evaluation of the effect of recycle waste plastic …
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Road and Transport Engineering Thesis
2020-03-15
EVALUATION OF THE EFFECT OF
RECYCLE WASTE PLASTIC BAGS
(WPB) ON MECHANICAL
PROPERTIES OF HOT MIX ASPHALT MIXTURES
Assefa, Nakachew
http://hdl.handle.net/123456789/10313
Downloaded from DSpace Repository, DSpace Institution's institutional repository
BAHIR DAR UNIVERSITY
BAHIR DAR INSTITUTE OF TECHNOLOGY
SCHOOL OF RESEARCH AND GRADUATE STUDIES
FACULTY OF CIVIL AND WATER RESOURCES ENGINEERING
EVALUATION OF THE EFFECT OF RECYCLE WASTE PLASTIC
BAGS (WPB) ON MECHANICAL PROPERTIES OF HOT MIX
ASPHALT MIXTURES
By Nakachew Assefa
Bahir Dar, Ethiopia
March, 2019
EVALUATION OF THE EFFECT OF RECYCLE WASTE PLASTIC BAGS (WPB) ON
MECHANICAL PROPERTIES OF HOT MIX ASPHALT MIXTURES
Nakachew Assefa Kebede
A thesis submitted to the school of Research and Graduate Studies of Bahir Dar
Institute of Technology, BDU in partial fulfillment of the requirements for the degree
of
Master of Science in the Road and Transport Engineering in the Faculty of Civil & Water
Resource Engineering.
Advisor Name: Dr. Habtamu Melese (PhD, P.E)
Bahir Dar, Ethiopia
March 13, 2019
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ii
Bahir Dar University
Bahir Dar Institute of Technology
School of Research and Graduate Studies
Faculty of civil and Water Resource Engineering
THESIS APPROVAL SHEET
Student:
Nakachew Assefa
Name Signature Date
The following graduate faculty members certify that this student has successfully presented
the necessary written final thesis and oral presentation for partial fulfillment of the thesis
requirements for the Degree of Master of Science in Road and Transport Engineering.
Approved by:
Advisor:
______________________________________________________________________
Name Signature Date
External Examiner:
______________________________________________________________________
Name Signature Date
Internal Examiner:
______________________________________________________________________
Name Signature Date
Chair Holder:
____________________________________________________________________
Name Signature Date
Faculty Dean:
_____________________________________________________________________
Name Signature Date
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ACKNOWLEDGEMENT
I would like to thank those individuals who were the reason in the completion of this
research. Specially, I would like to thank my advisor, Habtamu Melese (PhD, P.E) for his
guidance, encouragement and patience. His support was greatly appreciated.
I would like to thank also BDU and ERA for giving this chance; all technical staff members
of Bahir Dar Institute of Technology, Faculty of Civil & Water Resource Engineering for
their help during laboratory experimental activities.
My special thanks go to CCECC laboratory staffs Mr. Liu and Mr. Hamid for borrowing
their laboratory equipment’s to use it in the university laboratory for conducting this
research.
I would like to give my deepest thanks to all my family members, friends and workmates
in their support and advice. My special appreciation also goes to Ms. Roza Erkihun for
being with me in every incident.
At last but not least, thanks to GOD with his mother for their unlimited blessings and for
giving me the strength to complete this study.
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ABSTRACT
Due to increasing of traffic volumes and loading repetitions in combination with an
insufficient degree of maintenance, surface distress like potholes, raveling of asphalt
surface and rutting has been observed on most of the asphalt roads. In addition, increase in
population with tremendous growth rate has led to disposal of large amount of non-
decaying waste materials which become also a great concern in developed as well as
developing countries. This study presents utilization of Waste Plastic Bag (WPB) as an
aggregate coat and evaluates its effect on the mechanical properties of hot mix asphalt
mixture with 9.5, 12.5 &19mm nominal maximum aggregate size.
Therefore, in this investigation, cleaned, dried and grinded WPB (size ranges from 2.36 to
4.75mm) has been introduced randomly to the asphalt mixture at different percentage of
WPB replacement content (i.e. 6, 9, 12, 15 & 18%) by the weight of optimum bitumen
content. The specimens were subjected to Marshall Hot Mix Design and Indirect Tensile
Strength (ITS) test. In total, 171 samples were prepared, 45 of which have been used to
determine the optimum bitumen content, 54 specimens were used to study the effect of
WPB, and the rest have been used to know the moisture susceptibility of the mix. The
results indicate that WPB can be used in asphalt mixtures with the optimum replacement
rate of 17, 13 and 7% for 9.5, 12.5 and 19mm nominal maximum aggregate size
respectively. At the optimum WPB replacement stability, flow, bulk density and voids are
within the local and international specifications. In addition, from ITS test it is observed
that the modified mix doesn’t susceptible to moisture damage.
For all nominal maximum aggregate size, based on the economic analysis using WPB in
asphalt mix is economically viable. The asphalt mix produced with incorporating waste
plastic bags are applicable on surfacing layers of flexible pavement structures. Asphalt mix
with 9.5mm nominal maximum aggregate size modified with plastic bags can be used as
surfacing layer for parking lots, 12.5mm can be used as wearing course layer and 19mm
also can be used as binder coarse layer.
Key Words: Nominal Maximum Aggregate Size, Waste Plastic Bag, Marshall Hot Mix
Design, Indirect Tensile Strength.
v
Table of Contents DECLARATION ................................................................................................................. i
ACKNOWLEDGEMENT ................................................................................................. iii
ABSTRACT ....................................................................................................................... iv
LIST OF ABBREVIATIONS ............................................................................................ vi
LIST OF FIGURES ......................................................................................................... viii
LIST OF TABLES ............................................................................................................. ix
CHAPTER ONE
1 INTRODUCTION .................................................................................................. 1
1.1 Background ....................................................................................................... 1
1.2 Statement of the Problem ................................................................................. 3
1.3 Objective of the Study ...................................................................................... 5
1.4 Scope and Limitation of the Study ................................................................... 5
1.5 Significance of the Study .................................................................................. 6
CHAPTER TWO
2 LITERATURE REVIEW ....................................................................................... 7
2.1 Introduction ...................................................................................................... 7
2.2 Hot Mix Asphalt Concrete ................................................................................ 8
2.3 Moisture Suscepibility of Hot Mix Asphalt ..................................................... 9
2.4 Plastic Polymers ............................................................................................. 10
2.4.1 Types of plastics ...................................................................................... 10
2.5 Laboratory studies on Utilization of Plastics in HMA ................................... 12
2.6 Summary ......................................................................................................... 14
CHAPTER THREE
3 METHODS AND MATERIALS .......................................................................... 16
3.1 Introduction .................................................................................................... 16
3.2 Materials Characteristics ................................................................................ 17
3.2.1 Aggregate ................................................................................................ 17
3.2.2 Asphalt Binder......................................................................................... 21
3.2.3 Waste Plastic Bags .................................................................................. 24
3.3 Experimental Work ......................................................................................... 26
3.3.1 Marshall Hot Mix Design ........................................................................ 27
3.3.2 Moisture Sensitivity of the Mix .............................................................. 29
CHAPTER FOUR
4 RESULT AND DISCUSSION ............................................................................. 31
vi
4.1 Optimum Bitumen Content Determination .................................................... 31
4.2 Marshall Properties of Asphalt Mixtures Contatining WPB .......................... 34
4.2.1 Effect of WPB on Bulk Density .............................................................. 34
4.2.2 Effect of WPB on Flow ........................................................................... 36
4.2.3 Effect of WPB on Stability...................................................................... 37
4.2.4 Effect of WPB on Air Void ..................................................................... 39
4.2.5 Effect of WPB on VMA .......................................................................... 40
4.2.6 Effect of WPB on VFA ........................................................................... 41
4.3 Optimum WPB Content Determination ......................................................... 43
4.4 Moisture Sensitivity of Asphalt Mixtures Conaining WPB ........................... 45
4.4.1 Tensile Strength Ratio (TSR) .................................................................. 45
4.4.2 Indirect Tensile Strength (ITS) Test........................................................ 46
4.5 Statistical Analysis ......................................................................................... 48
CHAPTER FIVE
5 ECONOMIC ANALYSIS .................................................................................... 55
5.1 Introduction .................................................................................................... 55
5.2 Recycling Opportunity and Challenges .......................................................... 56
5.3 Plastic Recycling ............................................................................................ 57
5.4 Cost-Benefit Analysis ..................................................................................... 59
CHAPTER SIX
6 CONCLUSION AND RECOMMENDATION .................................................... 64
6.1 Conclusions .................................................................................................... 64
6.2 Recommendations .......................................................................................... 65
6.3 Future Study ................................................................................................... 66
REFERENCES ............................................................................................................. 67
APPENDIX ................................................................................................................... 69
Appendix A: Physical Properties of Aggregate ........................................................ 69
Appendix B: Physical Properties of Bitumen ........................................................... 73
Appendix C: FTIR IR Spectrum Table by Frequency Range ................................... 74
Appendix D: Equations for Marshall and ITS test .................................................... 77
Appendix E: Marshall Mix Design Result for OBC Determination ......................... 79
Appendix F: Marshall Mix Design Result with Varying proportion of WPB .......... 82
Appendix G: ITS Test Results .................................................................................. 85
Appendix H: SPSS Software Outputs ....................................................................... 89
Appendix I: Photos ................................................................................................... 97
vii
LIST OF ABBREVIATIONS
AI Asphalt Institute
ANOVA Analysis of Variance
ASTM American Society of Testing Material
ARWE Amhara Road Works Enterprise
CCECC China Civil Engineering Construction Corporation
DSC Differential Scanning Calorimetry
EI Elongation Index
ERA Ethiopian Road Authorities
FACT Fines Aggregate Crushing Test
FI Flakiness Index
FTIR Fourier Transform-Infrared Spectroscopy
HDPE High-Density Polyethylene
HMA Hot Mix Asphalt
IFH International First Highway
ITS Indirect Tensile Strength
LAA Los Angeles Abrasion
LDPE Low-Density Polyethylene
NMAS Nominal Maximum Aggregate Size
NP Non-Plastic
OBC Optimum Bitumen Content
OWPB Optimum Waste Plastic Bag
PET Polyethylene Terephthalate
UNEP United Nations Environment Programme
Va Air Voids
VFA Voids Filled with Asphalt
VMA Voids in the Mineral Aggregates
WPB Waste Plastic Bag
viii
LIST OF FIGURES
Figure 1 Improper disposal of plastic waste ...................................................................... 4
Figure 2 Aggregate gradation; 9.5 mm NMAS ................................................................ 19
Figure 3 Aggregate gradation; 12.5 mm NMAS .............................................................. 19
Figure 4 Aggregate gradation; 19 mm NMAS ................................................................. 20
Figure 5 Aggregate gradation; for the three NMAS ......................................................... 21
Figure 6 Processed WPB .................................................................................................. 24
Figure 7 DSC Test Result ................................................................................................. 25
Figure 8 FTIR Test Result ................................................................................................ 26
Figure 9 OBC with varying NMAS .................................................................................. 32
Figure 10 Effect of WPB on Bulk density ........................................................................ 35
Figure 11 Effect of WPB on Flow .................................................................................... 37
Figure 12 Effect of WPB on Stability ............................................................................... 38
Figure 13 Effect of WPB on Air void ............................................................................... 40
Figure 14 Effect of WPB on VMA ................................................................................... 41
Figure 15 Effect of WPB on VFA .................................................................................... 42
Figure 16 OWPB content .................................................................................................. 43
Figure 17 TSR Test results ............................................................................................... 46
Figure 18 ITS Test results ................................................................................................. 48
ix
LIST OF TABLES
Table 1 Types of plastics, applications and SPI code ....................................................... 11
Table 2 Summary and result comparisons from literatures .............................................. 15
Table 3 Aggregate Test Results ........................................................................................ 17
Table 4 Bitumen Test Results ........................................................................................... 22
Table 5 Criteria for Asphalt Concrete Mix Deign (Ethiopian Road Authority, 2013) ..... 28
Table 6 Summary of Marshall Test Results at OBC......................................................... 33
Table 7 Summary of test results at the optimum WPB content ........................................ 45
Table 8 ANOVA Analysis on Tests of b/n subject’s effects ............................................ 50
Table 9 Post-hoc multiple comparison b/n %WPB .......................................................... 51
Table 10 Post-hoc multiple comparison b/n NMAS ......................................................... 53
1
CHAPTER ONE
1 INTRODUCTION
1.1 BACKGROUND
Hot Mix Asphalt (HMA) pavements are the most predominant pavement type in Ethiopia.
