 .03 .04 .05 .06
STRAIM
Fig. A.55 - Stress vs. Strain Response of C1%$5,7 Days, 4"x 8" Cylinders
o_
o_ FRC - Tes_c _ 28 days$1llc:a Fume Mix
50/50 Hooked FibersVF = 1;':.
j-%
__ Cylinder size, 4' x 8'
v Ui Average Curve_q_qLd_n¢
II _4.
.00 .01 .02 .03 .04 .05 .06
STRAIH
Fig. A.56 - Stress vs. Strain Response of C1%$5,28 Days, 4"x 8" Cylinders
215
a_
- FRC - Tes_¢_t; I dc_yr_ - SItlca Fume HIx
- 3/4' Polypropytene Fiber's
u'i - Cytlnder-size, 4" x 8"- -_ Aver-Qge Curve
FiAi '
. I I
.00 .0! .02 .03 .04 .05 .06
STRAIH
Fig. A.57 - Stress vs. Strain Response of C1%P0.75,1 Day, 4"x 8" Cylinders
.
_t FRC - Tese _¢ 3 days_;Itlce Fume HIx
3/4' Potypropytene Fibers
tn ,:_y _- ,,_* C_jtlndeP size, 4' x 8'v - '_ Averoge Cur.re
(/J
,.,-ry __ r,l,l,,J,-, '
(/') -i ' 'I
I I "f'" I I I I I I I I
.00 .0! .02 .03 .04 .05 .06
STRAIH
Fig. A.58 - Stress vs. Strain Response of C1%P0."15,3 Days, 4"x 8" Cylinders
216
0_
F'RC- Tes'l: o_ ;' doysr_ SILica Ful_e Hlx
3/4' PoL_jprop_tenePlbersVF = l?.
tn__ u_ Cytlnder size, 4' x 8'v _ Average Curve
",, _q ,q..
.00 .01 .02 .03 .04 ,05 .06
STRAIN
Fig. A.59 - Stress vs. Strain Response of C1%P0.75, "7Days, 4"x 8" Cylinders
F.RC- Tesl: at: P8 daysSilica F.umeHIx
,' I/2' Potypr'op_tene F.ibersVf = 17.
tny u'J . CyLinder"size, 4' x 8'v , Average Curve
I
(_L,.I ',I---
.00 .Ol .OP .03 .04 .05 .06
STRAIN
Fig. A.60 - Stress vs. Strain Response of C1%P0.5,28 Days, 4"x 8" Cylinders
217
FRC - Test at 1 dayrK-
._;l|lca FuMe Hybrid Mix- :]0/50 + 50/50 Hooked Fibers- VF = IZ
f%,°I
IP _ '_ C_jtlnder size, 4" x 8'"J '_, Average Curve
(/)
._
I I I I I I I I 1 I I•00 .01 .02 .03 ,04 .05 .06
STRAIH
Fig. A.61 - Stress vs. Strain Response of CI%S3SS, 1 Day, 4"x 8" Cylinders
f FRC - Test at 3 d_t,jsr( $1LIcQFume Hybrid HIx
30/50 + 50/50 Hooked Fiberso
,,D Vt" = 1_.it f I
__ I_ C_j|lnder size, 4" x 8"'_' I,' _'_e',, _ Average Curve
" i! I _t I t
I I. I
°
I I I I I ""1" I I I I I,00 .01 .0_ ,03 .04 .05 .06
STRAIH
Fig. A.62 - Stressvs. Strain Responseof C1%$3S$, 3 Days, 4"x 8" Cylinders
218
tlf t
FRC - Test Qt 7 d_ys
r_ SILIcG Fume Hybrid HIx
, 30/50 + 50/50 Hooked Fibers
" VF = W.
I ui ,, CyLinder size, 4' x 8'V
,, Average Curve
Ld l -n¢ _i ° ,, ,.I-- '
.00 ,01 .02 .03 .04 .05 .06
STRATN
Fig. A.63 - Stress vs. Strain Response of C1%$3S5,7 Days, 4"x 8" Cylinders
oo "i. - '-.' IrRC - Test at 28 d_gs
I_- _I_ Sitlc_ Fume H_jbrld Hlx
. - li_ , 30/50 + 50/50 Hooked Fibers
ul - ,, C_jtlnder" sizes 4' x 8'
- i_t', Average Curve
!\
(_ _: ,, ",,
N l ', , "..
.00 .01 .02 .03 .04 .05 .06
STRAIM
Fig.A._;- Stressvs.StrainResponseofCI%$3S5,:38Days,4"x8"Cylinders
219
OD
FRC - Test Qt I d_yr_-ControlMlx
- Cgtlnderslze,6' × 12'
I_- AverQge Curveii
,}. f I
l; I LLd ',,nt _,i-i_" f E0'1 ,
I ; ii_ "J I I f
JI;I
"I l I l I I I I I l l,00 .01 ,02 ,03 ,04 .05 ,06
STRAIN
Fig. A.65 - Stress vs. Strain Response of Control Mix, 1 Day, 6"x 12" Cylinders
°J LL FRC - Test =t I dcxt,j
r_ L 30/50 Hooked Fiber's, L/d=60
.[- VF = 1_.( oF Concrete)
_OF ,', Cylinder size, 6' x 12'
_ ___i__L' Aver'Goe CUrVe
.00 .01 .0;_ .03 .04 .05 .06
STRAIH
Fig. A.66 - Stress vs. Strain Response of A1%S3, 1 Day, 6"x 12" Cylinders
220
cd
FRC - Test (;± I d_y
i_- 30/50 Hooked Fibers, L/d=60- Vf = 27. ( oT" Concrete)
- Cytlnder size, 6' x 12'
__ ui- ," AverQge Curve
f• t
.00 .01 .02 .03 .04 .05 .06
STRAIN
Fig.A.67- Stressvs.StrainResponseofA2%S3,1 Day,6"x12"Cylinders
_f FRC - Test 0"¢I doL_J
50/50 Hooked Fibers, t/d=100Ve" = 17. (oF Concrete)
2, C_jUndersize, 6' x IP'm /
i ,l I
i
M f
.00 .01 .0P .03 .04 .05 .06
STRAIIH
Fig. A.68 - Stress vs. Strain Response of A1%S$, 1 Day, 6"x 12" Cylinders
221
co
.- F'RC - Test Qt I d,,yr%. - i
3/4 Poh,jpropytene Fibers
- VF = I_.(oF Concrete)
- CyLinder size, 6' x 12'
u_ - - Average Curve
\."'1 I I I I I I I _
.00 .01 .02 .03 .04 .05 .06
STRAIN
Fig. A.69 - Stress vs. Strain Response of AI%P0.75, ! Day, 6"x 12" Cylinders
o_I
FRC - Test Qt 1, day
K- 3/4' Polypropytene Fibers
- VF = 2_. (oF Concrete)
-- Cylinder size, 6' x 12'
.._. _ - _--AverQge Curve
.00 .01 .0;_ .03 .04 .05 .06
STRAIH
Fig. A.70 . Stressvs. StrainResponseof A2%P0.75,1 Day,6"x 12" Cylinders
222
FRC - Tes_ Q_ I dayr_- Hybrid HIx
- 30/50 + 50/50 Hooked Fibers" VF = 1% ( oF Concrete)
i u_- CyUnder slze,6' x 12'v _ Average Curve
(/)_ _: -_,:__
Ld
- I I I I J.00 .01 .02 .03 .04 .05 ,06
STRAIN
Fig. A.71 - Stress vs. Strain Response of A1%$3S$, 1 Day, 6"x 12" Cylinders
o6
FRC - Tes_ a_ I dayI_- Hybrid Mix
- 30/50 + 50/50 Hooked Fibers
- VF = 2_ ( oF Concrete)
.._ u_ __"L ,, C_ltlnder size, 6" x 12"
_' Average Curve
V)bJIZt_ -, ,.,
-. t-•
I i I I I I I I I I I.00 .01 .02 .03 .04 .05 .06
STRAIH
Fig. A.72 - Stress vs. Strain Response of A2%S3S5,1 Day, 6"x 12" Cylinders
223
0oI
FRC - Test at I day
r_- Hybrid HIx
3/4' Potypropgtene +
- 30/50 Hooked F'lbers, VF = 1_.
.._ I_ Cy|lnder size, 6" x 12'
v _ __ Average Curve
_,_-
,00 ,01 ,02 .03 .04 ,05 .06
STRAIH
Fig. A.73 - Stress vs. Strain Response of AI%S3P0.75,1 Day, 6"x 12" Cylinders
0o
FRC - Test at I day
- Hybrid H1xm
3/4' Polypropgtene +
- 30/50 Hooked Fibers, V£ = 2_.
.._ _ Cytlnder size, 6' x 12'
- AverQge Curve_1: -
.00 .01 .0;_ .03 .04 .05 .06
8TRAIH
Fig. A.74 - Stress vs. StrainResponseof A2%S3P0.75,1 Day,6"x 12" Cylinders
224
00
reC - Test ot 1 d_j- Lo_ex Hlx
- 50/50 Hooked Steer Fibers
- VP = 17.
__ I_- Cy|lnder size, 6' x 12'v _ Averoge Curve
t tt •
t te t.
ai . ....
,00 ,01 .02 .03 .04 .05 .06
STRAIN
Fig. A.75 - Stress vs. Strain Response ofBl%S5,1 Day, 6"x 12" Cylinders
o
a}m
FRC - Test at I da_j- L_tex Mix
- Id2° Pol_jpropgtene Fibers
- VF = W.
_C ui - CyLinder size, 6 ° x 12"v _ _ Averoge Curve
•00 .01 .08 .03 ,04 .05 ,06
STRAIN
Fig.A.76- Stressvs.StrainResponseofB1%P0.S,IDay,6"x12"Cylinders
225
=Ln
FRC - Test _t 1 dayI_ SI[IcG Fume Mix
50/50 Hooked Fibers.
