concrete mixture designs for o’hare modernization plan chicago o’hare january 12, 2006...

Concrete Mixture Designs for Concrete Mixture Designs for O’Hare Modernization PlanO’Hare Modernization Plan

Chicago O’Hare

January 12, 2006

University of Illinois (Urbana-Champaign)

Department of Civil and Environmental Engineering

jroesler

Change title to concrete mix design

Project GoalProject Goal

Investigate cost-effective concrete properties and pavement design features required to achieve long-term rigid pavement performance at Chicago O’Hare International.

Project TeamProject Team

Principal InvestigatorsProf. Jeff RoeslerProf. David Lange

StudentsCristian GaedickeSal VillalobosZach GrasleyRob Rodden

Project ObjectivesProject ObjectivesDevelop concrete material constituents and proportions for airfield concrete mixes

Strengthvolume stabilityfracture properties

Develop / improve models to predict concrete material behavior

Crack width and shrinkage

Evaluate material properties and structural design interactionsjoint type & joint spacing (curling and load transfer)Saw-cut timing

Project ObjectivesProject Objectives

Concrete properties

Long-term perfor-

mance at ORD

Material constituents and

mix design

Analysis of existing concrete mix designs

Laboratory tests

Optimal joint types and spacing.

ModelingTest for material properties

FY2005 AccomplishmentsFY2005 Accomplishments

Tech Notes (TN) - TN2: PCC Mix Design TN3: Fiber Reinforced Concrete for Airfield Rigid PavementsTN4: Feasibility of Shrinkage Reducing Admixtures for Concrete Runway PavementsTN11: Measurement of Water Content in Fresh Concrete Using the Microwave MethodTN12: Guiding Principles for the Optimization of the OMP PCC Mix DesignTN15: Evaluation, testing and comparison between crushed manufactured sand and natural sandTN16: Concrete Mix Design Specification EvaluationTN17: PCC Mix Design Phase 1

www.cee.uiuc.edu/research/ceat

TN2: PCC Mix DesignTN2: PCC Mix Design

Mix Id.Proposed Mix #1905

(2000)

Revised Mix #1905

(2000)

Mix #1933 (2000)

Proposed Mix #1994

(2000)

Mix K-5 003-

00(2004)Units

Water 280 262 280 262 258 lb/yd3Type I Cement 541 588 588 588 541 lb/yd3Type C Fly Ash 135 100 100 130 135 lb/yd3Coarse aggregate (# 57 Limestone, 1" max size. )

1850 1850 1850 1800 1840 lb/yd3

Fine aggregate 1125 1103 1115 1100 1117 lb/yd3Steel Fibers 0 0 0 85 0 lb/yd3Air entrainment admixture (Excel Air)

N/A 7 N/A N/A 6.8 oz/yd3

Water Reducer (Excel Redi Set)

29 15 28 29 30.4 oz/yd3

PropertiesProposed Mix #1905

Revised Mix #1905 Mix #1933

Proposed Mix #1904

Mix K-5 003-00

Units

W/CM 0.41 0.38 0.41 0.36 0.38 -fr7 N/A 788 802 N/A 770 psifr28 N/A 1030 842 N/A 855 psiAir 5-8 5-8 5-7 5-8 6.2 %Slump 2 3 +/- 1 3 +/- 1 3 +/- 1 1 in

Survey of Existing MixesSurvey of Existing Mixes

AirportCapital Airport

St. louis Lambert

St. louis Lambert

St. louis Lambert

St. louis Lambert

St. louis Lambert

St. louis Lambert

St. louis Lambert

St. louis Lambert

Fort Wayne

California

California

Mix Id. N/A Mix 1 F Mix 4 FMix 4 F

w/ fibers Mix 3 F Mix 5 F

Mix 5 F w/fibers

Mix 6 F Mix P 5 Mix 1 Mix 1 Mix 2

Water 233 250 258 258 248 258 258 258 250 218 300 258 lb/yd3Cement 490 510 535 535 354 310 310 372 680 288 489 479 lb/yd3