The government is also allocating huge amount of budget to construct and upgrade the
existing road networks nationwide. However, the increase in road traffic volume in
combination with an insufficient degree of maintenance has caused an accelerated and
continuous deterioration of the road networks in Ethiopia (Japan International Cooperation
Agency, 2013; Asphalt Institute, 2014). To alleviate this problem, several types of
measures may be effective, e.g., securing funds for maintenance, improved roadway
design, use of better quality of materials and the use of more effective construction
methods. The road network in Ethiopia has a primarily flexible pavement design. Several
factors influence the performance of flexible pavements, such as the properties of the
components (bitumen, aggregate and additive) and the proportion of these components in
the mix (Asphalt Institute, 2014).
Bitumen and asphalt concrete mixture can be modified by adding different types of
additive. One of these additives is the polymers. Polymer modified binders also show
improved adhesion and cohesion properties. Polymers can be also added to the asphalt
concrete mixtures to form an aggregate coating material. The coatings would enhance
surface roughness of the aggregates and thus, produce asphalt mixtures with superior
engineering properties (M.T.Awwad & L.Shbeeb, 2007).
Flexible pavement gives us an opportunity to use waste materials in it like plastic waste
after recycle. Using recycled plastic materials in road pavements is nowadays considered
not only as a positive option in terms of sustainability, but also, as an attractive option in
means of providing enhanced performance in service (Justo & Veeraragavan, 2002).
Due to rapid industrial growth together with population growth, an obvious increase in
waste generation rates for various types of waste materials is observed. Disposal of these
large amount of wastes especially non-decaying waste materials become a problem of great
2
concern in developed as well as in developing countries. Recycling waste into useful
products is considered to be one of the most sustainable solutions for this problem. So that,
research into new and innovative uses of waste materials is extensively encouraged (Justo
& Veeraragavan, 2002).
Plastic bags are mainly composed of Low-Density Polyethylene (LDPE) and it’s widely
used for packaging. However, disposal of waste plastic bags in large quantities has been a
problem as it’s not a biodegradable material. Several studies have been made on the
possible use of waste plastic bags and plastics in general in asphalt mix. Depending upon
their chemical composition and physical state, they have been employed as binder
modifiers or as aggregates coat as well as they can be used as elements which partially
substitute portion of aggregates in asphalt mix. Results were encouraging and exhibit an
improvement in performance of the modified asphalt mixes ( (Justo & Veeraragavan,
2002), (C.Giriftinoglu, 2007)).
Moisture damage in asphalt mixtures refers to loss in strength and durability due to the
presence of water. Many variables affect the amount of moisture damage which occurs in
an asphalt concrete mixture. Some of these are related to the materials forming hot mix
asphalt (HMA) such as aggregate and bitumen. Others are related to mixture design and
construction (air void level, film thickness, permeability, and drainage), environmental
factors (temperature, pavement age, freeze–thaw cycles, and presence of ions in the water),
traffic conditions and type, and properties of the additives. To alleviate the deformations
due to water damage, various researches were performed leading to the utilization of anti-
stripping additives. Anti-stripping additives are used to increase physico-chemical bond
between the bitumen and aggregate and to improve wetting by lowering the surface tension
of the bitumen (A.E.AbuEl-MaatyBehiry, 2013).
This study evaluates the effect of using waste plastic bags as an aggregate coating in asphalt
mixture. The Marshall and moisture susceptibility /water damage/ tests were used to
investigate the properties of mixtures in the laboratory.
Different mixtures were prepared by varying percentage WPB contents in accordance with
the Marshall Mix design procedure. Using the Marshall Mix design criteria for heavy
traffic loading, optimum asphalt content was selected. To investigate the moisture
3
susceptibility, for conditioned and unconditioned mixtures, additional test specimens were
prepared at, below and above optimum WPB contents.
1.2 STATEMENT OF THE PROBLEM
Due to the over increasing of traffic volumes and loading repetitions in combination with
an insufficient degree of maintenance, different types of surface distress has been observed
on most of the asphalt roads. The major distress are potholes, raveling of asphalt surface
and rutting due to overloading of the vehicles (M.T.Awwad & L.Shbeeb, 2007). One
solution to this crisis is recycling waste into useful products. Scientists and engineers are
constantly searching on different methods to improve the performance of asphalt
pavements.
Plastic is everywhere in today's lifestyle, it has numerous applications in various sectors
such as packaging, protecting, agriculture, construction and even disposing of all kinds of
consumer goods. In Bahir Dar city plastic constitutes 3.28% by weight of total municipal
waste per day (UNEP(b), Forum for Environment, 2010). Plastic bag waste generation in
Bahir Dar, the total of 24.87 ton of plastic bag waste is generated annually. This is
equivalent to more than 12 million plastic bags per year that enter into the environment as
the waste. In plastic waste stream, plastic bag waste constitutes a large proportion, which
accounts 92% by weight and 89.4% by volume. The plastic bag waste generation is
increased through times (Yehuala, 2007).
Plastic is non-biodegradable material which will remain in the environment for hundreds
of years leading to waste disposal crisis as well as various environmental concerns. In Bahir
Dar city about 27.6% the generated municipal solid wastes are either burned or buried in
their compound or disposed to lakesides or into the river (UNEP(a), Forum for
Environment, 2010). Therefore, the plastic wastes which is not dispose properly would
enters to the lake Tana and make it polluted. Hence there is a need for innovative and
sustainable approaches to use these growing quantities of plastic wastes.
After reviewing the previous studies related to utilization of plastics and plastics wastes in
the asphalt mix as a modifier, researchers understand that there are different types and
4
forms for addition of plastics to asphalt mix which can improve asphalt mix properties.
Properties of modified asphalt mix are related to many aspects such as plastic type,
utilization form and percentage of added plastic.
Figure 1 Improper disposal of plastic waste (Bahir Dar – Bezawit forest)
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Although studies have been made on the possible use of waste plastic bags and plastics in
general in asphalt mix, the effect of adding WPB on the asphalt mixtures with varying
nominal size of aggregate and how much percentage of bitumen can be replaced by waste
plastic bags with satisfying the local and international standard specifications are
questionable.
This study is conducted to evaluate the effect of using WPB as an aggregate coat on the
asphalt concrete mixtures under the local conditions in Bahir Dar.
1.3 OBJECTIVE OF THE STUDY
General objective
The aim of this research is to study the possibility of using WPB as an aggregate coat in
asphalt concrete mixtures.
Specific objectives
The specific objective of the study incudes: -
o To evaluate the effect of waste plastic bag replacement in asphalt concrete mix
using Marshall Mix design and Indirect Tensile strength test (i.e. moisture damage).
o To identify the optimum percentage of WPB replacement.
o To analyze the economic advantage of using WPB in the asphalt mixture.
1.4 SCOPE AND LIMITATION OF THE STUDY
This study had a set of limitations and criteria that were taken into account during the
experimental work. These limitations include:
o The research reported herein was focused on asphalt concrete characteristics such
as the Marshall properties, stripping effect of waste plastic bags in asphalt concrete.
Results produced in this research were based on Marshall Mix Design and Indirect
Tensile Strength (ITS) test.
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o The materials for this study were collected from the local (Bahr Dar), i.e. aggregate
and 60/70 bitumen from China Civil Engineering Construction Corporation
(CCECC) construction quarry and crusher site located around ‘Yibab’ and waste
plastic bags are from Ashraf industrial group plc (water and oil factory). All these
materials were tested and evaluated in the laboratory. The mixtures were prepared
by varying different percentage of waste plastic bags.
o Clean and processed waste plastic bags used for packaging the water and oil bottles
in Ashraf water and oil factory were used in this study and other types of waste
plastic bags are not within the concern of this research study.
o The size of processed waste plastic bags, which was used as an aggregate coat,
ranges from 2.36mm to 4.75 mm.
1.5 SIGNIFICANCE OF THE STUDY
o Using waste plastic bag as aggregate coat to improve the Marshall properties of
asphalt pavement.
o Reducing the amount of waste plastic materials and the area of land used for
landfill.
o Preservation of the environment by minimizing improperly disposed waste plastics.
o Creating employment opportunities.
o Reduction in maintenance and rehabilitation costs.
7
CHAPTER TWO
2 LITERATURE REVIEW
2.1 INTRODUCTION
Asphalt pavement is basically a mixture of natural raw materials: coarse and fine
aggregates, filler and bitumen. In addition to these standard materials from natural sources,
some additives may be incorporated to influence the performance of the product (Asphalt
Institute, 2014).
Asphalt pavement performance is affected by several factors, e.g., the properties of the
components (binder, aggregate and additive) and the proportion of these components in the
mix. The performance of asphalt mixtures can be improved with the utilization of various
types of additives, these additives include: polymers, latex, fibers and many chemical
additives (M.T.Awwad & L.Shbeeb, 2007).
It’s proven that the addition of certain polymer additive to asphalt mix can improve the
performance of road pavement. The addition of polymers typically exhibits improved
durability, greater resistance to permanent deformation in the form of rutting and thermal
cracking. Besides, it increases stiffness and decreased fatigue damage. Waste plastic bags
which is mainly composed of Low-Density Polyethylene (LDPE) has been found to be one
of the most effective polymer additives which would enhance the life of the road pavement
and also solve many environmental problems (Z.Kalantar, A.Mahrez, & M.R.Karim,
2010).
The research herein with concentrates and builds on the Marshal Properties and moisture
susceptibility of HMA mixtures prepared by adding different percentage of waste plastic
bag on asphalt concrete as an aggregate coating.
In this chapter, review of researches conducted on the effect of waste plastics on HMA
performance will be discussed.
8
2.2 HOT MIX ASPHALT CONCRETE
It is the most widely used paving material around the world. It's known by many different
names: HMA, asphaltic concrete, plant mix, bituminous mix, bituminous concrete, and
many others.
It is a combination of two primary ingredients aggregates and asphalt binder. Aggregates
include both coarse and fine materials, typically a combination of different size rock and
sand. In the asphalt concrete, aggregate typically makes up about 95% of a Hot Mix Asphalt
(HMA) mixture by weight, whereas asphalt binder makes up the remaining 5%. By
volume, a typical HMA mixture is about 85% aggregate, 10% asphalt binder, and 5% air
voids. Additives are added in small amounts to many HMA mixtures to enhance their
performance or workability. These additives include fibers, crumb rubber, and anti-strip
additives (Transportation research board committee, 2011).
Asphalt concrete pavements are not simply a thin covering of asphalt concrete over soil
they are engineered structures composed of several different layers. Because asphalt
concrete is much more flexible than Portland cement concrete, asphalt concrete pavements
are sometimes called flexible pavements. The visible part of an asphalt concrete pavement,
the part that directly supports truck and passenger vehicles, is called the surface course or
wearing course (Transportation research board committee, 2011).
Basic materials in hot mix asphalt
i. Aggregates
Aggregates (or mineral aggregates) are hard, inert materials such as sand, gravel, crushed
rock, slag, or rock dust. Properly selected and graded aggregates are mixed with the asphalt
binder to form HMA pavements. Aggregates are the principal load supporting components
of HMA pavement.
About 95% of the weight of dense graded HMA is made up of aggregates, HMA pavement
performance is greatly influenced by the characteristics of the aggregates. Aggregates in
HMA can be divided into three types according to their size: coarse aggregates, fine
aggregates, and mineral filler. Coarse aggregates are generally defined as those retained on
9
the 2.36mm sieve. Fine aggregates are those that pass through the 2.36mm sieve and are
retained on the 0.075mm sieve. Mineral filler is defined as that portion of the aggregate
passing the 0.075mm sieve. Mineral filler material also referred to as mineral dust or rock
dust consists of very fine, inert mineral with the consistency of flour, which is added to the
hot mix asphalt to improve the density and strength of the mixture. It shall be incorporated
as part of the combined aggregate gradation (Transportation research board committee,
2011).
Mineral aggregate properties play an important role in solving the problem of permanent
deformation. Fatigue cracking and low-temperature cracking are less affected by aggregate
characteristics. Therefore, it is important to thoroughly understand the impacts of aggregate
gradation (Asphalt Institute, 2014).
ii. Asphalt binder (bitumen)
Asphalt binder (bitumen) which holds aggregates together in HMA is thick, heavy residue
remaining after refining crude oil. Asphalt binder consists mostly of carbon and hydrogen,
with small amounts of oxygen, sulfur, and several metals. The physical properties of
asphalt binder vary considerably with temperature. At high temperatures, asphalt binder is
a fluid with a low consistency similar to that of oil. At room temperature most asphalt
binders will have the consistency of soft rubber. At subzero temperatures, asphalt binder
can become very brittle. Many asphalt binders contain small percentages of polymer to
improve their physical properties; these materials are called polymer modified binders.