_o VF = t?.
mui (,',_, Cytlnder size, 6' x 12'
v '=_,/_. ___ Average Curve
I*t IlIit r . i
t • / t', "t _.
_ "l s_¢ L',•¢l"
I J I I I I I, I I I I,00 ,01 ,02 .03 .04 .05 ,06
STRAIN
Fig. A.77 - Stress vs. Strain Response of C I % $5,1 Day, 6"x 12" Cylinders
ooB
FRC - Test at I ,:Jayr< i- Sltlc= Fume Mix
- 3/4' Potypropytene Fibers- Vf = IX
p%
ui- C_jtlnder size, 6' x 12'v _ Average Curve
LJnte_
t
I I [ ..... I I .... 1.... _4 t I I I,00 ,Ot ,OP ,03 ,04 .05 ,06
STRAIN
Fig. A.78 - Stress vs. Strain Response of CI%P0.7S, 1 Day, 6"x 12" Cylinders
226
ao
F'RC - Tes't o,t I day
I'_- SILica Fune Hybrid Mtx- 30/50 + 50/50 Hooked F'tbers
- VF = W,
U'l Ir)- C_Llnder SlZe_ 6' x |E'
v - f_,, AverQge Curve
.00 .01 .08 .03 .04 .05 .06
STRAIH
Fig. A.79 - Stress vs. Strain Response of C1%$3S$, I Day, 6"x 12" Cylinders
227
05
FROl - Tesl ot 1,3,7.and 2B days
- HybridHlx- 2/'I'PotypropyLene+
_6- 30/50 Hooked Flber:s,V? = 1%
slze_ 4' x B'u5 Cylinder"
•,..,' F )_'_, ____ I doy
................3 d ys
oJFII_. \\ 'L"'..
I I " I I I 1 I I,00 ,01 ,02 03 ,04 ,05 ,06
STRAIN
Fig. A.80 - Stress vs. Strain Response of Mix AI %S3P0.5 with Time
05
FRC - Tes± a± 1 dog
- Hybrid Nix
- 2/4' Polypropylene+- 30/50 Hooked Fiber's,V? = 1Z
U% u_ - Cgtlnder slze, 4' x B' and 6' x 12'iv _ 4' x 8'
(,.,)_ _ - --- 6' x IP'0")w
I I I I..... I I I I I I I.00 .01 .02 .03 .04 .05 .06
STRAIN
Fig. A.81 - Effect of Cylinder Size on the Stress-Strain Response of Mix AI%S3P0.5
228
o5 | FRC - Test et 1,3,7, end 28 dQys
_- Hybrid HIx
. F Z/4' Potypropytene + ._0r- iN= 30/50 Hooked Fibers, VF = 2X.
.| lii -\ ,I d=u
.00 .01 .0P .03 .04 .05 .06
STRAIN
Fig. A.82. Stress vs. Strain Response of Mix A2%S3P0.5 with Time
o6
FRC - Test ot: 1 day
=- Hybrid HIx- 2/4' Potypropytene Fibers +- 30/50 Hooked Fibers, VF = 27.
_- Cylinder size, 4' x 8' and 6' x 12'Yv 4' x 8'
(/J _ 6' x 12'£/)bJ
n,'(_
(/) "k
°
' I _ _ I "1.... T--- I I I i I.00 .01 .02 .03 .04 .05 .06
STRAIN
Fig. A.83 - Effectof CylinderSizeontheStress-StrainResponseofMix A2%S3P0.5
229
.00 .01 ,02 .03 .04 .05 .06
STRAIH
Fig. A.84 - Stress vs. Strain Response of Mix B0%CON with Time
230
o';_| Test (_t 1,3,7, and ;)8 days
o_f L(lt;ex Mix
50,/50 Hooked Steer Fibers
r_ VF = 1_.
Cytlnder size, 4" x 8"
.I- -[- _ ..........3d°_,"E id-';'_.., ---_d°_s
.00 .OI .02 .03 .04 .05 .06
STRAIN
Fig. A.85 - Stressvs.Strain Responseof Mix B1%S5 with Time
FRC - Test at I dot.jr<- L(x_cex HIx
- 50/'50 Hooked $_ee| Fibers- VF = IZ
m.._ ui- Cytlnder size, 4' x 8' (xnd 6' x |2'v __ 4' x 8'
(/) q: 6' x 1@"(/3Ldn,'c, ii-
I I I I I I.00 .0! ,0;) .03 .04 .05 .06
STRAII'I
Fig. A.86 - Effect of Cylinder Size on the Stress-Strain Response of Mix B1%S5
231
o_
0o i F'RC - Tes¢ =t: 1o3,7., Qnd ;)8 days_ L_t.ex HIx
r_- 1/2' Po|ypropylene F'lbePs
__ _- Vf = IXA Cytinder size, 4 x8'|
F__-:/_"??, _-2. day,
.00 .01 .OP ,03 .04 .05 .06
STRAIM
Fig. A.87 - Stress vs. Strain Response of Mix BI%PO.5 with Time
_- FRC - Tes_ Q_ I doy- Lo_ex Mix
- 1/2' Po|ypr'opy|ene f'lber-s
v____ Cytlnder- size, 4' x 8" ¢md 6' x |;_'- _ 4' x 8"
E'_/V I "_'__! I I I I I I
,,,4
.00 .01 .OP .03 .04 .05 .06
STRAIM
Fig. A.88 - Effect of Cylinder Size on the Stress-Strain Response of Mix B1%P0.5
232
FRC - Test Qt 1.3.7, Gnd 28 dQysmSilica Fume HIx
IX. 50/50 Hooked Fibers
,-, VF = IX
.Xv v) Cylinder slze_ 4' x 8'
t
(/I I d_y
Ld _ - _"'-,.... .............3 daysf,y _ -
• "'""'" - - -7 d_ys• "'-.
C/) _ - "',, "............ • 28 days
• --...°._ °...
.00 .01 ,02 .03 .04 .05 .06
STRAIM
Fig. A.89 - Stress vs. Strain Response of Mix CI%SS with Time
I
FRC - Test at I day_:-SII.IcO. Fume HIx
50/50 Hooked Fibers
_6 - VF = W.._ p
.._ u') Cgllnder slzea 4" x 8' (lnd 6' x 12"v ' _ 4' x 8'
V) _: . - - -6" x 12'
(/) ''_'t.i.i
n,e_ ,-
I
!
' I I I I I I I I I I I.00 .01 .02 .03 .04 .05 .06
STRAIN
Fig. A.90 - Effect of Cylinder Size on the Stress.Strain Response of Mix C1%$5
233
o_
FR[" - Test at 1,3,7,_nd 28 dnys
oo- SILIcn FuMe HIx
I/2' PoLypropytene FibersIx.- VF = 1X
i Cylinder stze_4' x 8'---- I day
v uo 3 days
t. .... 7 daysb.I _rY _- , E8 days
_M
----.,.
I I I I I I I I i I I.00 .01 .02 .03 .04 .05 .06
STRAIM
Fig. A.91 - Stress vs. Strain Response of Mix CI%P0.5 with Time
o_D
FRC - Test =t 1 d=9D SILIc_ Fu_e HIx
- 3/4' Polypropylene Fibers- V_ = 1X
u_- CyLinder size, 4' x 8' _nd 6' x 12'Yv _ 4" x 8'
(/) _ D . -- -- --6" X 12'(/) 't
1
°
I I I I I I I I I I I,00 ,01 ,02 .03 ,04 .05 .06
STRAIH
Fig. A.92 - Effect of Cylinder Size on the Stress-Strain Response of Mix C1%P0.5
234
f FRC - Tes'¢ e_ L3,7, _nd 28 d_jsSitlce Fune H_jbrld HIx
} jt:, 4x._I" fA _"i:, __I d.,
"1:///t,",,, ---'"o_,
,:" "',. ,,..
,00 ,01 ,0_ ,03 .04 .05 .06
STRAIM
Fig. A.93 - Stress vs. Strain Response of Mix C1%$3S5 with Time
06w
FRC - Test ot I da MK
Silica FuMe Hgbrld HIx
30/50 + 50150 Hooked FlbePs
VF = 17.
u_ C_jllndeP slze_ 4' x 8" and 6" x IP"
_: - --6'x '
I I I I I I 1 1 I I !
.00 .01 .02 .03 .04 .05 .06
STRAIM
Fig. A.94 - Effect of Cylinder Size on the Stress-Strain Response of Mix C1%$3S5
235
oo
FRC - Test 61 ! d=yr< Conparo1:Ive Ev_tuQ1:lon
oi: DiFFerent: Mlxes_6- .."-'... V¢ = EX
j-%
"-'L/_In- / "... C.bj{Inder slze_ 4' x 8'- / : 30/50 Hooked St:eeL
(/_ _ _ i --_ 1/2' Potqpropqtene
ai
"'"'-......
i._ | |o' i , , , [.......... .....