Type C Fly Ash 150 80 80 80 88 93 93 93 - 192 122 85 lb/yd3GGBS - - - - 148 217 217 155 - - - - lb/yd3

Coarse aggregate #1 1842 1866 1834 1834 1872 1808 1808 1836 1790 1424 1570 1400 lb/yd3Coarse aggregate #2 - - - - - - - - - 615 400 475 lb/yd3

Fine aggregate 1156 1225 1220 1220 1228 1232 1232 1206 1280 1198 1165 1310 lb/yd3Fibers - - - 3 - - 3 - - - - lb/yd3

Air entrainment admixture N/A 5.6 5.6 5.6 3 3.1 3.1 3.1 N/A N/A N/A 1.7 oz/yd3Water Reducer 19.6 14.2 14.2 14.2 17.7 18.6 18.6 18.6 N/A N/A N/A 16.92 oz/yd3

Materials PropertiesCement Type I I I I I I I I I I I IICoarse aggregate # 1 max. size. (in)

N/A 3/4" (#67) 3/4" (#67) 3/4" (#67) 3/4" (#67) 3/4" (#67) 3/4" (#67) 3/4" (#67) 3/4" (#67) 1" (57) 1" (57) 1" (57)

Coarse aggregate # 2 max. size. (in)

- - - - - - - - - 3/8" 3/8"1/2 x #4"

Fine aggregate type N/ARiver Sand

River Sand River SandRiver Sand

River Sand

River Sand

River Sand

River Sand

N/A,FM= 2.68

N/A,FM= 2.96

Sechelt Sand

AEA type AEA GracePolychen AE VRC

Polychen AE VRC

Polychen AE VRC

Polychen AE VRC

Polychen AE VRC

Polychen AE VRC

Polychen AE VRC

GRT AEA N/A N/A MBAE

WR typeDaracem Grace

Polychen MC 400

Polychen MC 400

Polychen MC 400

Polychen MC 400

Polychen MC 400

Polychen MC 400

Polychen MC 400

GRT KB 1000

N/A N/APozz 200N

Fiber type - - -GRT Polymesh fibers

- -GRT Polymesh fibers

- - - - -

Concrete Properties Units W/CM 0.36 0.42 0.42 0.42 0.42 0.42 0.42 0.42 0.37 0.45 0.49 0.46 -fr28 770 1033 850 905 700 675 675 675 1280 N/A N/A 767 psiAir 5.5 7.6 7 7 5 5 5 5 6 N/A N/A 3 %

Slump 4 1/2" 2" 3 3/4 " 3 3/4 " 1 1/4 " 3" 3" 3" 1 1/2" N/A N/A 3 1/4" in

Tech Note 3Tech Note 3

Fiber Reinforced Concrete for Airfield Rigid Pavements

0

25

50

75

100

125

150

175

200

225

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Average Interior Maximum Surface Deflection (mm)

Lo

ad

(k

N)

Plain

0.48% Synthetic Macro Fiber

0.32% Synthetic Macro Fiber

Final cost: reduction of 6% to an increase of 11%


Feasibility of Shrinkage Reducing Admixtures for Concrete Runway Pavements

Reduced Shrinkage and Cracking Potential ~ 50% reduction

Cost limitations (?)

Figure 1. Unrestrained shrinkage of mortar bars, w/c = 0.5 (Brooks et al. 2000)


Measurement of Water Content in Fresh Concrete Using the Microwave Method

Strengths: quick, simple, and inexpensive

Limitations: need accurate information on cement content aggregate moisture and absorption capacity

TN 12: Guiding Principles for the TN 12: Guiding Principles for the Optimization of the OMP PCC Mix DesignOptimization of the OMP PCC Mix Design

1st order:Strength, workability

2nd Order:Shrinkage, fracture properties

LTE & strength gain


Evaluation, testing and comparison between crushed manufactured sand and natural sand