Most of asphalt binder specification was designed to control changes in consistency with
temperature (Transportation research board committee, 2011).
2.3 MOISTURE SUSCEPIBILITY OF HOT MIX ASPHALT
The presence of water in an asphalt pavement is unavoidable. Several sources can lead to
the presence of water in the pavement. Water can infiltrate the pavement from the surface
via cracks in the surface of the pavement, via the interconnectivity of the air-void system
or cracks, from the bottom due to an increase in the ground water level, or from the sides.
The presence of moisture, combined with the repeated action of traffic, accelerates damage
to the asphalt pavement (L.Santucci, 2002).
10
Moisture damage can be defined as the loss of strength and durability in asphalt mixtures
due to the effects of moisture (D.N.Little & D.R.Jones, 2003). Premature failure may result
due to stripping when critical environmental conditions act together with poor and/or
incompatible materials and traffic. Moisture susceptibility is a problem that typically leads
to the stripping of the asphalt binder from the aggregate, and this stripping makes an asphalt
concrete mixture ravel and disintegrate. Moisture damage can occur due to three main
mechanisms: loss of cohesion of the asphalt film, failure of the adhesion between the
aggregate particles and the asphalt film, and degradation of aggregate particles due to
freezing (E.R.Brown, P.S.Kandhal, & J.Zhang, 2001).
Moisture can damage HMA by loss of bond between asphalt cement or mastic and fine and
coarse aggregate or by weakening of mastic due to the presence of moisture. Therefore, a
need exists to examine the adhesive interface between aggregates and asphalt and the
cohesive strength and durability of mastics (F.L.Roberts, 1996). A loss of the adhesive
bond between aggregate and asphalt can lead to stripping and raveling, while a loss of
cohesion can lead to a weakened pavement that is susceptible to premature cracking and
pore pressure damage (K.Majidzadeh & F.N.Brovold, 1968).
2.4 PLASTIC POLYMERS
Plastics are mainly organic polymers of high molecular mass. The raw materials for plastics
production are natural products such as cellulose, coal, natural gas, salt and crude oil.
Different plastics have different polymer chain structures which determine many of their
physical characteristics. The vast majority of these polymers are based on chains of carbon
atoms alone or with oxygen, sulfur, or nitrogen as well (C.Giriftinoglu, 2007).
2.4.1 Types of plastics
The Society of the Plastics Industry (SPI) established a special numbered coding system in
1988 to allow consumers and recyclers to properly identify the type of resin that was used in
manufacturing a product. Manufacturers follow a coding system and place an SPI code, or
number, on each plastic product, which is usually molded into the bottom. Table 1
11
illustrates the most common types of plastics used, their applications and SPI code
(C.Giriftinoglu, 2007).
Table 1 Types of plastics, applications and SPI code
Plastic type Abbrev. Examples of applications SPI
Polyethylene
Terephthalate PET Soft drink and water bottles.
High Density
Polyethylene HDPE
Cleaners and shampoo bottles, molded
plastic cases.
Polyvinyl
Chloride
PVC or
V
Pipes, fittings, credit cards, toys,
electrical fittings, pens; medical
disposables; etc.
Low Density
Polyethylene LDPE Grocery bags and packaging films.
Polypropylene PP
Bottle caps and closures, diapers,
microwaveable meal trays, medicine and
syrup bottles, also produced as fibers and
filaments for carpets.
Polystyrene PS
Styrofoam, Take-away food containers,
egg cartons, disposable cups, plastic
cutlery, CD and cassette boxes.
Other types of
plastics OTHER
Any other plastics that do not fall into
any of the above categories, for example
polycarbonate which is
Compact discs, eyeglasses, riot shields,
security windows.
12
Low Density Polyethylene (LDPE)
Density Polyethylene (LDPE) has a widely usage especially in dispensing bottles or wash
bottles, general purpose tubing, bags and small tanks. Chemically LDPE is uncreative at
room temperature although it is slowly attacked by strong oxidizing agents and some
solvents will cause softening or swelling. It may be used at temperatures up to 95°C for
short periods and at 80°C continuously (C.Giriftinoglu, 2007).
General Properties of LDPE (M.T.Awwad & L.Shbeeb, 2007)
o Tough;
o Flexible;
o Good moisture barrier properties.
o Density (g/cm3): 0.92
o Approx. melting point (°C): 110
o Water Absorption, 24 hrs. (%): <0.01
o Tensile Strength (psi): 1,800 – 2,200
2.5 LABORATORY STUDIES ON UTILIZATION OF PLASTICS IN HMA
Several investigations have been carried out on incorporating polymers to improve
performance of asphalt mixtures. Recycled plastics is one of polymers can replace a portion
of aggregates, use as a binder modifier or as an aggregates coating material.
i. Plastics for binder modification
The processed plastic bags were used as an additive with heated bitumen in different
proportions (ranging from 0 to 12 % by weight of bitumen) and mixed well to obtain the
modified bitumen. Laboratory investigations have given highly encouraging results for the
use of modified bitumen, and show the addition of processed plastic, about 8.0 % by weight
of bitumen, helps in substantially improving the stability or strength, fatigue life and other
desirable properties of asphalt concrete mix, even under adverse water-logging conditions.
Therefore, the life of the pavement surfacing course using the modified bitumen is also
expected to increase substantially in comparison to the use of ordinary bitumen. Besides,
the addition of 8.0 % processed plastic by weight of bitumen for the preparation of modified
13
bitumen results in a saving of 0.4 % bitumen by weight of the mix that would contribute in
reducing the overall cost of asphalt mix (Justo & Veeraragavan, 2002).
Waste PET as polymer additives for binder in asphalt mix were also studied by make it
powdered and mixed in proportions 2, 4, 6, 8 and 10 % (by the weight of OBC) with
bitumen at temperature 150 oC. PET modified binder resulted in higher resistance to
permanent deformation and higher resistance to rutting due to their higher softening point
when compared to conventional binders. Decrease in consistency and increase in the
resistance to flow and temperature changes also appears in PET modified binder
(Z.Kalantar, A.Mahrez, & M.R.Karim, 2010).
ii. Plastics as an aggregate coat
Partial replacement of waste plastic (Polyethylene Terephthalate (PET)) with different
percentages of waste plastic by weight of asphalt binder (6%, 9%, 12% and 15%) improves
the Marshall Stability and flow of binders at high temperature ranges and has a little effect
on the HMA mixture. Study indicates that, it is feasible to partially replace asphalt binder
with waste plastic up to 12% of OBC by weight (Engidaeshet, 2018).
To enhance asphalt mixture properties, two types of polyethylene as a polymer in two states
were added to coat mix aggregates (Grinded and not grinded Low-Density Polyethylene
(LDPE) and High-Density Polyethylene (HDPE)). Marshal mix design procedures were
used to determine Optimum Bitumen Content (OBC), then seven proportions of
polyethylene of each type and state by weight of OBC were selected to be tested (6, 8, 10,
12, 14, 16 and 18%). The tests include the determination of bulk density, stability and flow.
Results indicated that 12% of grinded HDPE polyethylene modifier provides better
engineering properties. It is found to increase the stability, reduce the density and slightly
increase the air voids (M.T.Awwad & L.Shbeeb, 2007).
Conventional properties of bituminous mixes were compared with mix containing
plastic/polymer (PP) (8% and 15% by weight of bitumen). Waste PP modifier was used in
a shredded form (Particle size, diam. 2-3 mm), graded aggregates were heated at 150-1600C
in oven and waste PP modifier was added into hot aggregates before mixing with OBC.
14
Marshall Specimens for conventional and modified mixes were tested and evaluated.
Results show that marshal stability of modified mixes was 1.21 and 1.18 times higher than
conventional mixes, for modifier proportions 8 and 15% respectively. ITS and rutting
resistance were also improved in modified mixes. Indirect Tensile Strength (ITS) for
conventional mix was 6.42 kg/cm2 while these where 10.7 and 8.2 kg/cm2 for modified
mixes 8 and 15% respectively, rutting for conventional mix was 7 mm for modified mixes
8 and 15% are 2.7mm and 3.7mm respectively). Thus, waste PP modified bituminous
mixes are expected to be more durable and have an improved performance in field
conditions (Sabina, Khan, Sangita, Sharma, & Sharma, 2009).
iii. Plastics to replace portion of aggregates
Recycled plastics mainly composed of LDPE in pellet form were used to replace (by
volume) a portion of the mineral aggregates of an equal size (2.36–5.0 mm), producing
new mix named (Plastiphalt). Results indicated that 30% aggregate replacement by volume
with recycled plastic pellets reduce bulk density by 16% and show much higher Marshal
stability, approximately 2.5 times that of control mix. Recorded flow values were also
higher indicating that Plastiphalt mixes are both stronger and more elastic. Besides, the ITS
value was found to be higher in Plastiphalt mix. Overall, the mechanical properties of aged
recycled Plastiphalt mixes are superior to those of control mixes composed of mineral
aggregates (Suparma & Zoorob, 2000).
2.6 SUMMARY
From the literature review, different types of plastics and waste plastics were used in
asphalt mix as a bitumen modifier, as an aggregate coating and as replacing potion of
aggregate (Plastiphalt) in different countries, but it is not common in Ethiopia. Researchers
also indicate the advantage of plastic modified asphalt mix on the mechanical properties of
asphalt mixtures. Results from different studies are compared and summarized on Table 2.
Therefore, this research studied the uses of waste plastic bags (WPB) as an aggregate coat
in asphalt mixtures with varying NMAS.
15
Table 2 Summary and result comparisons from literatures
Authors Variable Findings / Results Remark
Z.Kalantar,
A.Mahrez and
M.R.Karim,
(2010)
Waste PET in
proportions 2, 4, 6, 8
and 10 % (by the
weight of OBC)
PET modified binder resulted in
higher resistance to rutting due to
their higher softening point when
compared to conventional binders.
Plastics for
binder
modification C. Justo and A.
Veeraragavan,
(2002)
Processed plastic bags
in different
proportions (ranging
from 0 to 12 % by
weight of bitumen)
8.0 % by weight of bitumen, helps in
substantially improving the stability,
fatigue life and other desirable
properties of asphalt concrete mix,
even under adverse water-logging
conditions and a saving of 0.4 %
bitumen by weight of the mix.
Engidaeshet,
Befekadu,
(2018)
PET with different
percentages of waste
plastic by weight of
asphalt binder (6, 9, 12
and 15%)
Improves Stability and flow of
binders at high temperature ranges
and has a little effect on the HMA
mixture. Partially replace asphalt
binder with waste plastic up to 12%
of OBC by weight is feasible. Plastics as
an aggregate
coat
M.T.Awwad
and L.Shbeeb,
(2007)
Grinded and not
grinded LDPE and
HDPE with
proportions 6, 8, 10,
12, 14, 16 and 18%.
Results indicated that 12% of
grinded HDPE polyethylene
modifier provides better engineering
properties.
S. Suparma
and L. Zoorob,
(2000)
LDPE in pellet form
were used to replace
(by volume) a portion
of the mineral
aggregates of an equal
size (2.36–5.0 mm)
(Plastiphalt).
Results indicated that 30% aggregate
replacement by volume with
recycled plastic pellets reduce bulk
density by 16% and show much
higher stability, approximately 2.5
times that of control mix.
Plastics to
replace
portion of
aggregates
16
CHAPTER THREE
3 METHODS AND MATERIALS
3.1 INTRODUCTION
The study focused on investigating the Marshall properties and moisture susceptibility of
bituminous mixture prepared in the laboratory by using waste plastic bags as an aggregate
coat ranging from 0 - 18% by weight of the optimum bitumen content.
This study involves on collecting of raw materials for the preparation of bituminous
mixtures. The materials used in the mixture includes: coarse and fine aggregates, mineral
fillers, waste plastic bags and asphalt binder.
The crushed stone coarse aggregates, fine aggregates and mineral fillers are collected from
CCECC construction quarry and crusher site located at ‘Yibab’. Waste plastic bag was
collected and grinded at Ashraf water and oil factory. The asphalt cement of 60/70
penetration grade was also obtained from CCECC batching plant.
These ingredient materials were subjected to various laboratory tests in order to determine
their physical properties whether they can meet common specification limits. These quality
assurance tests conducted on the aggregates include: gradation, Los Angeles abrasion,
flakiness index, aggregate crushing value, specific gravity, plastic index, linear shrinkage,
ten percent finesse value and water absorption tests. The tests carried out on the asphalt
cement sample include: specific gravity, ductility, flash point, penetration, softening point,
loss on heating, residue penetration and residue ductility.