STRAIN
Fig.A.95- EffectofFiberTypeontheIDay Stress-StrainResponse(Vf=2%)
o6
- "_:'%:. FRC - Test: Q1:28 d=qs
r_- f "".. Compara1:lve Evatua1:lon- i \ o¢ 111FFeren1: Mixes
',6- - '" VF = :_X . ,
v_u5- i :" Cqtlnder" size, 4 x 8
_._ i A '.. 30?0 Hooked St:eet
.00 .01 .OP .03 .04 .05 .06
STRAIH
Fig. A.96 - Effect of Fiber Type on the 28 Day Stress-Strain Response (Vf=2%)
236
°°LL FRC - Test at I d_H
r([ ComparQtlve Evatua¢lon
. F oF ])lFFerent Mixes
_ _t- H".._",,\ C_,.,,de,-s.ze.4'xF _'";i',\ --30/50 Hooke'`S_eet_-li -_;':_ ..............50/50Hook,'s̀_eeL
_' I-li ::;_. - - -30/50.50/50Hook..,Stee,.11:1_ '-% . 30/50Hookednher-s .
m r-I,L I '.._,I'-I_" _ ;'_' 1/2" Potyprop_jtene
• L,
t-/l \
,00 .01 .02 .03 ,04 .05 ,06
STRAIH
Fig. A.97 - Effect of Using2 Types of Fiber on the I Day Response(Vf=1%)
a_
FRC - Tes± Q¢ 1 d_yP_ Comparative Ev_tua_clon
. oF ])lFFeren¢ Hlxes
_o (/_ VF = 27,, \Ul
CytlndeP size, 4' x,,,uS 8'
v /', "_ __ 30/50 Hooked Steel(/) _ / _ \ ..............30/50 + 50/50 Hooked Steer
OO / ', _ - - -30/50 Hooked sleetbJ
/ .."_))_. _ + 1/2' Polypropytenenl _I-- ,:" _'-..
o.i
I I t t _ t I I l I ],00 .01 .02 ,03 ,04 .05 .06
STRAIH
Fig. A.98 - Effect of Using 2 Types of Fiber on the 1 Day Response (Vf=2%)
237
.
F'RC - Test _t ! da_j- ConparQtlve EvatuQtlon- 50/50 Hooked Steel F.Ibers
-F£. r
L# 1 _t_.::, ............ F'RC + LatexI_Wpi ..o,f_ [-_ 1 _, . Control + L,tex
.00 .0! .08 .03 .04 .05 .06
STRAIM
Fig. A.99 - Effect of Latex and Silica Fume on the 1 Day Stress-Strain Responseof the 50/50 Mix (Vf=l%)
F.RC - Test ot I dagr%Comparative EvaLuationPottjpropyiene F.Ibers
in._ IfJ CyLinder" slzel 4' x 8'V
-- PLain F'RC
GO - - -FRC + SIIIco FumeI.I _,'T'rY ei • -_ ................J:RC + L_tex
GO . _ : Control + L_tex
oJ
.00 .01 .02 .03 .04 .05 .06STRAIM
Fig. A.100 - Effect of Latex and Silica Fume on the 1 Day Stress-Strain Responseof the Polypropylene Mix (Vf=l%)
238
f FRC - Test at 1 deyComparative Evatu,,tlon (Hybrid HIx30/50 + 50/50 Hooked Steel
.l'- ",'X Sil=ar,,.e
.00 .01 .02 .03 .04 .05 .06
STRAIH
Fig.A.101 - Effectof SilicaFumeonthe1Day Stress-StrainResponseof the 30/50 + 50/50 Mix (Vf=1%)
- '°' F'RC - Test at P8 days
o0E /_\ Col_par_tlveEva[uatlon:_1 _ 50/50 Hooked Steel F'lber's
: ',.-...
'::LI i I k ""................. IrRC + Latex
03
.00 .01 .02 .03 .04 .05 ,06
STRAIH
Fig. A.]02 - Effect of Latex and Silica Fume on the 28 Day Stress-Strain Responseof the 50/50 Mix (Vf=1%)
239
(5
FRC - Test at 28 days
r_ - Conp_r_tlvervQtua,t10nPoigpropyieneFibers
; VF = W.;t .
°_ ; --
I_ Cgtlnder slze_ 4' x 8"Plain FRC
:',iC,_ - - -F'RC + SI[Ic(I F'ul,le
: t
I-'- _ _ ...............JrRC �L_'texC,q - .:.._ ,, Con'trot + L_tex
03- ,.
i i I i I I i i i t i.00 .01 .0P .03 .04 .05 .06
STRAIH
Fig.A.103 - Effect of Latex and Silica Fume on the 28 Day Strew-Strain Responseof the Polypropylene Mix ('Vf=1%)
.00 .01 .0_ .03 ,04 .05 .06
STRAIH
Fig. A.104 - Effect or Silica Fume on the 28 Day Stress-Strain Responseof the 30/50 + 50/50 Mix 0/r=1%)
240
8A
¢¢¢¢
in
(n 5 ---"_-
d 4
3Type of Fibers: 30/50 Hooked Steel
2 -- _-- Controlo Vf = 1%
1 - Vf = 2%
! ! ! I
1 3 7 28
Time, days
Fig. A.105 - Compressive Strength, f'c vs. Time, 30/50 Steel Fibers
8
=,=,_ ,== ,_, ==, 4_ _ _ _ _ _ _ m m _1_
6
•_ 5 ....
"" 3 Type of Fibers:3/4" Polypropylene Fibers
2 --_-- Controlo , Vf= 1%
1 - Vf = 2%
I I I l
1 3 7 28
Time, days
Fig. A.106 - Compressive Strength, f'c vs. Time, 3/4" Polypropylene Fibers
241
8
7
6
mDw_
UD --
Type of Fibers:2 30/50 + 50/50 Hooked Steel
---'*'-" Control1 . o Vf=1%
= Vf = 2%I ! ! !
1 3 7 28
Time, days
Fig. A.107 - Compressive Strength, f'c vs. Time, 30/50 - 50/50 Steel Fibers
8
J
4
Type of Fibers:;-" 3 30/50 Hooked Steel +
2 3/4" Polypropylene Fibers---x-- D Control
1 0 Vf = 1%= Vf = 2%
O I I I I
1 3 7 28
Tlme, days
Fig. A.108 - Compressive Strength, f'c vs. Time, 30/50 Steel + 3/4" Polypropylene Fibers
242
9
7 .,.,.....,....'tP
6
Chemical Additive: Latex
"- 3 Vf = 1%
2 -- _-- Controlo 50/50
1 -- Polypropylene* Control + Latex
I I I I
1 3 7 28
Time, days
Fig. A.109 - Compressive Strength, f'c vs. Time, Latex, (Vf=1%)
9
8
7 41" ----41_
.___.,_64'*"fJ _ Chemical Additive: Silica Fume
3 Vf = 1%
-- _-- Control2 _ 50/50
1 -----a---- Polypropylene-'- 30/50 + 50/50
! I I ] l
1 3 7 28Time, days
Fig. A.110 - Compressive Strength, f'c vs. Time, Silica Fume, (Vf=l%)
243
7
• `* _' _lf" _ _w
6im
u)._¢ 5 ....
¢; 4'_. Type of Fibers:
30/50 + 50/50 Hooked Steel3Vf = 1%
2 --_-" Controlo , Plain FRC
1 -- ' Silica Fume Modified FRC
I I I I
1 3 7 28
Time, days
Fig. A.111 - Compressive Strength, fc vs. Time, 30/50 + 50/50 Steel Fibers, (Vf=l%)
244
7000
ooo5000
•-_ 4000
GuJ 3000 Type of Fibers:
30/50 Hooked Steel
2000 --_-- ControlVf= 1%
1000 ¢ Vf = 2%
I I l I
1 3 7 28
Time, days
Fig. A.112 - Elastic Modulus, Ec vs.Time, 30/50 Steel Fibers
5O0O
4500
4000 ........
3500
"- __' 3000 _- ____
m n=
o" 2500IJJ
2000 Type of Fibers:3/4" Polypropylene Fibers
1500-- "_-- Control
1000 --,-o--. Vf = 1%Vf = 2%
5OO
i | ! !
1 3 7 28
Time, days
Fig. A.113 - Elastic Modulus, Ee vs.Time, 3/4" Polypropylene Fibers
245
5OOO
45OO
4000 x- u-......... . - _
•_ 3000
G 25oo/ Type of Fibers:
uJ 2000 / 30/50 Hooked Steel +1500 i" 3/4" Polypropylene Fibers
1000 -- _-- ControlVf= 1%
500 = Vf = 2%
0 , , , , I1 3 7 28
Time, clays
Fig. A.114 - Elastic Modulus, Ec vs. Time, 30/50 Steel + 3/4" Polypropylene Fibers
5O0O
4500
4000 x-........ u- ........ _- ...... _O
-3000
tS 2500ill
2000 Type of Fibers::30150 + 50150 Hooked Steel
1500--"_--- Control
1000 Vf = 1%-- Vf = 2%5OO
I I I I
1 3 7 28
Time, days
Fig. A.II5 - Elastic Modulus, Ec vs.Time, 30/50 + 50/50 Steel Fibers
246
I
8OOO
7000 Chemical Additive: Latex
6000 Vf = 1%
50OOmm
U'}
r_ 4000 x- 41(IJ,I
3000
2000 --"_'-- Control (Plain Concrete)50/50
1000 ; Polypropylene•J- Control + Latex
I I i l
1 3 7 28
Time, clays
Fig. A.II6 - Elastic Modulus, Ec vs. Time, Latex, (Vf=1%)
5OOO
4500
4000 --'_" ....
35OOm
,.¢ 3000
G 2500IJJ
2000Chemical Additive: Silica Fume
1500 Vf = 1% __.._._. Control1000 o 50/50
-- Polypropylene500 A 30/50 + 50/50
I I I I
1 3 7 28
Time, days
Fig. A.II7-ElasticModulus, Ec vs. Time, Silica Fume,(Vf=l%)
247
8000 1 --"_'-" Control /m7000 --o--- Plain FRC /
6000 1 Latex Modified FRC /
_ 5000t• A S lica Fume Modified FRO /
t ,1002 ] =
1 3 7 28
Time, days
Fig. A.118 - Elastic Modulus, Ec vs.Time, 50/50 Steel Fibers, (Vf=l%)
7000
Type of Fibers: Polypr0pylene6000 Vf = 1%
5000=me=
x- _- ........ _._4000 - - - ._
¢;uJ 3000
2000 ---=--- ControlPlain FRC
1000 " Latex Modified FRC-'- Silica Fume ModifiedFRC
01 3 7 28
Time, days
Fig. A.II9 - Elastic Modulus, Ec vs. Time, Polypropylene Fibers, (Vf=1%)
248
5000
4500
35004000 _ ........•_ 3000
2500o" Type of Fibers:u,I 2000 30/50 + 50/50 Hooked Steel
1500 Vf = 1%
1000 ---m--- ControlPlain FRC
500 -- Silica Fume ModifiedFRC
01 3 7 28
Time, days
Fig. A.120 - Elastic Modulus, Ec vs. Time, 30/50 + 50/50 Steel Fibers, (Vf=1%)
249
Appendix B
Bending and Tensile Tests
Table B.1 : Strength Results for each Individual Specimen.