Gradation

physical properties

Material BSG(ssd) BSG(dry) AC(%)Bulk density dry(kg/m3)

Bulk density ssd(kg/m3)

% Voids

Manufactured sand 2.7 2.63 2.59 1628 1670 38.1Natural sand 2.43 2.38 2.15 1703 1740 28.3

ASTM C-29ASTM C-128

Gradation According to ASTM C-33

0

20

40

60

80

100

200 100 50 30 16 8 4 0.375

ASTM SIEVE NUMBER

PE

RC

EN

TA

GE

PA

SS

ING

.

Manufactured Sand(ms)Natural Sand(ns)ASTM FineASTM Coarse

Finness Modulusms = 3.12ns = 2.64

Manufactured vs Natural SandManufactured vs Natural Sand

Visual evaluationMaterial retained in the #8 sieve shows difference in the particle shape

The Manufactured sand shows a rough surface and sharp edges due to the crushing action to which it was subjected.

4mm

4mm

500m

500m

Sieve No. 50Sieve No. 8


Concrete Mix Design Specification Evaluation

Preliminary P-501 evaluation

Strength, shrinkage, and material constituent contents

P-501 Guidelines Our View

max w/cm = 0.50 Ok

Min cement content = 500 lb/yd3 This could be lower min flexural strength = 600 psi @ 28 d 700 ok, could be 90 d

fly ash content range = 10-20% Ok fly ash + slag range = 25-55% Ok

max slag when temp < 55 F = 30% Ok air content = 5.5% for 1.5" topsize CA Ok air content = 6.0% for 0.75" topsize CA Ok

2005 Accomplishments2005 Accomplishments

Specification Assistance

On-site meetings at OMP headquarters

Brown bag seminars

Continued specification assistance (2006): Material constituents (aggregate type and size, SCM, etc.)

Modulus of rupture and fracture properties of concrete

Shrinkage (cement content, w/c ratio limits,etc.)

Saw-cut timing, spacing and depth

Pavement design

PCC Mix Evaluation – Phase IIPCC Mix Evaluation – Phase II

Effect of aggregate size (0.75” vs. 1.5”)

Effect of 1.5” coarse aggregate:Total cementitious content: 688 lb/yd3, 571 lb/yd3, 555 lb/yd3 and 535 lb/yd3

Water / cementitious ratio: 0.38 versus 0.44

Fly Ash / cementitious ratio: 14.5% versus 0%

Effect of coarse aggregate cleaniness

PCC Mix Evaluation – Phase IIPCC Mix Evaluation – Phase II

TestingFresh concrete properties

Slump, Air Content, Unit Weight

Mechanical Testing Compressive strength (fc) at 7 and 28 days Modulus of Elasticity (E) at 7 and 28 days Split tensile strength (fsp) at 7 and 28 days Modulus of Rupture (MOR) at 7 and 28 days

Volume Stability Testing Drying and Autogenous Shrinkage trends for 28+ days

Fracture tests Early-ages (<48 hrs) Mature age (28 days)

Mixture design nomenclatureMixture design nomenclature

9 mixes were prepared:

555.44 – 555.44 st – 688.38 – 688.38 st

AAA.BB **

Cementitious content (17%FA)

lbs/cy

w/cm**max aggregate size

st = 0.75”

Otherwise 1.5”

Phase II Mix Design ResultsPhase II Mix Design Results

ID

688.38 (1.5" CA) CLEAN

AGG

688.38 standard (3/4 " CA)

688.44 (1.5" CA)

688.38 (1.5" CA)

571.44 (1.5" CA)

571.38 (1.5" CA)

571.44 Nof (1.5" CA)

535.44 (1.5" CA)

555.44 (1.5" CA)

water (lb/yd3) 261 262 303 261 251 217 251 235 244cement (lb/yd3) 588 588 588 588 488 488 571 535 455fly ash (lb/yd3) 100 100 100 100 83 83 0 0 100