According to Marshall Mix Design procedure and criteria different mixture properties were
obtained and the optimum asphalt binder content was determined. Test specimens were
then prepared using different amount of waste plastic bag as an aggregate coat by weight
of optimum asphalt content in the mix.
To end, mixtures were prepared using different percentage of waste plastic bags at their
respective optimum asphalt binder content to investigate the mixture resistance to moisture
damages using Indirect Tensile Strength /ITS/ test.
17
3.2 MATERIALS CHARACTERISTICS
3.2.1 Aggregate
Physical characteristics of mineral aggregates and its suitability for road construction were
evaluated. Since around Bahir Dar basalt rocks are available in large quantities, in this
study basalt type of aggregates were used. Table 3 shows the physical properties of mineral
aggregates.
Plasticity Index and Linear shrinkage tests were conducted for material passing 0.425mm
sieve which is used to check the cleanliness properties of aggregates especially the fine
aggregate materials. Aggregates must be relatively clean when used in HMA. Vegetation,
soft particles, clay lumps, excess dust and vegetable matter are not desirable because they
generally affect performance by quickly degrading, which causes a loss of structural
support and/or prevents binder-aggregate bonding. As shown from Table 3, the test result
of Plasticity Index and Linear shrinkage are NP and 1.8% respectively. Therefore, the result
shows that the materials are suitable of HMA pavement constructions and satisfied the
ERA requirements.
Table 3 Aggregate Test Results
No Test Description Test Method
Test
Result
(Mean)
Standard
Deviation
Specification
Requirements
(ERA, 2013)
1 Plasticity Index % BS 1377: Part 2 NP - < 4
2 Linear shrinkage % BS 1377: Part 2 1.8 0.04 < 2
3 Flakiness Index % BS 812, Part 105 26 1 < 35
4 Aggregate Crushing Value % BS 812, Part 3 9 0.25 < 25
5 Aggregate Impact Value % BS 812, Part 3 7 0.21 < 25
6 10% FACT (dry) kN BS 812, Part 3 490 2.69 >160
7 Los Angeles Abrasion % ASTM C131 12 - < 30
8 Water absorption % BS 812, Part 2 1.6 - <2
18
Flakiness Index test were conducted for aggregate particles of size from a range of 6.3mm
to 63mm, to determine the particle shape properties. Aggregate particle shape and surface
texture are important for proper compaction, deformation resistance, and workability. In
HMA, since aggregates are relied upon to provide stiffness and strength by interlocking
with one another, cubic angular-shaped particles with a rough surface texture are best.
Rounded particles create less particle-to-particle interlock than angular particles and thus
provide better workability and easier compaction. However, in HMA less interlock is
generally a disadvantage as rounded aggregate will continue to compact, shove and rut
after construction. In the other way, flaky and elongated aggregate particles tend to impede
compaction or break during compaction and thus, may decrease strength. From the test
result, the aggregate has Flakiness Index of 26%. The result satisfied minimum ERA
standard specification’s and are suitable of HMA.
Aggregate Crushing Value, Aggregate Impact Value, 10% Fines Aggregate Crushing Test
(10% FACT) and Los Angeles Abrasion tests were used to determine the strength,
toughness and abrasion characteristics properties of aggregate particles. Aggregates
undergo substantial wear and tear throughout their life. In general, they should be hard and
tough enough to resist crushing, degradation and disintegration from any associated
activities including manufacturing, stockpiling, production, placing and compaction.
Furthermore, they must be able to adequately transmit loads from the pavement surface to
the underlying layers (and eventually the subgrade). Aggregates not adequately resistant to
abrasion will cause premature structural failure and/or a loss of skid resistance. From Table
3, the test results of Aggregate Crushing Value, Aggregate Impact Value, 10% FACT and
Los Angeles Abrasion are 9%, 7%, 490kN and 12% respectively. Test results satisfied the
minimum ERA standard specifications.
Water absorption test was conducted to check the absorption capacity of the aggregate
particles. It is generally desirable to avoid highly absorptive aggregate in HMA. This is
because asphalt binder that is absorbed by the aggregate decrease the amount of binder to
coat the aggregate particle surface and reduce bonding. Therefore, highly absorptive
aggregates require more asphalt binder to develop the same film thickness as less
absorptive aggregates making the resulting HMA more expensive. From the test result, the
19
aggregate has a water absorption capacity of 1.6%, which is marginally accepted based on
ERA standard specifications.
Figure 2 Aggregate gradation; 9.5 mm NMAS
Figure 3 Aggregate gradation; 12.5 mm NMAS
0
20
40
60
80
100P
erc
en
t p
assin
g (
%)
Sieve size (mm) raised to 0.45 power
0.075 0.3 2.36 4.75 9.5 12.5 19.0 25.0 37.5
Mix
Lower
Upper
Maximum density line
0
20
40
60
80
100
Perc
en
t p
assin
g (
%)
Sieve size (mm) raised to 0.45 power
0.075 0.3 2.36 4.75 9.5 12.5 19.0 25.0 37.5
Mix
Lower
Upper
Maximum density line
20
Figure 4 Aggregate gradation; 19 mm NMAS
Figure 2,3,4 shows the final proportion of each of the three nominal maximum aggregate
size. Gradation of an aggregate is one of the most influential aggregate characteristics in
determining how it will perform as a pavement material. In HMA, gradation helps
determine almost every important property including stiffness, stability, durability,
permeability, workability, fatigue resistance, frictional resistance and moisture
susceptibility (F.L.Roberts, 1996). To produce well and controlled gradation, aggregates
were first sieved and recombined in the laboratory to produce the mineral aggregate that
can meet the selected gradation based on ERA 2013 wearing course specifications. The
coarse and fine aggregate particles were first separated into different sieve size and
proportioned to obtain the desired gradation for nominal maximum aggregate size of 9.5,
12.5 and 9mm. Figure 5 shows the gradation curves plotted together for the three NMAS
types. From this figure it is possible to compare the percentage passing easily for all
NMAS.
0
20
40
60
80
100
Perc
en
t p
assin
g (
%)
Sieve size (mm) raised to 0.45 power
0.075 0.3 2.36 4.75 9.5 12.5 19.0 25.0 37.5
Mix
Lower
Upper
Maximim density line
21
Figure 5 Aggregate gradation; for the three NMAS
3.2.2 Asphalt Binder
Asphalt binder 60/70 penetration from Iran was used in this research since currently most
road projects around Bahir Dar were uses this type of bitumen. The laboratory tests
performed to evaluate the bitumen properties were: specific gravity, ductility, flash point,
penetration, softening point, loss on heating, residue penetration and residue ductility. The
properties of asphalt binder, which are presented in Table 4, are within the specification of
asphalt grade 60/70.
0
20
40
60
80
100
Perc
en
t p
assin
g (
%)
Sieve size (mm) raised to 0.45 power
0.075 0.3 2.36 4.75 9.5 12.5 19.0 25.0 37.5
9.5mm
12.5mm
19mm
22
Table 4 Bitumen Test Results
No Test Description Test Method
Test
Result
(Mean)
Standard
Deviation
Specification
Requirements
(ERA, 2013)
1 Specific Gravity at 25oC
(g/cm³） AASHTO T 228 1.019 0.004 -
2 Penetration at 25oC,100g, 5
sec. (mm) AASHTO T 49 62 1.63 60 - 70
3 Ductility at 25oC/(cm) AASHTO T 51 100+ 3.27 Min. 100
4 Softening Point (oC) ASTM D 36 48 2.16 46 - 56
5 Flash Point (oC) AASHTO T 48 283 8.04 Min. 232
6 Loss on Heating (oC), 5h at
163oC (%) AASHTO T 47 0.2 0.12 Max. 0.5
7 Residue Penetration (% of
original) AASHTO T 49 55 1.63 Min. 54
8 Residue Ductility at
25oC/(cm) ASTM D 113 81 3.09 Min. 50
Specific gravity of asphalt binder was conducted at 25oC and it is a fundamental property
that frequently required. In case bitumen contains mineral impurities, the specific gravity
will be higher. Thus, it is possible for a quantitative extraction of impurity in bitumen. It is
also important to convert bitumen weights into volumes for asphalt concrete mix design.
Penetration test was also conducted at 25oC, it is used to measure the consistency of
bitumen, so that it can be classified a given bitumen into standard grades. Greater value of
penetration indicates softer consistency. Generally higher penetration bitumen is preferred
for use in cold climate and smaller penetration bitumen is used in hot climate areas. From
the test results, a bitumen used for this research was classified as 60/70 grade.
Ductility is defined as the distance in cm, to which a standard sample or briquette of the
material will be elongated without breaking. This test provides measure of tensile
properties of bituminous materials and may be used to measure ductility for specification
requirements. Bituminous materials used in pavement construction should possess
sufficient ductility otherwise the pavement would crack due to temperature or traffic
stresses and may damage the pavement structure.
23
The softening point is defined as the temperature at which a bitumen sample can no longer
support the weight of a 3.5gram steel ball. Higher softening point ensures that they will not
flow during service. Higher the softening point, lesser the temperature susceptibility.
Bitumen with higher softening point is preferred in warmer places and vice versa.
Flash point of bitumen is the temperature at which, it's vapor will ignite temporarily during
heating, when a small flame is brought into contact with the vapor. The knowledge of this
point is of interest mainly to the user, since the bitumen must not be heated to this point. It
used to check the fire susceptibility of the bitumen. Lower the flash point, greater the fire
hazard.
In loss on heating test, a fifty-gram sample of bitumen in a film approximately 5 mm deep
is heated in moving air for five hours at 163°C and the loss in weight is determined. The
loss on heating test controls the volatility of a bitumen. In addition, it was an early attempt
to simulate the change in properties of a bitumen in an asphalt plant. The bitumen samples
after loss on heating, residue penetration and residue ductility tests were conducted.
As shown on Table 4, all bitumen test results satisfied the minimum ERA standard
specifications.
24
3.2.3 Waste Plastic Bags
The properties of waste plastic bag were described using DSC and FTIR tests as shown in
Figure 7 and Figure 8 respectively. Waste plastic bags were collected from Ashraf
industrial group plc (water and oil factory) and processed with a range between 2.36 mm
and 4.75 mm size by using grinding machine.
Figure 6 Processed WPB
Differential Scanning Calorimetry (DSC): - is a technique used to investigate the
response of polymers to heating. From DSC test result, plastic bags are categorized under
LDPE plastic material. DSC can be used to study the melting of a crystalline polymer or
the glass transition. From Figure 7 the melting point of WPB determined from DSC test
is114.8 oC. Based on the result this WPB melts before the mixing temperature since the
melting temperature is low. This is important for the better coating of the aggregate by
WPB.
25
Figure 7 DSC Test Result
Fourier Transform-Infrared Spectroscopy (FTIR): - is an analytical technique used to
identify organic (and in some cases inorganic) materials. This technique measures the
absorption of infrared radiation by the sample material versus wavelength. Absorbance (A)
plotted in the Y axis is used to measure the amount of IR radiation absorbed by a sample.
The infrared absorption bands identify molecular components and structures. Functional
groups of the organic and inorganic materials can be determined by using FTIR. IR
Spectroscopy measures the vibrations of atoms, and based on this it is possible to determine
the functional groups. Generally, stronger bonds and light atoms will vibrate at a high
stretching frequency (wavenumber). The wavenumber is the number of waves in one
centimeter and has the units of reciprocal centimeters (cm-1). Since the wavenumber is
inversely proportional to wavelength, it is directly proportional to frequency and energy
which makes it more convenient to use.
Therefore, WPB functional group / molecular components are identified using FTIR
equipment’s. From the test result as shown on Figure 8, this waste plastic material has
molecular components of (C-H) – bending, (CH3) – bending, (CH3) – stretching and (OH)-
290
300
310
320
330
340
350
360
0 100 200 300 400
Heat
Flo
w E
nd
o D
ow
n (
mW
)
Temperature (oC)
Lower Peak = 114.8 oC
26
bending. But on polyethylene materials (OH)-bending is not expected, this is may be due
to some vegetable matters or proteins. From literatures, asphalt binders mostly consist of
carbon and hydrogen, with small amount of oxygen, sulfur and several metals. This WPB
also has more or less comparative molecular components as bitumen. This helps to have
an affinity (i.e. an attraction force between particles that causes to combine) between
asphalt binder and WPB.
Figure 8 FTIR Test Result
3.3 EXPERIMENTAL WORK
An extensive experimental work was conducted to investigate the properties of asphalt mix
containing waste plastic bag and to find out the suitability of using this waste plastic bag
in asphalt mixtures.
After evaluating the properties of used materials like bitumen, aggregates, and waste plastic
bags, blending of aggregate were carrying out to fulfil the required gradation for wearing
course layer based on ERA 2013 flexible pavement design manual.