Fig. B.1 - B.16: Graphs of Load versus Deflection and Strain Capacity Response
with Time.
Fig. B.17 - B.20: Load versus Deflection Response for Different Series.
Fig. B.21 - B.29: Modulus of Rupture fr.
Fig. B.30 - B.39: Toughness Indices.
251
Table B.1. Detailed fc, fr, and fspt Data
Mix ID Specimen fr fc ,_sptID (psi) (ksi) (_si)
Control t 1D_I 637.5 4.22 517.25Control 1i3_2 .... 656.25 --- 298.42 ....Control "iD AV '_ 646.88 ..... 4.22 - 407.83 'Control 1D_I 600.0 ......_ontr0i _D_2 ...... --- _--
_.ontrol 7D AV 600.0 "--- ......... ---_ontrol 28D_1 712.5 ......Cgntrol ..28D 2 ......... 868.13 ......Control 28D AV 790.31 --- ".... ---A1%S3 1DT 1162.5 ' 3.26 696.3A1%S3 19_2 712.5 --- 795.77)_i %S3 ID AV 937.5 3.26 746.04A1%S3 7D_l 900.0 ......A1%S3 'lD_2 910.5 ...... -.....Ai%S3 7D AV ..... 905.25 ...... --....A1%S3 28D_1 1068.75 ......Ai%S3 " ' 28D_2 806.25 ...... "A1%S3 28D AV 937.5 ......A2%S3 1D_I 1612.5 5.73 1014.61A2%S3 1D_2 1477.5 5.93 1034.51A2 %S3 iD AV 1545.0 5.83 _' 1024.56A2%S3 7D_-1 1882.5 ......_2%S3 7D_2 i850.63 ...... ' '-A2%S3 7D AV ....1866.56 --- ' ---
IA2%S3 281__1 1567.5 ......
A2%s3 2fl13_2 2068.13 ...... .......A2%S3 28D.AV _ 1817.81 ...... ....
continued on next page
252
Table B.1. Detailed fc, fr, and fspt Data; continued
Mix ID Specimen fr fc fsptID (psi) (ksi) (psi)
A1%S5 1D_I 1271.25 4.42 925.09A1%S5 1D_2 = i63i125 ......... 5_16........... 835.56 .....A1%S5 .... iD AV 145L25 4.79 880.33A1%S5 7D-_l 1575.0 ......A1%S5 7D_2 ........._.1%S5 71) AV 1575.0 ......A1%S5 281__1 1875.0 ......A1%S5 28D_2 ..... i4'62.0 --- ' ---A1 _S5 .... 28D AV 1668.75 ......
A0.15%P0.5 1D=I 564.38 ............ 3:63 ........ 448.02 ....A0.15%P0.5 1D_2 510.0 4.7 472.69_,0,15%P0,5 iD'AV 537.19 4.16 ...... 460.36
A0.15%P0.5 7D1 750.0 ..... -.....K0:i5%P0.5 7D_2 825.0 ......A0.i5%P0.5 7D AV 787.5 ......A0.15%P0.5 28D_1 840 ......A0.15%P0.5 28D_2 ...... 846 ......_0.iS-%P0:5 -- -_28D-AV .......................... 843- --- ---Al%P0.5 1D__ 609.38 3.7 596.83._].%'P0.5 1D 2 ...........678.75 4.46 ........ 660.49_i %'P0.5 ID-AV 644:06 .... 4.08 " 628.66Al%P0.5 _D_1 669.38 ......_1%P0.5 "7D_2 • " 733. i3 --- ...... ---Al%'P0.5 -- 7D AV '70i:25 ......... _ ------ - --:: .....Al%P0.5 28D_1 928.13 ......Al%P0.5 28D_2 948.75 ......_1%P0.5 28D AV 938.44 ......A2%P0.5 1D_I 461.25 2.52 527.2A2%P0.5 1D_2 457.5 ......A2%P0.5 iD AV 459.38 2.52 527.2A2%P0.5 YD_I 658.13 ......A2vo.5 702 581:25 ""iii i-- =:-................A2%P0.5 YD AV ' 619.69 ......A2%P0.5 28D_1 646.88 ......A2%P0.5 2813'_2........ 618.75 _ -_- : --- .............A2%P0.5 28DAV .................. 632.81 ......
continued on next page
253
Table B.1. Detailed fc, fr, and fspt Data; continued
Mix ID Specimen fr fc _sptID (psi) (ksi) ()si)
A1%S3S5 1D1 1093.13 4.06 716.2A1%S3S5 1D_2 905.63 5.09 580.92 ........Ai %S3S5 ID AV 999.38 4.58 648.56A1%S3S5 7D-1 1518.75 ......A1%S3S5 _D_2 1303.13 ...... -...........A1%S3S5...........7D AV 1410.94 ......Al%S3S5 28D_1 1275.0 ......A1%S__3__S_5.... 2802 1368.75 ......A1%S3S5 Z8D AV 1321.88 ......
A2%S3S5.......... 1D_I .... 1430.63 , , 5.05 ...... ....... 1124.03A2%S3S5 1D_2 1605.0 5.41 966.87A2 %S3S5 ID AV 15i7.81 5.23 1045.45A2%S3S5 rD'l 1800.0 ......A2%S3S5 L7D--2 ' ' 1715.63 ......A2%S3S5 7D AV 1757.81 ......A2%S3S5 28I__1 2118.75 ......A2%S3S5 28D_2 1706.25 ......A2%S3S5 28D AV 1912.5 ...... ...........Al%S3P0.5 1D ]" 600.0 4.46 574.95Ai%S3P0.5 1D_2 695.63 3.98 557.04Ai %S3P0.5 1D AV 647.81 4,22 565.99Al%S3P0.5 7D_1 791.25 ......AI%S3P0.5 70_2 750.0 ......Ai%S3P0.5 7D AV ..... 770.63 ......Al%S3P0.5 28D_1 975.0 ......Al%S3P0.5 28D_2' ' 843.75" ' -.....Ai%S3P0.5 28D AV 909.38 ......A2%S3P0.5 1D_I 562.5 3.58 628.66A2%S3P0.5 1D_2 866.25 3.98 527.2A2%S3P0.5 ID AV 714.38 3.78 577.93A2%S3P0.5 7D_1 838.13 ......A2%S3P05 7D_2 1031.25 ......A2%S3P0.5 7D AV 934.69 -.....A2%S3P0.5 28D_1 1078.13 ......A2% $3P0.5 :28D_2 ......... 1031.25 ......A2%S3P0.5 28D AV 1054.69 --- ........ --- ..............
continued on next page
254
Table B.1. Detailed fc, fr, and fspt Data; continued
Mix ID Specimen fr fc fsptID (psi) (ksi) (psi)
B 1%S5 1D_I 1021.88 3.26 .... 636.62 _B1%S5 1D_2 993.75 2.71 696.3B1-%S5 1D AV ' 1007.81 2.98 666:46B1%85 D_I 1350.0 ......i_1%S5 7D_2 1406.25 ......B1%S5 TD A 1378.13 ......31%S5 28D_lV 1987.5 --- . :--81%S5 28D_2 1856.25 ......B1%S5 28D AV 1921.88 ......B1%P0.5 1D_I 551.25 2.63 318.3181%P0.5 ..... 1D_2 600.0 2.47 .... 33812 .......Bi%P0.5 1D AV 575.63 2.55 328.26B1%P0.5 7D_-1 562.5 ......[31%P0.5 7D.__.2 712.5 --- ---Bl%P0.5 7D AV 637.5 ......B1%P0.5 281_ 1 843.75 ......
"r',
B1%P0.5 28D_2 900.0 ......BI%P0.5 ZSD AV 871.88 ......81%S3S5 1D_T 1068.75 3.5 457.57B1%S3S5 1D_2 958.13 3.66 557.04B1%S3S5 1D AV 1013.44 3.58 507.31B1%S3S5 'D-1 1462.5 ......Bi%S3S5 rD_2 1350.0 --- ........ ---B1%S3S5 7D AV 1406.25 ......
B1%S3S5 28D1 1631.25 -..... •B1%S3S5 28D_2 1875.0 ......
B|%S3S5 Z8D.AV 1753.i3 ......
continued on next page
255
Table B.1. Detailed fc, fr, and fspt Data; continued
Mix ID Specimen fr fc fsptID (psi) (ksi) (psi)
C1%$5 1D_I 1106.25 4.93 827.61C 1%S5 1D_2 1350.0 5.36 89 i.27C1%S5 1D AV 1228.13 5.15 859.44C1%$5 7D 1 1455.0 ......C1%$5 7D_2 i443.75 ......C1%$5 7D AV 1449238 ......C1%$5 28D_1 1706.25 ......C1%$5 28D_2 2250.0 ......C1%S5 28D AV .........i978.13 .... --- ---
C1%P0.5 1D.__ 525.0 3.66 437.68C1%P0.5 1D_2 581.25 3.74 447.62C1%P0.5 iD AV 553.13 3.7 442.65Cl%P0.5 7D_l 641.25 ......01%P0.5 rD_2 656.25 ......C1%P0.5 7D AV .... 648.75 ......21%P0.5 Z8_l 843.75 ......Cl%P0.5 28D_2 731.25 ......C1-%P0.5- 28D AV .......... 787.5 ...... -"-- ---
1
C1%S3S5 1D...1 993.75 4.6 839.54........................ ,
C1%$3S5 1D_2 975_0 i.85 765.93C1% $3S5 1D AV 984.38 4.72 802.74C1%$3S5 7D_l 1537.5 ......Ci%$3S5 7D 2 1312.5 ......ci%$3S5 7'i_'=-AV 1425.0 ......C1%$3S5 28D_1 1481.25 ......C1%$3S5 28D_2 12i8.75 .............................