CA (lb/yd3) 1842 1850 1772 1842 1924 1982 1938 1984 1942FA (lb/yd3) 1083 1103 1042 1083 1132 1166 1140 1167 1142

AEA (oz/yd3) 19.4 12.7 19.4 19.4 16.1 16.1 16.1 15.1 15.6w/cm 0.38 0.38 0.44 0.38 0.44 0.38 0.44 0.44 0.44

CA/ FA 1.7 1.68 1.7 1.7 1.7 1.7 1.7 1.7 1.7cm 688 688 688 688 570.96 570.96 571 535 555w/c 0.44 0.45 0.51 0.44 0.51 0.44 0.44 0.44 0.54Fl\y Ash/ CM 0.15 0.15 0.15 0.15 0.15 0.15 0.00 0.00 0.18

Slump (in) 6.13 7.63 9.00 6.25 7.38 2.50 2.25 8.63 7.88Air (%) 7.0 6.5 6.0 8.0 2.9 7.3 6.5 2.9 3.7

Density (pcf) 143.8 145.1 141.8 141.8 150.4 143.9 146.2 150.9 150.2

fs7 (psi) 362 526 275 440 412 416 505 390 480

fs28 (psi) #¡DIV/0! 570 423 454 513 429 524 415 490

fc7 (psi) 3,393 4,045 3,267 3,241 3,608 3,369 3,329 2,338 3,327

fc28 (psi) #¡DIV/0! 4,217 4,131 3,785 4,344 3,744 5,366 3,369 4,212

Ec7 (psi) 3,236 3,476 4,177 4,031 3,879 4,224 3,326 3,426 3,692

Ec28 (psi) #¡DIV/0! 3,752 3,695 3,438 4,204 3,881 3,958 3,311 4,209 MOR28 (psi) #¡DIV/0! 802 668 639 688 651 794 619 663

Strength SummaryStrength Summary

Mixture ID 688.38ST 688.38 571.44 555.44 fsp28 (psi) 570 454 524 490 MOR28 (psi) 802 639 794 663

E28 (ksi) 3,752 3,438 3,958 4,209

Mixture ID 688.38ST 688.38 571.44 555.44 Coarse Aggregate Size (in) 0.75 1.5 1.5 1.5 Coarse Aggregate (lb/yd3) 1850 1842 1938 1942

Fine Aggregate (lb/yd3) 1103 1083 1140 1142 Water (lb/yd3) 262 261 251 244

Cement (lb/yd3) 588 588 571 455 Fly ash (lb/yd3) 100 100 0 100

Air (oz/yd3) 12.7 19.4 16.1 15.6 Slump (in.) 7.5 6.25 2.25 8.0

Air Content (%) 6.5 8 6.5 3.7 Unit Weight (lb/ft3) 145.1 141.8 146.2 150.2

Shrinkage Results Phase IIShrinkage Results Phase II

Total and Autogenous shrinkageExperimental Shrinkage Data for all Mixes

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0 5 10 15 20 25

Age of Concrete (days)

Sh

rin

ka

ge

(m

m/m

)

688.38ST Total 688.44 Total 688.44 Autog. 688.38 Total

688.38 Autog. 571.44 Total 571.38 Total 571.38 Autog.

571.44 NF Total 535.44 Total 555.44 Total

Drying Shrinkage – Phase IIDrying Shrinkage – Phase II

Total Shrinkage vs. Age

0

100

200

300

400

500

0 5 10 15 20 25 30Concrete Age (days)

Sh

rin

kag

e (m

icro

stra

in).

.