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
0.016
0.018
0.020
0.022
0.024
0.026
0.028
0.030
0 500 1000 1500 2000 2500 3000 3500 4000 4500
Ab
so
rba
nc
e,
A
Wavenumber (cm-1)
(C-H) -bending
(CH3) -bending
(CH3) -stretching
(CH3) -stretching
(O-H) -bending
27
Next, with different percentages of bitumen contents asphalt mixes were prepared to obtain
the optimum bitumen content by Marshall mix design test. Then, another asphalt mix were
prepared with bitumen content plus their respective waste plastic bag ratio. The ratio of
waste plastic bags added in the asphalt mix were (6, 9, 12, 15, and 18%) by the weight of
optimum bitumen content for the three (9.5, 12.5 & 19mm) NMAS.
Marshall Mix design and Indirect Tensile Strength (ITS) tests were used to evaluate the
asphalt mixtures. Finally, laboratory tests results were obtained and analyzed.
3.3.1 Marshall Hot Mix Design
Marshall Mix Design method was used to determine the optimum asphalt content and
evaluate the stability, flow and voids (Va, VMA & VFA) of the mix in the laboratory.
Fundamentally, mix design is meant to determine the volume of asphalt binder and
aggregates necessary to produce a mixture with the desired properties (F.L.Roberts, 1996).
An aggregate weighing about 1200gram were heated to a temperature of 165°C and 60/70
grade asphalt were mixed to a maximum temperature of 170°C.
Waste plastic bags with different percent of replacement rate from 6 - 18% of optimum
bitumen content with 3% increment was used with three replicates for each percentage.
First, the aggregate was hot then waste plastic bags were added and mixed together to coat
the aggregate before mixing OBC in dry process, then bitumen was added at a temperature
of 1400C. The mixture was then placed in the preheated mold and compacted using 75
blows on each sides of the specimen. After compaction, the specimen was allowed to cool
for 24 hours and removed from the mold by an extrusion jack. In accordance with the
Marshall procedure, each compacted test specimens were subjected to determination of
unit weight, void analysis, stability and flow tests. Then, plots were made to determine
values of each respective specimen prepared using different waste plastic bag replacement
rate. The formulas or equations used to calculate the Marshall properties are attached on
appendix C.
Determination of Optimum Bitumen Content
Five percentages of bitumen were examined to determine the best percentage of bitumen
28
content for the aggregates used, which include 4, 4.5, 5, 5.5 and 6% by weight of the mix
with three replicates for each percentage.
The procedure for determining optimum bitumen content for a particular mix under
evaluation was adopted from the publication by the Asphalt Institute (Asphalt Institute,
2014), where both ASTM D1559 and AASHTO R-12 standardized it. Plots were made for
each specimen prepared using different percentage of bitumen content. Accordingly, the
optimum bitumen content is obtained from the plotted graph initially with 4% of air voids.
Thus, all the calculated and measured mix properties are compared with acceptability
criteria given in Table 5 for heavy category and design traffic. Similarly, the Marshal
properties of individual mixes, prepared varying NMAS (9.5, 12.5 & 19mm) and (6, 9, 12
,15 &18) percentage of waste plastic bag replacement by weight of optimum bitumen
content was evaluated and will be discussed in chapter 4.
Generally, for Marshal stability test a total of 99 specimens were prepared [3 number of
nominal sizes of aggregate (15 specimens for determination of OBC + 18 specimens
prepared by varying percentage of waste plastic bags)].
Table 5 Criteria for Asphalt Concrete Mix Deign (Ethiopian Road Authority, 2013)
Marshall Method Mix Criteria
Category and design traffic
(106 ESA)
Heavy
(1 – 5)
Medium
(0.4 – 1)
Light
(< 0.4)
No. of blows of Marshall compaction hammer 75 50 35
Min. Stability (N) 8000 5300 3300
Flow (mm) 2 – 3.5 2 – 4 2 – 4.5
Void Filled with Asphalt, VFA (%) 65 – 75 65 – 78 70 – 80
Air void at optimum bitumen content (%) 3 - 5 3 - 5 3 - 5
Void in Mineral Aggregate, VMA (%)
≥13 for 19 mm
≥14 for 12.5 mm
≥15 for 9.5 mm
29
3.3.2 Moisture Sensitivity of the Mix
There are a number of methods for evaluating the moisture sensitivity of a mix. The most
common test procedures for evaluating the moisture sensitivity of an asphalt mixture are
the indirect tensile test procedures, AASHTO T 283 and ASTM D4867.
Indirect Tensile Strength Test
In these tests, a minimum of six test specimens were compacted to a target percentage of
air voids intended to simulate the expected in-place percentage of 6 – 8% air voids. The
compacted specimens were then separated into two subsets, a conditioned subset and an
unconditioned, or control, subset. It was assured that the two sets were equivalent in
properties and that the range of air void contents within each set was kept to a minimum
(typically plus/minus 0.2%).
According to AASHTO T 283, two subsets of six compacted specimens were used for each
nominal maximum size of aggregate and waste plastic bag content. One subset was a dry
subset where the specimen was wrapped with plastic and placed in a 25oC water bath for a
minimum of 2hr. The other subset was preconditioned where the specimens were placed
in the vacuum container having distilled water and applying a vacuum of 13 – 67kPa
absolute pressure (10 – 26 in. Hg partial pressure) for 5 – 10 minutes, the specimen was
removed from the vacuum and was submerged in water for 5 – 10 minutes. Then, degree
of saturation was determined by comparing volume of absorbed water with volume of air
voids. This volume of water was controlled to be between 55 and 80 percent of the volume
of air. Next the specimen was placed in water bath at 60oC plus/minus 1 for 24hr. After 24
plus/minus 1hr the specimen was removed and placed in water bath at 25 plus/minus 0.5
oC for 2 plus/minus 1hr and then prepared for indirect tensile strength test.
For indirect tensile strength test a total of 72 specimens were prepared [3 number of
nominal sizes of aggregate (6 specimens for control + 18 specimens prepared with varying
percentage of waste plastic bags starting from the optimum, below and above the
optimum)].
30
Tensile Strength Ratio
TSR express the numerical index or resistance of asphalt mixtures to the detrimental effect
of water as the ratio of the original strength that is retained after conditioning. The results
achieved from investigations conducted on all bituminous mixtures prepared using
different waste plastic bag content as described on previous sections were evaluated.
The following formulas or equations are used to calculate for both tensile strength and
tensile strength ratio.
i. The Tensile Strength, St
tD
PSt
2000=
where: P = maximum load, N
t = Specimen thickness, mm
D = Specimen diameter, mm
ii. Tensile Strength Ratio, TSR
100*(%),1
2
S
STSR =
where: 1S = average tensile strength of dry subset, and
2S = average tensile strength of conditioned subset
31
CHAPTER FOUR
4 RESULT AND DISCUSSION
Data analysis and results of laboratory tests conducted to evaluate the effect of partial
replacement of binder/bitumen by waste plastic bags in asphalt mixes and influence of
WPB content on the bulk density, stability, flow, air voids, VMA and VFA on the three
nominal maximum aggregate size (9.5, 12.5 &19mm) of asphalt concrete will be presented
in this chapter. Marshall Method for designing hot mix asphalt was used to determine both
the optimum bitumen content to be added to specific aggregate blend, and to evaluate and
determine the optimum WPB content in asphalt mix. The results of this study only apply
to the specific grinded size of WPB, which ranges from 2.36mm to 4.75mm and other size
of WPB may produce different results. Indirect Tensile Strength test was used to evaluate
the indirect tensile strength and moisture damage/ moisture susceptibility of the asphalt
mixes.
4.1 OPTIMUM BITUMEN CONTENT DETERMINATION
The results of Marshal tests on bituminous mixes were prepared at various bitumen
contents by total weight of mix. From the test results, 5.9, 5.5 and 4.9 % of optimum
bitumen content was determined for nominal maximum aggregate size of 9.5, 12.5 &
19mm respectively. The discussion is made taking the general trend of the curves. But on
some diagrams, there are some irregularities which occur due to laboratory work
limitations like difficulty to have consistent mixing temperature and minor aggregate loss
at the time of mechanical mixing.
Using Marshall Hot Mix Design procedures and ERA 2013 standard specification,
Marshall specimens were prepared for 9.5, 12.5 and 19mm NMAS. Optimum bitumen
content was selected at the air void content of 4.2, 4.2 and 4% respectively. With this air
void, as shown on Table 6 the mix can satisfy all the other requirements mentioned on local
(ERA) and international standard specifications. Therefore, the optimum bitumen content
32
determined from Marshall hot mix design for NMAS of 9.5, 12.5 and 19 mm was 5.9, 5.5
and 4.9% respectively.
The properties of mixtures at their various bitumen content for mixes with different
nominal maximum size of aggregate were plotted and attached at the appendix section of
this document (Appendix E).
Figure 9 OBC with varying NMAS
As shown on Figure 9 the optimum binder/bitumen content decreases through increasing
the NMAS. Firstly, decreasing the nominal aggregate size will increase the surface area of
the aggregate. Due to this large amount of bitumen is required to coat the whole surface
area of aggregate. Secondly, aggregate can resist majority of the imposed load. When the
aggregate size is large it can resist the load by itself than the smaller size of the aggregate.
Therefore, the aggregate having smaller size needs a lot of binder to resist the incoming
load. Due to the above reasons the binder content could decreases with increasing the
nominal aggregate sizes of the aggregate.
4
4.5
5
5.5
6
9.5 12.5 19
OB
C (
%)
NMAS (mm)
33
Table 6 below summarizes the Marshall Mix Design results for all NMAS types at their
optimum bitumen content. The table shows that in each NMAS types, all test results
fulfilled the required specifications.
Table 6 Summary of Marshall Test Results at OBC
NMAS
(mm)
Air
Void
(%)
VMA (%) VFA
(%)
Stability
(KN)
Flow
(mm)
Bulk
Density
(g/cm³)
OBC
(%)
9.5 4 16.2 67 8 3.4 2.364 5.9
12.5 4 14.4 72 9.9 3.3 2.395 5.5
19 4.2 13.1 67 9 3.4 2.412 4.9
Standard
Specification
(ERA 2013)
3 - 5
≥13 for 19
≥14 for 12.5
≥15 for 9.5
65 - 75 ≥ 8 2 - 3.5
34
4.2 MARSHALL PROPERTIES OF ASPHALT MIXTURES CONTATINING
WPB
Under this section, the effect of WPB on bulk density, stability, flow, air void, VMA and
VFA of the asphalt concrete mixtures containing WPB using different nominal maximum
aggregate sizes were analyzed and discussed.
4.2.1 Effect of WPB on Bulk Density
Effect of WPB on bulk density of the asphalt concrete mixtures for different nominal
maximum aggregate sizes were analyzed and discussed below.
Figure 10 presents bulk density of the modified asphalt concrete mixtures for all NMAS
type. The Bulk density slightly decreases through increasing of WBP replacement rate.
This is true for all NMAS types. Comparing the modified asphalt mix with the control
except 12.5mm in all types of NMAS and percentage replacement of WPB, the bulk density
of the modified asphalt mix is lower than the control asphalt mix. This may be due to the
contact point and compact ability behavior of 12.5mm NMAS.
The general trend shows that the bulk density of the modified asphalt mixtures are
decreases as the %WPB replacement increases. This is due to the relatively low density of
WPB comparing to the density of bitumen. In addition to this, increasing %WPB
replacement produces thicker WPB layers around the individual aggregates and tend to
push the aggregate particles further apart subsequently resulting lower density.
In fact, as the bulk density slightly decreases with increasing %WPB replacement, the air
void in the total mix increase and this in turn reduces the performance. From Figure 13, for
9.5mm NMAS up to 17.5% of WPB replacement, for 12.5mm NMAS from 9 – 18% of
WPB replacement and for 19mm NMAS up to 8.5% of WPB replacement regarding with
air void, the asphalt mix can fulfil the ERA standard specifications.
The bulk density of control mix at OBC are 2.365g/cm3, 2.397g/cm3 and 2.412g/cm3 for
NMAS of 9.5, 12.5 and 19mm respectively. Similarly, the bulk density for the modified
asphalt mixtures 9.5 and 19mm NMAS modified with 0 – 18% WPB are lower than the
35
control mix. However, the modified asphalt mixture having 12.5mm NMAS at 6 and 9%
replacement, the bulk density (2.435 g/cm3 and 2.403 g/cm3 respectively) is higher than
the control mix. After 9% WPB replacement, the bulk density starts to decrease. Hence, in
addition to other factors varying the NMAS in the asphalt mixtures influences the bulk
density of the mix. Generally, asphalt mix modified with higher percentages of WPB
replacement exhibit lower bulk density.