C1%$3S5 28D AV 1350.0 ......
256
m
m FRC - Fiexurat Test at I,7, and 28 days- Hgbrld Hlx
o_- 30/50 + 50/50 Hooked Steel Fibers
- /.,, V? = IX
. / %t,qI
_ bl/"',, '_,, - - -7 daus
.00 .10 20 .30 .40 .50 .60
DEFLECTION (in)
Fig. B.1 - Effect of Time on Load vs. Deflection Response, 30/50 + 50/50 Steel Fibers,(Vf=l%)
/o_F FRC - flexurat Test at L 7, and _8 days
/
!" Hybr'ld HIx
ooI- 30/50 �50/50Hooked Steer Fiber's!" ,''- VF = IX
_I-,"A_
...'% .... "'.°.......%
,oo .o3 ,os .o9 ._e ._5STRAIM CAPACITY (an/In)
Fig. B.2 - Effect of Time on Load vs. Strain Capacity Response, 30/50 + 50/50 SteelFibers, (Vf=l%)
257
dI
FRC - Ftexur,atTest ot 1,7, and 28 daysHybr,_dHix30/50 Hooked Steel + I/2'
Potypr,opytene Fibers
_0. _ VF = 1'?.
u_ ...............I day
- - - 7 dags
_ _ 28 daysr6
o_
.00 .10 .PO .30 .40 .50 .60
DEFLECTION (an)
Fig. B.3. Effect of Time on Load vs. Deflection Response, 30150 Steel +1/2" Polypropylene Fibers, (V£=1%)
dm
o,;- FRC - Ftexurat Test at 7 and P8 days- Ht,jbr'ld Mix
o6- 30/50 Hooked Steel �I/2'
- Potypr'opt,jtene FIber,sr_-. VF = 17.
-
__-i
V
u_-
. - - - - 7 days
<£ ,=. _1 __
-'J r6-_I
II
I
7 ---: ..........I
_" I I I I I I I i 1 ,.00 .03 .06 .09 32 .15
STRAIH CAPACITY (an/an)
Fig. B.4 - Effect of Time on Load vs. Strain Capacity Response, 30/50 Steel +1/2" Polypropylene Fibers, (Vf=1%)
258
o
o_- FRC - Ftexurot Test at I,7, and 28 days
_ Hybrld Hlx
0_- 30/50 Hooked Steer + I/2'
- Polypropytene Fibers
_0 r_- VF = 2X
v_ 'SF_.._ ...............1 dau
_[-/,;'_,_.,-- - --7 daus
ai
.00 .10 .20 .30 .40 .50 .60
DEFLECTInH (in)
Fig. B.5 - Effect of Time on Load vs. Deflection Response,30/50 Steel +1/2" PolypropyleneFibers, (V£=2%)
o_- FRC - Ftexurat Test at I,7, and 28 days
- H_Jbrld HIx I
a:i- 30/50 Hooked Steer + 1/2' I
- Potypropytene Fibers I
v,- I_.._ ...............1_,o,, I
,-, -',_._ - - - 7 days I_: L --28 days
I I I I I i i.00 .03 .06 .09 A2 .15
STRAIM CAPACITY (in/in)
Fig. B.6 - Effect of Time on Load vs. Strain Capacity Response, 30/50 Steel +1/2" Polypropylene Fibers, (Vf=2%)
259
FRC - Ftexurat Tes_ cL_ L 7. and e8 dayse,,,e
Latex Mix
50/50 _ooked S_eeL Fibers
VF = I_
Lf) _lCL r_ ...............! dayy , - - - 7 day
_ ', 28 day.-" "'... •
"". •
[] _r :
: ""'.....
...... ..................: "... ..(_J : "..
.00 .10 .20 .30 ,40 .50 .60
DEFLECTIDM (in)
Fig. B.7 - Effect of Time on Load vs. Deflection Response, 50/50 Steel Fibers,(Vf=l%)
,,...4
FRC - Ftexurat Test al: 1, 7, and ;)8 daysLa'l:ex Hix
o_ 50/50 Hooked Steer Fibers
a_ V£ = 1_.
C]. r_ ""................ 1 dQ_jy
v _ -,,, - - -7 d"_J"- _ ;)8 datj (Shear Failure)
[d . ......
°..... 'b_
I I I I I I.00 .03 .06 .09 .IP ,15
STRAIH CAPACITY (in/in)
Fig. B.8 - Effect of Time on Load vs. Strain Capacity Response, 50/50 Steel Fibers,(Vf=l%)
260
o_
: ___C___I:x-°__'"°___°°"_""°_- 1/2" PotypropyLene Fibers- V# = 17.
uS_- - - -7 day
.00 .10 .20 .30 .40 .50 .60
DEFLECTIOH (in)
Fig. B.9 - Effect of Time on Load vs. Deflection Response, Latex,1/2" Polypropylene Fibers, (Vf=] %)
c5i
o_- FRC - Flexurat Test st 1, 7, and P8 d_ys- Latex Hix
oo- 1/2' Poiypropyiene Fibers- V,F = 17.
-
__-................ I d_y
.... 7 dayI
I_ _ 28 d_y
r7
d_ir-°°_
ai
. - -?--"---..'..--'---.---.-..':=r.::__ °......
i I i I I I ....i ...........I........-7-"----,00 .03 .06 .09 .1P .15
STRAIH CAPACITY (in/in)
Fig. B.10 - Effect of Time on Load vs. Strain Capacity Response, Latex,1/2" Polypropylene Fibers, (Vf=1%)
261
°
/'_ FRC - I:'|exurot Tes'l; a't I, P, end :_8 doqsIt
/\ sit,co ru.e MixO_ /\ 50/50 Hooked Steel F'd0ers
* t . . / VF : IL_i "I ., t
:/ ..............I doy
.+ :: ':_\ .__de do,y
_: ,: . •....r: • "'-
e+ -'L...........+d
I t | I I I I I I I I.00 .10 .20 .30 .40 .50 .60
DEFLECTION (in)Fig. B.11 - Effect of Time on Load vs. Deflection Response, Silica Fume,
50/50 Steel Fibers, (Vf=l%)c_
_"/__, FRC - FLexuraL Test at I,7, and 28 days
SILICa Fume Mix
50/50 Hooked Steel Fibers
-'" VF = I?.r,,[
I day%%%%I...-.
j o • * °.. • .euoeoeemmHse
,_j_ _,.o ... -_............ _',,", - - - 7 day
,_ _... __ 2ed_A ..... ;:.- .,:..,<E _ ...,,,.r,_ ,_.,.°
-
I I I I I I I I.00 .03 .06 .09 .1;) .15
STRAIH CAPACITY (in/in)
Fig. B.I2 - Effect of Time on Load vs. Strain Capacity Response, Silica Fume,50/50 Steel Fibers, (Vf=l%)
262
B
oq- FRC - Ftexurat Test at L 7, and 28 days- SltlcaFume Hlx
od- 1/2' Potgpropytene Fibers
rC i V_=l%
v ................ I dag
.... 7 dag
_:- _ P8 day
r_;#[ l'<k i""__ J J l J l l l.00 .10 .20 .30 ,40 .50 .60
DEFLECTION (in)Fig.B.13 - Effectof Time on Load vs.DeflectionResponse,SilicaFume,
1/2" Polypropylene Fibers, (Vf=1%)
oq 7, Qnd 28 days
_- SILica Fume HIx _
o_ I/2'Potypropglene Fibers
r_ VF= IY.
...............1 day
_- - - -7 dQy
-J _
.00 .03 .06 .09 .IP .15
STRAIN CAPACITY (in/in)
Fig. B.14 - Effect of Time on Load vs. Strain Capacity Response, Silica Fume,1/2" Polypropylene Fibers, (Vf=1%)
263
/
o_F FRC - Ftexurat Test a'l: 1. 7. and 88 daysh Silica Fur,re Mix
aJ [- 30/50 + 50/50 Hooked S't:eel, FibersI- vf = t_:
r<l-
_--_v_ "__'",, ................1 day
U'J[-[.."'".._',, - - - 7 datJ
(_ .... .".:.v......;* • .. .....
I I I I I.00 .10 .20 .30 .40 .50 .60
DEFLECTIDM (in;,
Fig. B.lS - Effect of Time on Load vs. Deflection Response, Silica Fume,30/50 + 50/50 Steel Fibers, (Vf=l%)
d
"Lm
oq- FRC - Flexurat Tes_ at 1, 7, and 28 dagsSltlca Fune HIx
o_ 30/50 + 50/50 Hooked S_eet Fibers
. VF = IZ
_c3.,_ ,,,. ...............z dayv"Y , ...... _._", - - - 7 day
""'........... " , _ P8 day:.-" "°'_'"...o..o.. _
,q_ _: '... -,[_ _ '""°'°"-.%° _
...1 e.i
ai ! _.m
_ -
I I I I I I I I I.00 ,03 ,06 .09 .1P .15
STRAIN CAPACITY (In/In)
Fig. B.16 - Effect of Time on Load vs. Strain Capacity Response, Silica Fume,30/50 + 50/50 Steel Fibers, (Vf=l%)
264
°O
FRC - Ftexurot Test at 1 dogConporotlve Evo[uatlon
06 1/2' Potgpropgtene FibersV¢ = I%
L_
_Y Hol.dslzeJ4' x 4' x 16"%=S
u_ -- Con'trot
...............PtalnFRC,_ _ - - - SI|Ico FuMe[] = Latex
.,,.