688.38 st

688.38

571.44

555.44

\

Mixture ID 688.38 st 688.38 571.44 555.44

sh3 (microstrain) 48 118 139 52

sh7 (microstrain) 193 233 250 158

sh14 (microstrain) 292 338 320 273

sh28 (microstrain) 417 405 380 335

Fracture Energy – Phase IIFracture Energy – Phase II

GF = cracking resistance of material

GF = joint surface roughness indicatorLoad vs Displacement

0

500

1000

1500

2000

2500

3000

3500

4000

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1CMOD (mm)

Lo

ad

(N

)

PeakLoad

GF = Area under the Curve Cracking Area

WST Test WST Test

30mm

57mm

2mm

Notch detail

200 mm

205mm

200 mm

80mm 40mm 80mm

The WST Specimen

a

b

= a/b

t

Testing Plan – 4 MixturesTesting Plan – 4 Mixtures

Wedge splitting specimens (7) 6, 8, 10, 12 and 24 hours

7 and 28 days

Cylinders for compression and split tensile strength for 1,7 and 28 days and E values for 7 and 28 days

MOR for 28 days

Fracture Plots of PCC mixturesFracture Plots of PCC mixtures

688.38st

0

500

1000

1500

2000

2500

0 0.2 0.4 0.6 0.8 1COD(mm)

Fo

rce(

N)

6hrs

8 hrs

10 hrs

12 hrs

1 day

7 day

28 day

688.38

0

500

1000

1500

2000

2500

0 0.2 0.4 0.6 0.8 1

COD(mm)

FO

RC

E(N

)

6hrs

8hrs

10hrs

12hrs

1 day

7 day

28 day

555.44

0

500

1000

1500

2000

2500

0 0.2 0.4 0.6 0.8 1

COD(mm)

FO

RC

E(N

)

8 hrs

10 hrs

12 hrs

24 hrs

7days

28 days

555.44st

0

500

1000

1500

2000

0 0.2 0.4 0.6 0.8 1

COD(mm)

FO

RC

E(N

)

6hrs

8hrs

10hrs

12 hrs

1 day

7 day

688.38st

0

500

1000

1500

2000

2500

0 0.2 0.4 0.6 0.8 1COD(mm)

Fo

rce(

N)

6hrs

8 hrs

10 hrs

12 hrs

1 day

7 day

28 day

688.38

0

500

1000

1500

2000

2500

0 0.2 0.4 0.6 0.8 1

COD(mm)

FO

RC

E(N

)

6hrs

8hrs

10hrs

12hrs

1 day

7 day

28 day

555.44

0

500

1000

1500

2000

2500

0 0.2 0.4 0.6 0.8 1

COD(mm)

FO

RC

E(N

)

8 hrs

10 hrs

12 hrs

24 hrs

7days

28 days

555.44st

0

500

1000

1500

2000

0 0.2 0.4 0.6 0.8 1

COD(mm)

FO

RC

E(N

)

6hrs

8hrs

10hrs

12 hrs

1 day

7 day

Fracture Energy Results-Phase IIFracture Energy Results-Phase II

Age = 28-days Load vs. CMOD curves for Wedge Splitting Samples

0

500

1000

1500

2000

2500

3000

0 0.5 1 1.5 2

CMOD(mm)

Fv

(N)

688.38st

688.38

555.44

Mixture ID 688.38 st 688.38 571.44 555.44

GF (Nm) 156 166 N/A 161

Concrete BrittlenessConcrete Brittleness

Characteristic Length2fsp

EGl Fch

Mixture ID 688.38ST 688.38 571.44 555.44 fsp28 (psi) 570 454 524 490 E28 (ksi) 3,752 3,438 3,958 4,209

GF (Nm) @ 28-day 156 166 N/A 161 lch (in) 10.3 15.8 N/A 16.1

Less brittle mixes w/ larger MSA

Fracture Energy Shear Stiffness

Joint Performance

*need crack width!