WPB has a much lower specific gravity than bitumen and mineral aggregates. In additions,
the bounding of mixture increases with increasing WPB content due to the stretchy nature
of WPB’s. As a result, at the same compaction effort (75 blows on both sides of Marshall
sample), adding WPB reduces bulk density of asphalt mixture. This reduction of bulk
density is useful in terms of hauling the asphalt mixtures from mixing plant to place of
compaction. But high bulk density is one of the design objectives following Marshall
design method. Therefore, if it needs to improve the bulk density in the field construction
more compaction efforts than the ordinary mixture would be essential.
Figure 10 Effect of WPB on Bulk density
2.300
2.320
2.340
2.360
2.380
2.400
2.420
2.440
2.460
2.480
3 6 9 12 15 18 21
Bu
lk D
en
sit
y (
g/c
m3)
WPB (%)
9.5mm 9.5_Control
12.5mm 12.5_Control
19mm 19_Control
36
4.2.2 Effect of WPB on Flow
Flow refers that the vertical deformation of the sample when the maximum load is reached.
High flow values generally indicate a plastic mix that will experience permanent
deformation under traffic loading (i.e. rutting).
Figure 11 shows the flow of the modified asphalt concrete mixtures for 9.5, 12.5 and 19mm
NMAS. In all types of NMAS, flow decreases as increasing the WPB content by weight of
OBC, until it reaches the lowest value. After it reaches the lowest value, flow start
increasing with increasing the %WPB replacement. The flow of modified asphalt concrete
decreases with WPB replacement rate of approximately up to 12% (for 9.5 & 19mm
NMAS) and 15% for 12.5mm NMAS. This because due to the resilience/ toughness
properties of WPB comparing to the asphalt binder. But when the %WPB replacement
increases beyond this because of the excess amount of WPB contents are coating the
aggregate, the flow starts to increase. Asphalt mix modified with higher percentages of
WPB exhibit higher flow.
Flow is 2.8, 3.4 and 3.4mm for the control mixtures of 9.5, 12.5 and 19mm NMAS
respectively. The minimum flow values for modified asphalt mixtures are 2.5mm (at
12%WPB), 3.2mm (at 15%WPB) and 2.7mm (at12%WPB) for 9.5, 12.5 and 19mm
respectively. Based on the flow values, except 12.5mm NMAS at 6 & 9% WPB
replacement, others satisfy the ERA standard specification. Using 9.5 and 19mm NMAS,
even if flow of modified asphalt mix decreases with increasing %WPB replacement to
some extent then starts to increase, its values are lower than the control specimens. This
may imply that excess increasing of the amount of %WPB replacement affects the interior
friction of the asphalt mixtures in a negative manner. On the contrary, 12.5mm NMAS,
although flow decreases with increasing %WPB replacement, in some of %WPB
replacement, flow values are slightly higher than the control specimen. This may be due to
the uncontrolled mixing and compaction temperatures and may be losing of some particles
from the mix.
From the above discussion, more or less the modified asphalt mixtures in some of
percentage WPB replacement, flow values are relatively lower than the control specimens.
37
Therefore, incorporating WPB in the asphalt mixtures are used to improve the rutting
resistance of the mix and also applicable to use this mix in the hot regions like Afar.
Figure 11 Effect of WPB on Flow
4.2.3 Effect of WPB on Stability
The Marshall stability provides the performance prediction measure for the Marshall mix.
Marshall stability is related to the resistance of bituminous materials to distortion,
displacement, rutting and shearing stresses. The stability is derived mainly from internal
friction and cohesion. Cohesion is the binding force of binder material while internal
friction is the interlocking and frictional resistance of aggregates. As bituminous pavement
is subjected to severe traffic loads from time to time, it is necessary to adopt bituminous
material with good stability and flow. The test measures the maximum load supported by
the test specimen at a loading rate of 50.8 mm/minute.
Figure 12 indicates the stability of the modified asphalt concrete mixtures for 9.5, 12.5 and
19mm NMAS type. The stability graph for the modified asphalt concrete mixtures having
NMAS of 9.5 and 12.5mm, shows similar trend that the stability increases as the %WPB
replacement increases until it reaches the peak and goes down. This is due to toughness
1.8
2.3
2.8
3.3
3.8
4.3
3 6 9 12 15 18 21
Flo
w (
mm
)
WPB (%)
9.5mm 9.5_Control
12.5mm 12.5_Control
19mm 19_Control
Standards
38
properties of WPB, %WPB replacement to certain extent modifies the mix and increase
stability. After that due to the reduction of bitumen which is replaced by WPB and
additional/excess coating of aggregate by WPB tends to separate aggregate interlock and
hence, the mix become loose and reduce the stability.
But in the case of NMAS of 19mm stability slightly decrease at the beginning and then
increases as increasing of %WPB replacement. To determine the maximum stability for
19mm NMAS further replacement of %WPB requires. But since the other parameters like
air void and VFA are not meet both the local and international specification, further
replacement of %WPB is meaningless.
Stability of the control mix for 9.5, 12.5 and 19mm are 8.3, 8.8 & 9kN and the modified
mix has a maximum stability of 9.8, 9.3 & 9.8kN respectively. The stability of modified
asphalt mix is higher than the control mix. Here by using WPB, it is possible to increase
the stability or performance of the mix in addition to reducing/ replacing portion of bitumen
content. From the result stability values are vary with the type of NMAS and %WPB
replacement rates. To observe the main effects of using %WPB replacement and varying
NMAS, conducting statistical analysis is important (refer section 4.5).
Figure 12 Effect of WPB on Stability
7.5
8.0
8.5
9.0
9.5
10.0
10.5
11.0
3 6 9 12 15 18 21
Sta
bilit
y (
kN
)
WPB (%)
9.5mm 9.5_Control
12.5mm 12.5_Control
19mm 19_Control
Standards
39
4.2.4 Effect of WPB on Air Void
The amount of air voids in a mixture is extremely important and closely related to stability
and durability. Figure 13 shows the air voids of modified asphalt concrete mixtures by
using NMAS of 9.5, 12.5 and 19mm. The modified asphalt concrete mixtures prepared
with all types of NMAS, air voids are increases with increasing %WPB replacement. The
portion of air voids on modified asphalt concrete mixtures increases due to the decreasing
of bulk density of asphalt mix with increasing of %WPB replacement (Figure 10).
Normally, air voids are simply calculated from theoretical maximum density and bulk
density, the effect on each density will also has another effect on the percentage air void.
Asphalt mix modified with higher percentages of WPB exhibit higher air voids. Comparing
to the other, modified asphalt mix having 19 mm has higher air void (Figure 10), because
the WPB can easily coat the fine aggregates and may not create a proper bond (by coating)
between the large aggregates, results lose asphalt concrete and hence increase the air void.
Adding WPB into asphalt mixture reduces bulk density of mixture due to the lower density
of WPB compared to asphalt and aggregate as discussed previously. WPB has also plastic
behavior thus resists compaction efforts and condensing of mixture. As a result, increasing
%WPB replacement increases the air void of asphalt mixture.
Air voids of the control mixes are 4.1, 4.1 & 4.2% for 9.5, 12.5 &19mm NMAS
respectively. Even if in all types of NMAS air void increases through increasing of %WPB
replacement, modified asphalt mixtures prepared with exceptions of 12.5mm NMAS air
voids are higher than the control specimen. This is due to the relatively better contact point
and compact ability of 12.5mm NMAS in asphalt mix. Air void below the design void
results in unstable mixture and air void above the design void result in a water permeable
mixture, hence the optimum %WPB replacement should be determined. Selection of
optimum WPB are discussed in section 4.3.
40
Figure 13 Effect of WPB on Air void
4.2.5 Effect of WPB on VMA
Figure 14 shows the VMA of modified asphalt concrete mixtures using NMAS type of 9.5,
12.5 and 19mm. Percentage VMA of modified asphalt concrete mixture increases in each
of NMAS with increasing rate of %WPB replacement. VMA depends on bulk density of
asphalt concrete, percentage bitumen content and specific gravity of the aggregate used.
Here referring Figure 10, the bulk density for all types of NMAS decreases as %WPB
replacement increases. Decreasing bulk density will result in increasing VMA. Therefore,
as %WPB replacement increases VMA also increases since the density of WPB is lower
than from each component of the mixtures.
When VMA is too low, there is not enough room in the mixture to add sufficient asphalt
binder to adequately coat the individual aggregate particles. Also, mixes with a low VMA
are more sensitive to small changes in asphalt binder content. Excessive VMA will cause
an unacceptably low mixture stability (F.L.Roberts, 1996). Results in this study shows, the
stability decreases with excess VMA content.
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
3 6 9 12 15 18 21
Air
vo
id (
%)
WPB (%)
9.5mm 9.5_Control
12.5mm 12.5_Control
19mm 19_Control
Standards
41
VMA of the control mixtures are 16.1, 14.4 & 13.1% for 9.5, 12.5 &19mm NMAS
respectively. Except 12.5mm in all the other types of NMAS the VMA of modified asphalt
mixtures are higher than the control specimen. Whereas in the case of 12.5mm NMAS,
after 9% WPB replacement the VMA is become higher than the control. This is due to the
higher bulk density of 12.5mm mix at 6 & 9% WPB replacement, VMA of the modified
asphalt mixture is lower than the control specimen.
Figure 14 Effect of WPB on VMA
4.2.6 Effect of WPB on VFA
Figure 15 presents the VFA of modified asphalt concrete mixtures using NMAS type of
9.5, 12.5 and 19mm. Asphalt concrete prepared with all type of NMAS has the same trend
that percentage of VFA steadily decrease with increasing %WPB replacement. Like other
volumetric analysis, VFA also depends on VMA and air void. Therefore, effects shown on
the VMA and air void has also influence on VFA. As shown on Figure 13, the portion of
air void increases as increasing of %WPB replacement. Similarly, VMA slightly increases
as %WPB replacement increases (Figure 14). Therefore, VFA decreases as increasing %
WPB replacement.
12.0
13.0
14.0
15.0
16.0
17.0
18.0
19.0
20.0
21.0
3 6 9 12 15 18 21
VM
A (
%)
WPB (%)
9.5mm 9.5_Control
12.5mm 12.5_Control
19mm 19_Control
Min. Standard
42
The decrease of VFA indicates a decrease of effective asphalt film thickness between
aggregates, which will result in higher low-temperature cracking and lower durability of
asphalt mixture since asphalts perform the filling and healing effects to improve the
flexibility of mixture. Therefore, high %WPB replacement is not recommended.
VFA of the control mixtures are 67.6, 71.6 & 74.3% for 9.5, 12.5 &19mm NMAS
respectively. Except 12.5mm in all the other types of NMAS the VFA of modified mixtures
are lower than the control specimen. Whereas in the case of 12.5mm NMAS, in all %WPB
replacement the VFA is become higher than the control.
Figure 15 Effect of WPB on VFA
55.0
60.0
65.0
70.0
75.0
80.0
85.0
90.0
95.0
3 6 9 12 15 18 21
VF
A (
%)
WPB (%)
9.5mm 9.5_Control
12.5mm 12.5_Control
19mm 19_Control
Standards
43
4.3 OPTIMUM WPB CONTENT DETERMINATION
“The Asphalt Institute recommends that the final selected mix design should be one whose
aggregate structure and binder content, compacted to the design number of blows, results
in 4 % air voids and satisfactorily meets all of the other established criteria in Table 5.”
(Asphalt Institute, 2014)
“The design bitumen content is obtained from the relationship between void in mix and
bitumen content determined in the Marshall test. The void in mix requirement is paramount
after which it is necessary to ensure that all of the remaining specified mix criteria are also
met.” (Ethiopian Road Authority, 2013)
The optimum WBP content is selected as the content that satisfies the minimum air void
percent or the closet percentage to air void content of 4%. Based on this, as much as
possible for each NMAS types the optimum WPB content which can satisfies the ERA
2013 standard specifications were selected.
Figure 16 OWPB content
As plotted in Figure 16 from Marshall method of mix design, the optimum %WPB
replacement contents for 9.5, 12.5 and 19mm NMAS types are 17, 13 and 7 % by weight
0
5
10
15
20
9.5 12.5 19
OW
PB
(%
)
NMAS (mm)
44
of OBC respectively. From the graph, WPB content decreases with increasing the NMAS.
From the result it is possible to conclude that the OWPB contents depends on the type of
NMAS. Because relatively 9.5mm NMAS surface area of the aggregate is large, smaller
size of the aggregate needs more WPB for coating than the larger size. Bitumen contents
are also replaced by the same percentage of WPB for respective NMAS types.