,,
"'.....
"'."... ,.
.00 .10 .20 .30 .40 .50 .60
DEFLECTIDH (in)Fig. B.17 - Effect of Additive on Load vs. Deflection Response, 1 Day,
1/2" Polypropylene Fibers, (Wf:l%).
FRC - Ftexurot Test ot 28 dogs
Comporol;IveEvotuo1:mon
o_ I/2' Potgpropgtene FibersV? = I%
v___ Motd slze,4" x 4' x 16'-- ControI...............PtalnFRC
_ - - - SlIlCoFume
I_1 : Latexr_
oJ
..4
I 1 i I I I I.00 .10 20 .30 .40 .50 .60
I)EFLECTIFIH (in)Fig. B.18 - Effect of Additive on Load vs. Strain Capacity Response, 1 Day,
1/2" Polypropylene Fibers, (Vf=l%)
265
C_
I
o_- Hybrid FRC - Fiexural Test at 1 dog- Comparative Evatu(xtlon- 30/'50 + 50/50 Hooked Steel Fibers
- V? = 1Z_-_ I_ -L_ --
._0-_i -I Hold size, 4' x 4" x 16'
" • . Control
l-I"_', ...............Plo,_F_C
o ri _..".. . Latex_! c6 ....%,
I I I I I I I I I I I
.00 .I0 .ao .30 .40 ,50 .co
DEFLECTIDH (in)Fig. B.19 - Effect of Additive on Load vs. Deflection Response, 1 Day,
30/50 + 50/50 Steel Fibers, (Vf=l%)°
o_ Hybrid FRC - FlexuraL Test _t P8 daysComparative Evatuatlc, n
o_ 30/50 + 50/50 Hooked Steel Fibers
VF = IZ
t ",
: t ",EL_ : ,__ , :- Hold size, 4" x 4' x 16'
' _ Con_r'oI[_ | -I
' "................ Plain FRC
<:_ _: , ... - - - Sltlco, Fume[] "" "".. ,_. L_'t.e,K_1 oi -.. "'.
°v-4
I I I I I I I I I,00 .10 .eO .30 .40 .50 .60
]3EFLECTIFIH (in)Fig. B.20 - Effect of Additive on Load vs. Strain Capacity Response, l Day,
30/50 + S0/S0Steel Fibers, (Vf=l%)
266
2OOO
1800 _ "1600
1400
1200,m
o..1000
o-- c_ Jo',- 800 ..-K
----"--- Control400 o Vf=1%
200 -- Vf=2%
i I !
1 7 28
Time, days
Fig. B.21 - Modulus of Rupture fr vs. Time, 30/50 Steel Fibers
1000
800
600D..
400--'_-- Control
A Vf = 0.15%200 O Vf=1%
-- Vf=2%
I I I
1 7 28
Time, days
Fig. B.22 - Modulus of Rupture fr vs. Time, 1/2" Polypropylene Fibers
267
2000
lsoo1600
14oo•_ 1200
1000
800 .-x
600 _ "_---'_--- Control
400 -o Vf=1%-- Vf=2%200
0 I I I
1 7 28
Time, days
Fig. B.23 - Modulus of Rupture fr vs. Time, 30/50 + 50/50 Steel Fibers
1200
1000
.- 800 r_'___
600 .........."=.-
400 ----_--- Controlo Vf=1%; Vf=2%
200
I I I
1 7 28
Time, days
Fig. B.24 - Modulus of Rupture fr vs. Time, 30/50 Steel + 1/2" Polypropylene Fibers
268
2000 .... _--- Control18oo o 50/20
a Polypropylene fibers /_1600 -"- 30/50 + 50/50 _1400
•_ 1200
1000
_" 800 ..-K
600
400
2OO
I 1 I
1 7 28
Time, days
Fig. B.25 - Modulus of Rupture fr vs. Time, Latex, (Vf=1%)
2O00
1800
1600
1400
"_ 1200
1000i,,."
8006OO---"_--- Control
400 o 50/50
200 [] Polypropylene fibers-'- 30/50 + 50/50
I 1 I
1 7 28
Time, days
Fig. B.26 - Modulus of Rupture fr vs. Time, Silica Fume, (Vf=1%)
269
2oooi1800-
1600"
1400
'_ 1200D,,
1000
"- 800 .........=
600 m.................. -w........... -_--- Control
400 -----o Plain FRC
200 m'o Latex Modified FRC-_ Silica Fume Modified
I I !
1 7 28
Time, days
Fig. B.27 - Effect of Additive on the Modulus of Rupture fr vs.Time,50/50 Steel Fibers, (Vf=I%)
1000
800 _
•_ 600 _'"D,.
" 400
---"w--- Controlo---- Plain FRC
200 [] Latex Modified FRC
•_ Silica Fume Modified
1 I I
1 7 28
Time, days
Fig. B.28 - Effect of Additive on the Modulus of Rupture fr vs. Time,
Polypropylene, (Vf=1%)
270
1800
1600
1400
120OiE
_. 1000
800 K
600' H. .-w
' ---"_--- Control4O0 - , o Plain FRC
n Latex Modified FRC200
A Silica Fume Modified -
I I !
1 7 28
Time, days
Fig. B.29 - Effect of Additive on the Modulus of Rupture fr vs. Time,30/50 + 50/50 Steel Fibers, (Vf=1%)
271
20 Type of Fibers:1/2" Polypropylene
Vf = 2%
....... q -.--o-- 15-1stCR_ ----o 15-CO
"1oc _ .... 4-- IIO-lstCR-- _' _" = I10-C0t_ 10t/J O- ... _
C b " -. O, ,_
oI-
0 i ! i
1 7 28
Time, days
Fig. B.30 - Toughness Index Is and I1ovs. Time, 1/2" Polypropylene Fibers, (Vf=2%)
30 "_ Type of Fibers:30/50 Hooked Steel +50/50 Hooked Steel
---o-- Vf = 1%
= 15-CO _--x"¢_ 20 --4-- IlO-lstCR ---"""""_'10_- : 110-CO
m
o" 10
O ..... O- O
1 i i
1 7 28
Time, days
Fig. B.31 - Toughness Index Is and I1ovs. Time, 30/50 + 50/50 Steel Fibers, (Vf=1%)
272
70 Type of Fibers:30/50 Hooked Steel +
60 _ 50150 Hooked SteelVf = 2%
. 50' _ --.o-- 15-1stCR
x _ o_ 15-CO
•o _ --4-- I10-1stCRc: 40 ---t--- I10-CO
= \
= 2OO
10 ........
0 ___1 7 28
Time, days
Fig. B.32 - Toughness Index Is and Ilo vs. Time, 30/50 + 50/50 Steel Fibers, (Vf=2%)
30- Type of Fibers:112" Polypropylene +
30/50 Hooked Steel
25 Vf = 1%
,. -- ,o-- 15-1stCRi&
20 .% - _- 15-CO%
.% --,,,-- I10-1stCR"o \
.%
_= .---.---i10-co15 .% _ ..."
l- 10 o. x
_- 5'
0 281 7
Time, days
Fig. B.33 - Toughness Index Isand Ilo vs. Time, 30/50 Steel + 1/2" PolypropyleneFiber, (Vf=1%)
273
10
--w_" Type of Fibers:--... 1/2" Polypropylene
"-.. Vf = 1%8 _ " ",t Chemical Additive:
"x _ _\ Silica Fume
C \
t-
---o-- 15-1stCR0
o 15-C0 ,, _4-- IlO-lstCR "_o-- I10-C0
I I I
1 7 28
Time, days
Fig. B.34. Toughness Index Is and I10 vs. Time, 1/2" Polypropylene Fibers,
Silica Fume, (Vf=l%)
40Type of Fibers:
30150 Hooked Steel +50150 Hooked Steel
Vf = 1%30' _ Chemical Additive:I,,,,,,,I
Silica Fumex"oJ "_. - - ,o -- - 15-1stCR
_= °- is-co--t--- IlO-lstCR2O
"%.
m - _=..-= _- -- I10-C0
_ r ''_
OI-- o- ...............
0 | i i
1 7 28
Time, days
Fig. B.35 - Toughness Index Is and Ilo vs. Time, 30/50 + 50/50 Steel Fibers,
Silica Fume, (Vf=1%)
274
120
o 30/50
1O0 % a Polypropylene Fibers
o 80 _ :- 30/50 + 50/50O
c_ 6O
Ill
4O-II
2O[1,,
I ! I
1 7 28
Time, days
Fig. B.36 - Toughness Index 12o -co vs. Time for Different Mixes, (Vf=2%)
60
50
.. 40o
"" 30
20
o
,o • _o,so+so,so \: Polypropylene +30150 __
I I I
1 7 28
Time, clays
Fig. B.37 - Toughness Index Izo-lst-CRvs. Time for Different Mixes, (Vf=2%)
275
5O
40
o3O
0
o•.o Polypropylene Fibers
., 20 -- 30/50 + 50/50
10 c_"'U
I I 1
1 7 28
Time, daysFig. B.38 - Toughness Index I2o-co vs. Time for Different Mixes, Latex, (Vf=1%)
IO0
" 50/50" Polypropylene Fibers
80 _-- 30/50 + 50/500o 6O
O4
,-- 40
20
0 , ! !