GGFF vs Joint Performance vs Joint Performance

Chupanit & Roesler (2005)

Mixture ID 688.38ST 688.38 571.44 555.44

MOR28 (psi) 802 639 794 663

GF (Nm) @ 1-day 111 155 N/A 126 GF (Nm) @ 28-day 156 166 N/A 161

PCC Mix Design – Phase IIPCC Mix Design – Phase II

Summary*Larger aggregates reduce strength by 20%

28-day GF similar similar cracking resistance

Larger aggregates reduce concrete brittleness

1-day fracture energy with larger MSA greater joint stiffness / performance

No significant shrinkage difference

TNXX – February 2006*Roesler, J., Gaedicke, C., Lange, Villalobos, S., Rodden, R., and Grasley, Z. (2006), “Mechanical Properties of Concrete Pavement Mixtures with Larger Size Coarse Aggregate,” accepted for publication in ASCE 2006 Airfield and Highway Pavement Conference, Atlanta, GA.

Saw-cut timing and depthSaw-cut timing and depth

Stress analysis of slab (temp & shrink)

Size Effect (fracture) Model

Concrete Material Fracture Parameters Wedge Splitting Test @ early ages

No method to obtain Critical Stress Intensity Factor (KIC) and Critical Crack Tip Opening Displacement (CTOCC) for WST

FEM MODEL FOR THE WST SPECIMEN

200 mm

205mm

200 mm

80mm 40mm 80mm


Fracture Parameters WST specimen

30mm

57mm

2mm

Notch detail

ab

= a/b

t


FEM Model Special Mesh around crack tip

Q8 elements

Symmetry and BC consi-derations

200

mm100 mm


FEM Model Stress around crack tip

Calculation of KI

Quarter point nodes

FEM ANALISYSFEM ANALISYS

)(f *b*t

P K 11/2

smaxIC

)(f*E*t

PCMOD 2

sp

CMOD*)(fCTOD 3

Psmax = peak splitting load

KIC = critical SIF

CTODc= critical CTOD

CMODc= critical CMOD

f1() = geometrical factor 1



E = modulus of elasticity

Gf = initial fracture energy

E

KG IC

f

2

FEM MODELING OF THE WST

2*

32

IC

Cf K

ECTODc

Evolution of GEvolution of GFF vs Age vs AgeFracture energy Vs Age

0

25

50

75

100

125

150

175

0 5 10 15 20 25

Age(hours)

Gf(

N-m

)

555.44

555.44st

688.38

688.38st

1.5” max aggregate size

Fracture energy Vs Age

0

20

40

60

80

100

120

140

160

180

200

1 10 100 1000

Age(hrs)

Gf(

N-m

)

555.44

555.44st

688.38

688.38st Large increase in GF between 8 and 24 hrs (saw-cutting operations).

Saw-Cut Timing ModelSaw-Cut Timing Model

Concrete E and fracture properties(cf ,KIC) at early ages.

Using Bazant’s Size Effect Model to analyze finite size slabs.

Develop curves of nominal strength vs notch depth for timing.

Nominal strength vs ao/d for the 300mm slab

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0.000 0.100 0.200 0.300 0.400 0.500 0.600

ao/d

No

min

al s

tren

gth

ls@6hr

ls@12hr

rg@6hr

rg@12hr

•After Soares (1997)

Joint Type AnalysisJoint Type Analysis

How can we rationally choose dowel vs. aggregate interlock joint type & joint spacing?

Need to predict crack width & LTEShrinkage, zero-stress temperature, creep

Aggregate size and type (GF)

Slab length & base friction

Reduced aggregate interlock with Reduced aggregate interlock with small max. size CAsmall max. size CA

Crack width, w

Dowels deemed necessary

Larger max. size CALarger max. size CA

Larger aggregate top size increases aggregate interlock and improves load transfer

Crack width, w

Crack Width Model ApproachCrack Width Model Approach

Step 1: Predict crack opening, w

Step 2: Predict differential

deflection, δdiff

Step 3: Determine

LTE

Inputs:RH, T, L, E, , C

Inputs:w, CA topsize,

Step 4: Acceptable

LTE?