The bulk density of control mix at OBC are 2.365g/cm3, 2.397g/cm3 and 2.412g/cm3 for
NMAS of 9.5, 12.5 and 19mm respectively. Similarly, the bulk density for the modified
asphalt mixtures at the optimum WPB replacements for 9.5, 12.5 and 19mm NMAS are
2.318g/cm3, 2.387g/cm3 and 2.391g/cm3 respectively which is slightly decreases from the
control.
At the optimum WPB content, the flow of modified asphalt concrete mixtures (3.2, 3.2 &
3.0 mm) is slightly lower than the conventional asphalt concrete mixtures (2.8, 3.4 & 3.4
mm) for 9.5, 12.5 & 19 mm respectively.
Stability at optimum %WPB replacement for NMAS of 9.5, 12.5 and 19mm (9.8, 9.3 and
9.4kN respectively) are relatively higher than the conventional asphalt concrete mixtures
(8.3, 8.8 and 9.0kN).
At the optimum %WPB content, the air void of modified asphalt concrete mixtures (4.9,
3.7 & 4.7%) are slightly vary with the conventional asphalt concrete mixtures (4.1, 4.1 &
4.2%) for 9.5, 12.5 & 19 mm NMAS respectively. All this result can satisfy the local or
international specification. But for 9.5mm the air void of modified asphalt concrete (4.9%)
is higher than the conventional (4.1%).
VMA for modified asphalt concrete mixtures prepared with Optimum %WPB replacement
using NMAS of 9.5, 12.5 and 19mm (17.8, 14.7 &13.9%) are slightly higher than the
controls (16.1, 14.4 & 13.1%).
VFA results of asphalt concrete prepared with Optimum %WPB replacement using NMAS
of 9.5, 12.5 and 19mm are 72.4, 74.9 & 66% respectively. All results satisfy the minimum
ERA standard specifications.
45
Table 7 Summary of test results at the optimum WPB content
NMAS Va
(%) VMA (%)
VFA
(%)
Stability
(kN)
Flow
(mm)
Bulk
density
(g/cm3)
%OWPB
by weight
of OBC
9.5 4.9 17.8 72.4 9.8 3.2 2.318 17
12.5 3.7 14.7 74.9 9.3 3.2 2.387 13
19 4.7 13.9 66 9.4 3 2.391 7
Standard
Specification
(ERA 2013)
3 - 5
≥13 for 19
≥14 for 12.5
≥15 for 9.5
65 - 75 ≥ 8 2 - 3.5
4.4 MOISTURE SENSITIVITY OF ASPHALT MIXTURES CONAINING
WPB
Moisture damage can be defined as the loss of strength and durability in asphalt mixtures
due to the effects of moisture (D.N.Little & D.R.Jones, 2003). Moisture can damage HMA
by loss of bond between asphalt cement or mastic and fine and coarse aggregate or by
weakening of mastic due to the presence of moisture.
4.4.1 Tensile Strength Ratio (TSR)
Tensile strength ratio (TSR) is a measure of water sensitivity. It is the ratio of the tensile
strength of water conditioned specimen, (ITS wet) to the tensile strength of unconditioned
specimen (ITS dry) which is expressed as a percentage.
Figure 17 shows the effect of TSR values for all three types of NMAS. TSR values of
mixtures containing WPB are higher than control mixtures for all NMAS types. Modified
asphalt concrete mixtures prepared around the optimum WPB gives higher TSR value than
the control.
According to Asphalt Institute (MS-2), a TSR value of 0.80 (sometimes identified as 80
percent) or greater is generally considered acceptable, indicating an asphalt mixture that is
not susceptible to moisture damage. Since moisture damage is one of the most driving
46
factors for pavement distress, evaluating the water resistance of asphalt mixture is a very
important task.
As shown on Figure 17, the TSR of asphalt concrete mixtures at the optimum WPB content
for 9.5, 12.5 & 19 mm NMAS are 82.9, 84 & 84% and for control specimen are 79.7, 78.3
& 82.7% respectively. This shows that although there is a partial replacement of bitumen
by WPB, the TSR values for all type of NMAS at the optimum WPB replacement rate are
greater than 80%. Therefore, asphalt concrete mixtures modified with optimum WPB
replacement is not susceptible to moisture damage. This is because WPB acts as an
adhesive bond between aggregate and asphalt and this can lead to reduce stripping and
raveling problem.
Figure 17 TSR Test results
4.4.2 Indirect Tensile Strength (ITS) Test
Tensile strength is one of the critical parameters that should be taken into consideration for
pavement performance evaluation. The indirect tensile strength test is used to determine
the tensile properties of the bituminous mixture which can further be related to the cracking
properties of a pavement.
30.0
40.0
50.0
60.0
70.0
80.0
90.0
9.5 12.5 19
TS
R(%
)
NMAS (mm)
Control OWPB
47
The indirect tensile strength test was conducted for all conditioned and unconditioned
asphalt concrete mixtures containing different percentage of WPB replacement by weight
of OBC for different NMAS types.
Figure 18 shows conditioned and unconditioned ITS results for all three NMAS types with
different %WPB replacement. Asphalt concrete mixtures for indirect tensile strength test
was prepared by using the optimum WPB content determined from Marshall hot mix
design. For each NMAS, ITS specimens were prepared using %WPB below and above 3%
from the optimum %WPB by weight of OBC.
Using 12.5 and 19mm NMAS, the mean dry/unconditioned and wet/conditioned indirect
tensile strength of control mixtures are slightly higher compared to the mixtures prepared
with varying %WPB replacement. Replacing certain portion of bitumen contents by WPB
has a negative impact on tensile strength. On the other hand, for NMAS 9.5mm the mean
dry/unconditioned and wet/conditioned indirect tensile strength of the mixtures prepared
with 14 %WPB replacement are slightly higher compared to control mixtures. Therefore,
using WPB for asphalt mix having lower NMAS increases a little bit the ITS results.
The result of tensile strength in both wet and dry conditions replacing %WPB doesn’t have
a clear trend in varying NMAS. ITS of both conditioned and unconditioned specimens for
9.5 and 12.5mm NMAS decreases through increasing of %WPB replacement. Whereas for
19mm NMAS ITS of conditioned and unconditioned samples are increases through
increasing of %WPB replacement. This may be during conducting ITS test; it was difficult
to maintain the desired air void content (6-8%). This may also slightly affect the result of
ITS in both states.
48
Figure 18 ITS Test results
4.5 STATISTICAL ANALYSIS
Test results were statistically analyzed by using SPSS 16.0 statistical analysis software.
The actual result of the two-way ANOVA – namely, whether either of the two independent
variables or their interaction are statistically significant is shown in Table 8. As a
consequence of the subjective methodology employed to determine the bulk density, flow,
stability, air void, VMA and VFA, it was necessary to include an ANOVA statistical
analysis.
Hypothesis
A hypothesis is a formal tentative statement of the expected relationship between two or
more variables under study. Commonly there are two types of statistical hypotheses: Null
and Alternative hypothesis.
0
100
200
300
400
500
600
700
800
900
9.5 12.5 19
ITS
, kP
a
NMAS (mm)
Control_Dry OWPB_Dry Control_Wet OWPB_Wet
49
Null hypothesis, Ho
It is a hypothesis that says there is no statistical significance difference between the two
variables. It is usually the hypothesis a researcher or experimenter will try to disprove.
Alternative hypothesis, Ha
It is one that states there is a statistically significant relationship between two variables. It
is the opposite of null hypothesis.
For this research the null and alternative hypothesis are listed below.
Null hypothesis, Ho1: WPB replacement doesn’t affect the dependent variables.
Ho2: NMAS doesn’t affect the dependent variables.
Ho3: Both NMAS and WPB replacement (interaction) doesn’t affect the
dependent variables.
Alternative hypothesis, Ha1: WPB replacement affect the dependent variables.
Ha2: NMAS affect the dependent variables.
Ha3: Both NMAS and WPB replacement (interaction) affect the
dependent variables.
Two-way ANOVA analyses were performed to analyze the influence of %WPB
replacement of bitumen, varying NMAS and their interaction on the dependent variable.
The dependent variable includes the bulk density, flow, stability, air void, VMA and VFA.
The factors are the WPB content (0%, 6%, 9%, 12%, 15% and 18%), the NMAS type (9.5,
12.5 and 19mm) and the interaction of the two factors (WPB * NMAS). Both, the
dependent variables and the three factors are quantitative variables. Full outputs of SPSS
are attached in the appendix section (Appendix H).
50
Table 8 ANOVA Analysis on Tests of b/n subject’s effects
Source Dependent variables
Bulk
Density Flow Stability Air Void VMA VFA
F Sig. F Sig. F Sig. F Sig. F Sig. F Sig.
WPB 26.8 0.000 2.18 0.078 2.79 0.031 10 0.000 26.5 0.000 7.22 0.000
NMAS 94.3 0.000 16.4 0.000 2.06 0.142 64.1 0.000 189 0.000 129 0.000
WPB *
NMAS 2.91 0.009 2.13 0.048 0.52 0.864 3.2 0.005 2.99 0.008 3.54 0.002
As shown in Table 8, with dependent variable bulk density, both WPB (p = 0.000), NMAS
(p = 0.000) and interaction effects WPB * NMAS (p = 0.009) are statistically significant
at the level of α = 0.05 or 95% of confidence interval. This implies the null hypothesis is
rejected. Therefore, it is possible to conclude that WPB replacement, varying NMAS and
the interaction of the two affect the bulk density of the asphalt concrete. That is, the
statistical analysis also confirms the above-mentioned result discussions.
From the output of two-way ANOVA analysis shown on Table 8 using flow as a dependent
variable, WPB replacement (p = 0.078) is not statistically significant at 95% of confidence
interval. This indicates failed to reject the null hypothesis. Nevertheless, NMAS (p = 0.000)
and interaction effects WPB*NMAS (p = 0.048) are statistically significant at α = 0.05
level. Now, in this case the null hypothesis is rejected. Therefore, even if WPB replacement
alone doesn’t affect, varying NMAS and the interaction of NMAS*WPB replacement
affect the flow of the asphalt concrete.
From table 8, stability as a dependent variable, WPB replacement has p-values (p = 0.031).
Now since p-values are less than .05 level, %WPB replacement is statistically significant.
Hence the null hypothesis is rejected. Whereas varying NMAS (p = 0.142) and interaction
WPB*NMAS (p = 0.864) effects are not statistically significant at the level of α = 0.05.
Thus, failed to reject the null hypothesis. Therefore, even if WPB replacement alone affect
stability of the mix, varying NMAS and the interaction of NMAS*WPB replacement
doesn’t affect the stability of the asphalt concrete.
51
On Table 8 using air void as a dependent variable, WPB replacement has a p-value of p =
0.000, NMAS has a p-value of p = 0.000 and interaction of both (WPB*NMAS) has a p-
value of p = 0.005. From the result since all p-values are less than 0.05, mean difference
are statistically significant at the level of α = 0.05. Hence the null hypothesis is rejected.
This implies that, both WPB replacement, varying NMAS and the interactions of
NMAS*WPB replacement affects the air void of asphalt concrete.
Using VMA as a dependent variable shown in Table 8, WPB replacement (p = 0.000),
NMAS (p = 0.000) and interactions WPB*NMAS (p = 0.008) both are statistically
significant at the level of α = .05. Hence the null hypothesis is rejected. Therefore, both
WPB replacement, varying NMAS and the interactions of NMAS*WPB replacement
affects the VMA of asphalt concrete.
From Table 8 using VFA as a dependent variable, WPB replacement (p = 0.000), NMAS
(p = 0.000) and interactions WPB*NMAS (p = 0.002) both are statistically significant at α
= 0.05 significant level. Hence the null hypothesis is rejected. This indicates, both %WPB
replacement, varying NMAS and the interactions of NMAS*WPB replacement affects the
VFA of asphalt concrete.
Tukey's HSD test, is a post-hoc multiple comparison statistical test. It can be used on raw
data or in conjunction with an ANOVA to find means that are significantly different from
each other (i.e., a statistically significant one-way ANOVA result). The following tables,
Table 9 and Table 10 shows the post-hoc multiple comparisons between %WPB
replacement and varying NMAS respectively.