1 7 28
Time, days
Fig. B.39- ToughnessIndex I20 -co vs. Timefor DifferentMixes,SilicaFume, (Vf=l%)
276
Appendix C
Fatigue Tests
Fig. C.1 - C.7 : Load versus Deflection Hysteretic Response under
Fatigue Loading
Fig. C.8 - C12 : Variation of Deflection versus Number of Cycles
Fig. C.13 : Load versus Deflection Response after Fatigue Loading
Fig. C.14 - C18: Variation of Strain versus Number of Cycles
Fig. C.19 - C20: Load versus Strain Response after Fatigue Loading
Fig. C.21 - C30: Load versus Strain Response under Static Loading
Fig. C.31 - C38: Load versus Strain Response under Static Loading
277
8.00 .... f .... ! .... ], ,- ......
....................._.. i S.p._c#47.oo . _......................_.................._-_=-_-.3...................................
: 3 Cycies 5 cy_cles -_.... ^o,_,,,,o/_6.00 :-......................-'.............._.'.T..T. ........R_-u=: ........,=..7=.-.=u.:/=_
ii!, i!iiiiiiiiiiiiiiiiiii:ii:iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiill4.00 .......
1.00
o.oo .... ;,,,, i .... J .... j , , , ,0.000 0.010 0.020 0.030 0.040 0.050
Deflection (in)
Fig. C.1 - Load versus Deflection Hysteretic Response of Specimen #4 underFatigue Loading
12.00 ........... ! .... I ....spec#121
10.00 .......................-........................_.................A2%S3 .............i........................i.. , ! Range: 10_/o-90%_i_ycle ! i . i
8.oor-....................i:7"t:5!cycles........i----23cyo,es...................
................, .........i......................i.........................i......................i0 4.00 ........................ _..................;.........................;.......................
2.00
0.000.000 0.010 0.020 0.030 0.040 0.050
Deflection (in)
Fig. C.2 - Load versus Deflection Hysteretic Response of Specimen #12 underFatigue Loading
278
12.00 Spec #1_ iL_ .................;10.00
_, iiiiiiii_i!,_, 8.00 ...............................................................=o= s.oo i l...,I 4.00 F / I N, : 2[i. • i "
2.000.000.000 0.020 0.040 0.060 0.080
Deflection (in)
Fig. C.3 - Load versus Deflection Hysteretic Response of Specimen#1S underFatigue Loading
8,0 ......... , ......... i .........Specimen #.5
7,0 ---_-2%-s_..........t..................... t.................................Range: 10%-80% i
6.0 ......................................i......................T_O-_yc]__...............
E 5.0 ...............i_ .........................
4.0 ........::::........ii!!!::::::::::::::::::::::::::::::::::::_,o_.o ............:T2.0__ ................h_;:_l ....1.0 ,,,__ ...... _ T ,....
0.0 '''' ..... i ......... I .........0.000 0.005 0.010 0.015
Deflection (in)
Fig. C.4 - Load versus Deflection Hysteretic Response of Specimen #5 underFatigue Loading
279
14.00 ' ' ' #1"2" ' ' ' .........Spec . i2.oo _A_:_s_:s5............_........................................................................
Range:j 10%-80%10. 00 "_"_;_i_'"'3"OO0'-c_6000-_C, yC1m_........_......................-v j y : : i "
8.00 ........................... i ..................' ..................i......................"o 500 c cles010 6.00.J
..oo ................,.oo0.000.000 0.010 0.020 0.030 0.040 0.050
Deflection (in)
Fig. C.5 - Load versus Deflection Hysteretic Response of Specimen #21 underFatigue Loading
10.00 ......... I ......... I ........
Spec #10 j !A2%S38.0 0 -Range ._.....t-0%--70%.........................."........................................
[Pre-cracking_: IJ- cycle J-i 1000 cyc es 75000 cycles6.00 ....................................i............................._....................................
°' 4'002.00j-11: __-'-...... i_ _ i.!N+_.iiiii:i:iiiiiiiiii:!0 cycles -
o.oo _- l:0.000 0.010 0.020 0.030
Deflection (in)
Fig. C.6 - Load versus Deflection Hysteretic Response of Specimen #10 underFatigue Loading
280
12.00 I-1"Spec..................._24 iLA2%S3S5 ! i
1o.oo ,.g;;;;_iT;i6g:_ii_..................T.........................i.......................- i le I 0_)0 cyclesi 11950001 cycles" 3 cy.c s : _..................................... '_; ................... : ................. t ......................
=__,.oo i i i......................_. _ _.............. • ..............;.......................
,.o..iom6.00 i ]4.00 "" "-_/_1"__""
,oo ..................... "I , , , , "r .... I , , , , I ....0.00
0.000 0.005 0.010 0.015 0.020 0.025
Deflection (in)
Fig. C.7 - Load versus Deflection Hysteretic Response of Specimen #24 underFatigue Loading
281
0.050 ' ' ' i ............Spec #4Mix A.2%S3
,... 0.040 'Fatlggi"l:oudlrfg ......................................................................= Range:i 10% to J90%
0,030 ................................................'.....................................................................c:o
im
u 0,020 ....................-.........P.rna ...........---.......................................
0,010 ............................................................
0.000 .... ; ' ' '0 2 4 6 8 10
Number of Cycles
Fig. C.8 - Variation of Deflection versus Number of Cycles for Specimen #4
0.070 ......... i ..................
Spec #20 i0.060 ""A'2"%S'2S3"......i................................................................................
,-.. Fatigue Loading._c 0.050 -'RangeT"l-0%"i-to--80% ..................T........................................
¢ 0,040 ........................................,...................._ma)_......+........................................
ou 0,030 ..................................4)
mqm
a) 0,020
D _80.010 ...................................................................................
Nf = 150000. 000 ...................... '''''
0 5000 10000 15000
Number of Cycles
Fig. C.9 - Variation of Deflection versus Number of Cycles for Specimen #20
282
0.050 ,,, ] ...............
Spec I #10A2%S3
0.0 40 -F_.__'_-L_'dr_ ....................................................................._c Range: 10% to 70%
0.030 .............................................................................................................
o Pmax,,i=,l
o 0 020
_- ! Pmin
0.010 _ :
Nf = 1081950.000
0 40000 80000 120000
Number of Cycles
Fig. C.10 - Variation of Deflection versus Number of Cycles for Specimen #10
0.050 ...........................Spec #24A2%S3S5
0.040 --Fattgue--EoadFng ............................................................¢ Range: 10% to 70%
°o.O_Oo......................................................................1N,=,,,oo_.lu 0 020 ..................................._o •"a) ... _.:._:. -e---'q_-_" j
0.010 _ ......i i
o. ooo ......... i ......... i .........o.o 1000000.0
Number of Cycles
Fig. C.11 - Variation of Deflection versus Number of Cycles for Specimen #24
283
0.050 .... ! .... i ................Speci #9 i
0.040 -..A2.PA,J_3..............i ..................................................................................-. FatigUe Loading
tm_ , .•- Rang_: 7.5.%-52.0%"" 0.030 ..........................................................................................................................
c Pmax.- 0.020 .................._..............................................................................._..................
= o.o,oC...............i....................[....................O. 000 _ ....... _...................._...........z_.._..................
.o.o_o _.... i .... j .... i ........ i ....0 2000000 4000000 6000000
Number of Cycles
Fig. C.12 - Variation of Deflection versus Number of Cycles for Specimen #9
12.00 .... I .... I .... I .... [ ....Static iTest Aftbr Fatig0e Loading
10. 0 0 _..5.2.Z.6.02.'8.........(_.y..(;.I._.ll...................................................................Spec #9 j,/"_ _
'o 6.00mo
_ 4.00
0.000.00 o.01 0.o2 o.o3 0.o4 o.o5
Deflection (in)
Fig. C.13 - Load Versus Deflection Response after Fatigue Loading forSpecimen #9
284
0.020 , , , i ............
Spec i#4Mix A_2%S3
o. o16 ....F_ii_ii_----L-_-aii;i-O.........................................................................c Rangei 10% tO 90%em
....'S_:_.o12 .......................i {
c 0 008 "i'_ P_ax................................................. -.....................i........................;.......................
............ .............0.000 ,,, i,,, J.,, i , , , , , ,
0 2 4 6 8 10
Number of Cycles
Fig. C.14 - Variation of Strain versus Number of Cycles for Specimen #4
0.020 .... ! ........................Spec: #5A2%!S3
o. o16 'FJ._eT.:_-em__...".................i.........Z'..."............_ ...............E Ran e: 10 to 0% _'
._= 0.012 ...............;..................;................._................;...............;............._.........................................................., ..............or)
o.oo, '2_......................................o.ooo __T,,,, ; .... i .... ; .... ; .... ; ....
0 1000 2000 3000
Number of Cycles
Fig. C.15 - Variation of Strain versus Number of Cycles for Specimen #5
285
0.020 ......... i ..................
Spec #20 iA2%S2S3 i
A o.o16 .....¢;;ii_;_[6_;]]fi_........................................................................c Range: 10%1 to 80%in
" 0 012 ........................................;................................................................................
" 0 008 ......................................lm •mk,,
o.oo, ...............................................................ooiNf= 150i j0. 000 ....................... ''''
o 5000 10000 15000Number of Cycles
Fig. C.16 - Variation of Strain versus Number of Cycles for Specimen #20
0.005 .... i ................Spec i#9A2%8_3
O. 004 ....Puttglz.D'-t;oa'dlng .....................................................................c Range_: 7.5%.52.0%
•m
c 0.003 ............................................................................................................................
e-"- 0.002 ...........................................................................................................................I,,,
(n
0.001 ............................................._._.................i....................._........................