Inputs:δfree, δdiff,

Inputs:FAA

recommendation

iPCC

i

PCCiSHRi E

fcTLCCCW

i

2

fL

hC

dc

PULf

bi

m

2

210

1i

Base frictionCurling (thermal and moisture)Steel reinforcement

Crack spacing

Drying shrinkage

Temperature drop

Restraints

*after DG2002

Step 1: Predicting crack width Step 1: Predicting crack width opening, wopening, w

Average increase with age due to shrinkage

Future Joint Analysis QuestionsFuture Joint Analysis Questions

What is an acceptable LTE?

What is LTE when dowels are removed?

Can joint spacing be increase from 18.75 to 25 ft?

How much can LTE be changed by concrete property changes?

Literature ReviewSurvey of existing mix designsReview of mix design strategies

Volume Stability TestsDrying and Autogenous shrinkageOptimization of concrete mixes to reduce volumetric changes

Strength TestingModulus of rupture, splitting and compressive strengthFracture energy and fracture surface roughness

Project Tasks and ProgressProject Tasks and Progress

Done,

TN2, 3, 4, 15

Done, TN 12

Done

Done,

TN 12 and TN 17.

Done, TN 12, TN 17, conf. paper

Fracture Tests Done

Status


Joint Type Design Slab size and jointing plans: productivity, cost, performance.

Optimization of concrete aggregate interlock to ensure shear transfer.

Joint (crack) width prediction model for concrete materials.

In progress, TN 3. Analysis pending, fracture and shrinkage tests done.

In progress, TN 12. Fracture tests

In progress


Saw-cut timing and depthSaw-cut timing criteria for the expected materials

Analytical model / Validation

Fiber Reinforced Concrete Materials

Overview of structural fibers for rigid pavement

Literature Review done, TN 3.

FEM model developed to obtain fracture results from WST samples, currently applying results to determine saw-cut timing and depth.

New Work for FY2006New Work for FY2006

Functionally-layered concrete pavementsMulti-functional rigid pavement

Cost saving

GREEN-CRETE Recycled concrete aggregate

Effect of recycled aggregate on mechanical and volumetric properties of concrete

Current work:Current work:Recycled Concrete as Aggregates (RCA) Recycled Concrete as Aggregates (RCA)

for new Concretefor new Concrete

Recycled Concrete AggregateRecycled Concrete Aggregate

Use of RCA for OMPUse of RCA for OMP

RCA may lead to cost savingsDisposal costs

Trucking costs

Natural aggregate costs

RCA may increase shrinkage?RCA less stiff than natural aggregate

RCA can shrink more than natural aggregate

Shrinkage may be same or reduced if RCA is presoaked to provide internal curing

UIUC First TrialUIUC First Trial

RCA from Champaign recycling plantConcrete came from pavements, parking garages, etc.

Mix of materials with unknown properties

Material washed, dried, and sieved to match natural fine aggregate

Soaked for 24 hrs, surface dried, and then 100% replacement of natural fine aggregate

Saturated RCA vs Lab AggregatesSaturated RCA vs Lab Aggregates

-100

-80

-60

-40

-20

0

20

0 5 10 15 20

Age (d)

Shr

inka

ge s

trai

n x

10-6 lab stock

lab ssdRCA SSD

•Similar autogenous shrinkage curves

RCA Summary to DateRCA Summary to Date

Optimization of RCA gradation may lead to reduction in overall shrinkage

Other concerns:Reduced concrete strength and modulus

Potential for ASR from RCA?

Source of chlorides to cause corrosion of dowels?

Future work - use RCA with known propertiesTry different gradations

Measure strength/fracture properties also

Functionally LayeredFunctionally Layered Concrete Pavement Concrete Pavement

T, RHP

E(z), υ(z), α(z), k(z), ρ(z), D(z)h

z

Wear Resistant

Shrinkage Resistant

Fatigue Resistant

Support Layers

Functions

Shrinkage Resistant Layer

Support Layers

No fibers

fB = 0.1%

fA = 0.25%

fA = 0.5%

h1, E1, υ1, α1, k1, ρ1, D1

h2, E2, υ2, α2, k2, ρ2, D2

h3, E3, υ3, α3, k3, ρ3, D3

h4, E4, υ4, α4, k4, ρ4, D4

Porous Concrete Friction/Noise Layer

Fatigue Resistant Layers

Functionally Layered Functionally Layered Concrete PavementConcrete Pavement

Experimental Program:

P

h

CMOD

Bottom layer

Top layer

ao

h1

h2

(a) (b)

Bottom layer

Top layer

Configuration ID PCC/PCC PCC/FRCPP FRCPP/PCC FRCPP/FRCPP PCC / FRCCS

FRCCS

/ PCC FRCCS / FRCCS

Top layer (h1) PCC PCC FRCPP FRCPP PCC FRCPP FRCPP Bottom layer (h2) PCC FRCPP PCC FRCPP FRCPP PCC FRCPP Type of specimen TPB WST TPB WST TPB WST TPB WST TPB TPB TPB # of specimens 3 / 3 2 3 2 3 2 3 2 3 3 3


Structural Synthetic Fibers in Beams

P

h

CMOD

Bottom layer

Top layer

ao

h1

h2


Steel Fibers in Beams

P

h

CMOD

Bottom layer

Top layer

ao

h1

h2


Synthetic Fibers in WST Specimen


Recycled Concrete Aggregate (RCA)

Review of previous experiences with RCA

Experimental program, and test to determine effect of RCA on relevant mix properties

In progress

In progress


Functionally Layered Concrete Pavement

Overview of structural fibers for rigid pavement

Layered pavement systems- preliminary study

Fracture resistance of two layer concrete pavement systems

Literature Review done, TN 3.

Done, preliminary results show potential

In progress

2006 First Quarter Deliverables2006 First Quarter Deliverables

TN - Phase II concrete mix evaluation

Large aggregate mixtures paper (ASCE)

TN – Fracture Properties of Concrete Mixtures (WST)


FEM Model Determination of Fracture parameters

1/21

smaxIC b*t

)(f *P K

)(f *

b*t

P K 11/2

smaxIC

f1 vs a/b

y = 9.8214x - 1.4584R2 = 0.9779

y = 25.598x2 - 15.757x + 4.8066R2 = 0.9996

2.0

2.5

3.0

3.5

4.0

4.5

5.0

0.40 0.42 0.44 0.46 0.48 0.50 0.52 0.54 0.56 0.58 0.60a/w

f1


FEM Model Determination of Fracture parameters

E*t

)(f *PCMOD 2

sp

)(f*

E*t

PCMOD 2

sp

CMOD*)(fCTOD 3 f2 vs a/b

y = 207.07x - 58.121R2 = 0.9736

y = 590.13x2 - 382.59x + 86.31R2 = 0.9995

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

0.40 0.42 0.44 0.46 0.48 0.50 0.52 0.54 0.56 0.58 0.60a/w

f2

f3 vs a/b

y = 1.2088x - 0.3456R2 = 0.9847

y = -3.3883x2 + 4.7542x - 1.2625R2 = 0.9991

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.40 0.42 0.44 0.46 0.48 0.50 0.52 0.54 0.56 0.58 0.60a/w

f3

Recycled Concrete AggregateRecycled Concrete Aggregate

Some findings from literatureWhen used with a very low w/cm, RCAC compressive strength can exceed 9000psi at 28 d

Autogenous shrinkage can be lowered by 60% by adding saturated RCA

While there are no reports in the literature, it is likely that RCA increases tensile creep, which would reduce propensity for

shrinkage cracking or curling

I. Maruyama, R. Sato, “A trial of reducing autogenous shrinkage by recycled aggregate”, in Proceedings of self-desiccation and its importance in concrete technology, Gaithersburg, MD, June 2005.

concrete mixture designs for o’hare modernization plan chicago o’hare january 12, 2006...

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