-- i i i i0,000 .... ' .... I .... I .... ,,,,,
0 2000ooo 4ooooooNumber of Cycles
Fig. C.17 - Variation of Strain versus Number of Cycles for Specimen #9
286
0.01 0 .... I ................Spec #17A2%S3S5
o. oo8 'Fi_T___X:_idr_i ..................................................................._ Range'_ 7.1%-57.0%
c 0.006 ............................................................................................................................palm
e-•"- 0.004 ...............................................-...........................................................................L_
0.002
0.0000 2000000 4000000
Number of Cycles
Fig. C.18 - Variation of Strain versus Number of Cycles for Specimen #17
287
1 2.00 ......... I ..................Static Test After Fatigue Loading
10. 0 0 ..5..2..7....6...0...2..8............C..y._.!..e....s.........................................................................Spec #9 _ iAGO/.R
_ o.oo -----.-----::------- ................................"o 6.00¢g0
"_ 4.00
2,00
o.oo ..... !.... i ......... ; .........0.000 0.005 0.010 0.015
Slrain (in/in)
Fig. C.19 - Load Versus Strain Response after Fatigue Loading for Specimen #9
20.00 ' ' ' t ' ' ' _ ' ' ' t ' ' ' J ' ' 'Static Test Afte_r Fatiguis Loadin_g5000000 Cyclds
1 6.0 0 -Spec-..--#l--7................_...........................................................................A2%S3iS5
_,12.00 ...............................................................................................................
m
o.oo 12111111,.j •
4.0O
0.00''' _ ' ' _,,, ,,,, 1 , , ,0.00 0.02 0.04 0.06 0.08 0.10
Strain (in/in)
Fig. C.20. Load Versus Strain Response after Fatigue Loading for Specimen #17
288
8.007.00
600
_'_ 5 O0
"_m 400
o 300
200
IO0
0000.00 0.05 0.10 0.15 0.20 0.25
Deflection (in)
Fig. C.21 - Load versus Deflection Response under Static Loading forSpecimen #I
8.00., ........... ] ............ I .... i .... -
7.oo ..........................................................................................spo¢...._3.......
.................A2..s..........."Ooe=400 i-J 3 00 ............_............................_............................._...............*...............;.............
oo1 O0 ....
0 O0 .... i .... , .... i .... I .... i .... i .... i ....0.00 0.10 0.20 0.30 0.40
Deflection (in)
Fig. C.22. Load versus Deflection Response under Static Loading forSpecimen #3
289
8.00 ............ j .... J ....
7.oo -/_..........._........................._.........................i............sp._._s........
.-. 6.00 _i! i i A2%63
5.00
o4.00 ial0
,.I 3.00 ....................................................................................._.......................
1.00
0 00 .... J ,,,, _, ,,, _, ,, , i, , , ,e
0.00 0.10 0.20 0.30 0.40 0.50
Deflection (in)
Fig. C.23 - Load versusDeflection Responseunder Static Loading forSpecimen #6
8.00 .... I ............................" I 1
7.00 ................ _...............:...............:...............:.........S c.....#7...........• i i i i ! A2%S3i
6.00
_" 5.00
•0 4.00m
-I 3.00 ............:...............:............_-..............._..............._..............._..............._............
2.OO
I .00
0.000.00 0.10 0.20 0.30 0 40
Deflection (in)
Fig. C.24 - Load versus Deflection Response under Static Loading forSpecimen #7
290
10.00
8.00 .........._. 6 00
o, 400
200
0.000.00 0.10 0.20 0.30 0.40 0.50
Deflection (in)
Fig. C.25 - Load versus Deflection Response under Static Loading forSpecimen #II
8.00 .... .... i ........ I ....
-/_.............:.........................i.........................i........s,p.e.c...!..#.n...........
,.oo _!i. ! i A_%s_s_oo_" 5.00
3.00 ......................_............... .
OOoo iiiiiiiiiiiiiiiiiiiii!iiiiiiiiiiiiiiiiiii iiiiiiiiiiiiiiiill0.000.00 0.10 0.20 0.30 0.40 o.so
Deflection (in)
Fig. C.26 - Load versus Deflection Response under Static Loading forSpecimen #13
291
10.00 ................ i ....
/'_ Sped #14
6.00 .............................................
"IDt_
oo0..I "
2.00 .........
0.00 ,,,, _ , , , I .... I .... i ....0.00 0.10 0.20 0.30 0.40 0.50
Deflection (in)
Fig. C.27 - Load versus Deflection Response under Static Loading forSpecimen #14
1500. ........ _ ............ I ....i
Spe¢i #19A2%I;3S5
i
,-.10.00.:¢
"at_
o i.J5.00 ...................................
0.00 ,,,, i, ....... i .... _ .... I ....0.00 0.05 0.10 0.15 0.20 0.25 0.30
Deflection (in)
Fig. C.28 - Load versus Deflection Response under Static Loading forSpecimen #19
292
20.00 ....
15.00
"0 10.00
0.-I
5.00
0.000.00 0.10 0.20 0.30 0.40 0.50
Deflection (in)
Fig. C.29 - Load versus Deflection Response under Static Loading forSpecimen #22
15.00 ................ ! ....
Spe F 023A2%S3S5
_.-,°.°°o.........i.........................i.........................i................................................m
0 i'iil .......i''''i......................0.00
0.00 0.10 0.20 0.30 0.40 0.50
Deflection (in)
Fig. C.30 - Load versus Deflection Response under Static Loading forSpecimen #23
293
8.00 ............ I ' ' '
_,%..................... spec .3.1............7. oo ............_2
oo_ 5.O0
•o 4.000
•.J 3.00
2111111111111111111111iliiiiiiiiiiiiiiiiiiiiii!iiiiiiiiiiiiiI . O0 ..........._.......................
, , , i , , , , , , , , , i , , ,0.00
0.00 0.04 0.08 0.12 0.16 0.20
Strain (in/in)
Fig. C.31 - Load versus Strain Response under Static Loading forSpecimen #1
8.00 ............ 1 ....i
7. oo _ .................................................................................._.,_e._....#...e......
_" 5.oo
•o 400_I0
•_ 3.00
,00 ii iiiiiiiiiiii1.00
0 00. .... I ........ , _ , ,0.00 0.05 0.10 0.15 0.20
Strain (in/in)
Fig. C.32- Load versus Strain Response under Static Loading forSpecimen #6
294
10.00 ........ I ............
Spec # 11
, A2%i3
-iiiiii....................... "° imo 4.00.,J
,,oo....................i.......................7i........................i.........................f.......................0.00 .... J , , , , J .... f .... _ , , , ,
0.00 0.01 0.02 0.03 0.04 0.05
Strain (in/in)
Fig. C.33 - Load versus Strain Response under Static Loading forSpecimen #11
8.oo_ sp_c,13 i7. O0 ............................. :.........................................................................
6.00
_" s.oo
4.00
o 3.00
2.0 0 ...................._........................"_.......................i.......................;......................_"
1.000.000.00 0.02 0.04 0.06 0.08 0.10
Strain (in/in)
Fig. C.34 - Load versus Strain Response under Static Loading forSpecimen #13
295
10 O0 ......... I ' ' '
/_ Spe¢ # 14
800 I ............_i ......................-....................A2-°_"S3S"5 ............
.J
20O
0 O0 J , , 1 , , , I , ,,0.00 0.04 0.08 0.12 0.16
Strain (in/in)
Fig. C.35 - Load versus Strain Response under Static Loading forSpecimen #14
15.00 ............ I ' ' '_:.
Spec #19
_,10.00 _ A2%S3S5 !"o¢lo_1
5.00 -
0.000.00 0.02 0.04 0.06 0.08 0.10
Strain (in/in)
Fig. C.36 - Load versus Strain Response under Static Loading forSpecimen #19
296
20.00
,__15.00 ............. i............
"010.000,,,J
5.00
0.000.00 0.04 0.08 0.12 0.16
Strain (in/in)
Fig. C.37 - Load versus Strain Response under Static Loading forSpecimen #22
15.00 ......... I ' '
Spec #23A2%S3S5
,...,10.00
IDcaO..J
5.00 --
0.00 , , . I , , , I , , , [ , , ,0.00 0.04 0.00 0.12 0.16
Strain (in/in)
Fig. C.38 - Load versus Strain Response under Static Loading forSpecimen #23
297
Concrete and Structures Advisory Committee
Chairman Liaisons
James J. MurphyNew York Department of Transportation (retired) Theodore R. Ferragut
Federal Highway Administration
Vice ChairmanHoward H. Newlon, Jr. Crawford F. JencksVirginia Transportation Research Council (retired) Transportation Research Board
Members Bryant MatherUSAE Waterways Experiment Station
Charles J. Arnold
Michigan Department of Transportation Thomas J. Pasko, Jr.Federal Highway Administration
Donald E. BeuedeinKoss Construction Co. John L. Rice
Federal Aviation Administration
Bernard C. Brown
Iowa Department of Transportation Suneei VanikarFederal Highway Administration
Richard D. GaynorNational Aggregates Association�National Ready Mixed Concrete 11/19/92Association
Expert Task GroupRobert J. Girard
Missouri Highway and Transportation Department Stephen ForsterFederal Highway Administration
David L. Gress
University of New Hampshire Amir Hanna
Gary Lee Hoffman Transportation Research Board
Pennsylvania Department of Transportation Richard H. Howe
Brian B. Hope Pennsylvania Department of Transportation (retired)
Queens University Susan Lane
Federal Highway AdministrationCarl E. Locke, Jr.
University of Kansas Rebecca S. McDaniel
Indiana Department of TransportationClellon L. Loveall
Tennessee Department of Transportation Howard H. Newlon, Jr.
David G. Manning Virginia Transportation Research Council (retired)
Ontario Ministry of Transportation Celik H. Ozyildirim
Robert G. Packard Virginia Transportation Research Council
Portland Cement Association Jan P. SkalnyW.IL Grace and Company (retired)
James E. Roberts
California Department of Transportation A. Haleem T_ir
American Association of State Highway and Transportation
John M. Scanlon, Jr. OfficialsW'_s Janney Elstner Associates
Lillian WakeleyCharles F. Scholer USAE Waterways Experiment StationPurdue University
7/22/93Lawrence L. Smith
Florida Department of Transportation
John R. Strada
Washington Department of Transportation (retired)