Table 9 Post-hoc multiple comparison b/n %WPB
(I)
WPB
(J)
WPB
Dependent variables with Sig. level
Bulk
Density Flow Stability Air Void VMA VFA
0%
6% 0.991 0.991 0.895 0.244 0.993 0.029
9% 0.041 0.771 0.706 0.967 0.038 1.000
12% 0.001 0.261 0.132 0.640 0.001 0.998
15% 0.000 0.456 0.063 0.030 0.000 0.508
18% 0.000 0.998 0.063 0.005 0.000 0.296
52
Table 9 shows, %WPB replacement starting from 9 - 18% comparing with the control (0%
WPB replacement), p-values of bulk density are less than 0.05 and hence mean difference
is statistically significant at the .05 level. However, there is no a statistically significant
difference between 0 and 6% WPB replacement since at 6%WPB replacement p-value is
greater than 0.05 significance level.
Using flow as a dependent variable presented on Table 9, for all percentage of WPB
replacement p-values are greater than 0.05. Which means the mean difference between 6,
9, 12, 15 and 18% WPB replacement is not statistically significant comparing with the
control (0% WPB replacement) at the .05 level. Therefore, a post-hoc multiple comparison
statistical test, Tukey's HSD test, shows that a statistically mean difference is not happening
by increasing %WPB replacement on the dependent variable (i.e. flow).
Table 9 illustrates with taking stability as a dependent variable, comparing %WPB
replacement starting from 6 - 18% with the control (0%), in all %WPB replacement p -
values are greater than 0.05. From this, means are not significantly different from each
other at .05 level. Therefore, %WPB replacement (6 – 18%) are not statistically significant
on Marshall stability.
Taking air void as dependent variable in Table 9, comparing %WPB replacement with the
control mix (0%), 6% replacement has (p = 0.244), 9% replacement has (p = 0.967), 12%
replacement has (p = 0.640). Therefore, comparing %WPB replacement from 6 – 12% with
control since p-values are greater than 0.05, mean difference is not significant at .05 level.
Therefore, there is no air void difference between control specimen and 6 up to 12%WPB
replacement. But comparing control specimen with 15 and 18% WPB replacement, p-value
are p = 0.030 and p = 0.005 respectively. Here since p-values are less than 0.05, the mean
difference is statistically significance at 95% confidence interval. Therefore, there is air
void difference between control specimen and 15 & 18%WPB replacement.
Taking VMA as a dependent variable shown on Table 9, comparing WPB replacement at
9% (p = 0.038), 12% (p = 0.001), 15% (p = 0.000) and 18% (p = 0.000) with the control
(0%), mean difference is statistically significant at 95% of confidence interval. But %WPB
53
replacement at 6% (p = 0.993) mean difference is not statistically significant with the
control specimen.
As shown on Table 9, a post-hoc multiple comparison statistical test using VFA as a
dependent variable, comparing %WPB replacement at 6% (p = 0.029) with the control
(0%) since p-value is less than 0.05, mean difference between 0 & 6% WPB replacement
is statistically significant at the .05 level. Therefore, there is a difference in VFA between
0 and 6% WPB replacement. Whereas on the other %WPB replacement like 9% (p =
1.000), 12% (p = 0.998), 15% (p = 0.508) and 18% (p = 0.296) p-values are greater than
0.05, mean difference between the control specimen is not statistically significant.
Table 10 Post-hoc multiple comparison b/n NMAS
(I)
NMAS
(J)
NMAS
Dependent variables with Sig. level
Bulk
Density Flow Stability
Air
Void VMA VFA
9.5 12.5 0.000 0.000 0.357 0.000 0.000 0.005
19 0.000 0.254 0.828 0.000 0.000 0.000
12.5 9.5 0.000 0.000 0.357 0.000 0.000 0.005
19 0.000 0.001 0.133 0.000 0.383 0.000
As observed in Table 10, based on post hoc Tukey's HSD test of ANOVA, it can be
concluded that, on bulk density there is a statistically significance difference between 9.5,
12.5 and 19mm NMAS (p = 0.000) since the p-values are less than 0.05.
As shown in Table 10 using flow as a dependent variable, p-values between 9.5 & 12.5mm
NMAS is p = 0.000 and p-values between 12.5 &19mm NMAS is p = 0.001. From this it
is possible to say that, there is a statistically significance mean difference between 9.5 &
12.5mm and between 12.5 & 19mm NMAS. But p-values between 9.5 & 19mm NMAS is
p = 0.254, which is greater than α = 0.05 significance level. Therefore, here there is no a
statistically significance mean difference between the two NMAS.
From Table 10, based on post hoc Tukey's HSD test result using stability as a dependent
variable, p-values between all types of NMAS is greater than 0.05, which is greater than α
54
= 0.05 significance level. Therefore, there is no a statistically significance mean difference
between all types of NMAS. Similarly, Varying NMAS are not statistically significant on
Marshall stability.
From Table 10 comparing p-values using air void as a dependent variable between all types
of NMAS (p = 0.000) which is less than 0.05. Here the mean difference between NMAS
are statistically significant at α = 0.05 significance level. Therefore, comparing the air void
between NMAS, there is a statistically significance mean difference between NMAS by
taking air void as a dependent variable.
VMA as a dependent variable shows on Table 10, comparing p-values between 9.5 &
12.5mm and 9.5 & 19mm NMAS (p = 0.000) which is less than 0.05. Therefore, the mean
difference between NMAS are statistically significant at α = 0.05 significance level. But
comparing p-value between 12.5 & 19mm NMAS (p = 0.383) is greater than .05
significance level. Hence, the mean difference between NMAS is not statistically
significant at α = 0.05 significance level. This is because the bulk density is nearly the same
for 12.5 & 19mm NMAS.
Based on the result in Table 10 post hoc Tukey's HSD statistical test with FVA as a
dependent variable, comparing p-values between 12.5 & 19mm and 9.5 & 19mm NMAS
(p = 0.000) and p-values between 9.5 & 12.5mm NMAS (p = 0.005) which in both case p-
values are less than 0.05. Therefore, the mean difference between NMAS are statistically
significant at α = 0.05 significance level.
55
CHAPTER FIVE
5 ECONOMIC ANALYSIS
5.1 INTRODUCTION
The growth in various types of industries together with population growth has resulted in
enormous increase in production of various types of waste material in all over the world.
The creation and disposal of non-decaying waste materials such as blast furnace slag, fly-
ash, steel slag, scrap tyres, plastics, etc., have been posing difficult problems in developed
as well as in developing countries.
Now a day’s disposal of plastic waste is considered to be a big challenge because of its
large quantity and no biodegradability nature. Plastic packaging can also cause major
environmental and economic problems. They consume a lot of energy and other natural
resources and exhaust the environment in various ways. Recycling helps to reduce energy
usage, reduce the consumption of fresh raw materials, reduce air pollution and water
pollution (from land filling) by reducing the need for conventional waste disposal and also
reduces greenhouse gases emissions. In addition of reducing greenhouse gas emissions,
recycling waste plastic bags also helps to decrease the amount of pollution in the air and
water sources.
In Bahir Dar, knowingly and unknowingly waste plastics like plastic bottles, plastic bags,
tyres, etc. are improperly disposed through the Lake Tana and it makes polluted. Bahir Dar
city has also a big problem of drainage system due to this improper disposal of waste
plastics. Around water bodies like the lake & Abay river and forests like Bezawit are
currently looks like the waste disposal sites. In the other round peoples are victim since the
fish life is endanger and the number of fish’s inside the lake and river are decreased which
results people working on fishing becomes jobless hence unemployment rate will increase.
Generally, this all will result healthy and ecological effects which affects both the fishes
and humans. Therefore, this improper waste disposal problem will influence on the
ecosystem.
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The study on this thesis focuses on showing the economic viability of using waste plastic
bags as a construction material for road construction. This will result reduction of the cost
of bitumen by incorporating WPB and reduce waste disposal problem.
5.2 RECYCLING OPPORTUNITY AND CHALLENGES
Recycling is the process of collecting and processing materials that would otherwise be
thrown away as trash and turning them into new products. Recycling helps protect the
environment and reduces the need for extracting (mining, quarrying and logging), refining
and processing raw materials. Plastics make up a huge amount of solid waste and take
centuries to break down in landfill or the ocean. Therefore, all recyclable plastics should
be recycled to reduce landfall, conserve energy and conserve the environment.
A total of 98.8 tones solid waste per day are collected and disposed from Bahir Dar city.
From this about 3.28% of waste is plastic waste (UNEP(b), Forum for Environment, 2010).
From the total plastic waste, waste plastic bag accounts 92% by weight and 89.4% by
volume (Yehuala, 2007). In the solid waste strategic management planning, high emphasis
should give for management of plastic bag waste, since it has high proportion as compared
with other types of plastic wastes.
In Bahir Dar city recycling of solid waste is not significant. Only less than 1% of solid
wastes are recycled. Dream Light plc which is the only private solid waste management
company tries to sell waste papers for paper recycling company. But on site there is no any
type or mechanism of recycling of wastes. Bahir Dar City Administration only recycle the
organic wastes to produce compost. Since there is no separate place for waste recycling
and no financial or technical support for waste recyclers, these results limited/no number
of waste recycler in the city (UNEP(a), Forum for Environment, 2010).
In addition to environmental, economic and social advantages are obtained from recycling.
There are also different advantages which includes:
o Reduces the amount of waste sent to landfills and incinerators. It helps in reducing
the volume of waste and saves a great amount of space in the landfills. Burning the
57
municipal solid waste releases some harmful gases that might affect the quality of
air. However, with recycling their impact can be reduced to a great extent.
o Conserves natural resources. Recycling is an important factor in conserving
natural resources and greatly contributes towards improving the environment.
Recycling conserves natural resources, such as wood, water, minerals, and fossil
fuels, because materials can be reused. When we make new products, we use
resources like petroleum (to make plastic bags), iron ore (to make steel cans), trees
(to make paper), aluminum (to make cans). Recycling metal, plastic and glass
decreases resource depletion, and reduces the ecosystem destruction of mining,
drilling and deforestation.
o Prevents pollution. Recycling helps to reduce the pollution caused by the extraction
and processing of virgin materials. Using recycling, less waste ends up in landfills
or thrown away on the ground and this reduces pollution.
o Saves energy. Extracting and processing raw materials to make usable materials
(like paper, plastic, metal) requires a lot of energy. Recycling often saves energy
because the products being recycled usually require much less processing to turn
them into usable materials.
o Create jobs. Recycling takes a large amount of manpower to treat and process used
or waste materials so that they can be suitable for reuse. Unlike typical waste
management and trash handling, recycling is broken down into multiple steps and
therefore requires more labor than the average trash pick-up process. In this study,
since plastic bags are light in weight women can collect this waste from street and
different waste disposal sites and can generate money. Here the study can also
empower women to fully participate on the recycling of waste plastic bags.
5.3 PLASTIC RECYCLING
From all the different materials tosses in the trash, plastics cause by far the biggest problem.
They last a long time in the environment without breaking down sometimes as much as
500 years. They're very light and they float, so plastic litter drifts across the oceans and
washes up on our beaches, killing wildlife and scarring the shoreline. The only trouble is;
plastics are relatively hard to recycle. There are many different kinds of plastic and they all
58
have to be recycled in a different way. There's so much plastic about that waste plastic
material doesn't have much value, so it's not always economic to collect. Plastic containers
also tend to be large and, unless people squash them, quickly fill up recycling bins.
All told, plastics are a bit of an environmental nightmare but that's all the more reason make
an effort to recycle them. Different plastics can be recycled in different ways. Plastic drinks
bottles are usually made from a type of clear plastic called PET (polyethylene
terephthalate) and can be turned into such things as textile insulation (for thermal jackets
and sleeping bags). Milk bottles tend to be made from a thicker, opaque plastic called
HDPE (high-density polyethylene) and can be recycled into more durable products like
flower pots and plastic pipes.
An academic research aimed at probable use of waste plastic bags in pavement structure
so as to come up with an ultimate safe disposal together with improvement in the
performance of pavement through better mix design. Significant progress also has been
made towards the incorporation of waste plastics into building and construction materials
focused mainly on cement and concrete applications.
Waste plastic from households are collected by Bahir Dar City Administration Sanitation
Agency in two ways: either by private solid waste collecting companies (Dream Light,
P.L.C) or by small scale enterprises. The agency pays 77 Birr/ton and 57 Birr/ton
respectively. In Addis Ababa, some individuals, so called 'korales', already generate
income by collecting recyclables. These korales purchase metals, plastics, reusable bottles,
worn out shoes and clothes from households, having announced their presence in the street
by shouting.
COBA recycling plc also collects plastic from different company and government institutes
with only transportation cost and retailers do this by collecting the waste plastic from
koralios. Some private companies like Ashiraf oil, water and plastic factory, Guna terara
plc, Amhara plastic manufacturing, etc. in Bahir Dar city and surrounding are trying to
recycle few types of plastic (like PET).
59
Even if there are no any plastic bag recycler companies in Bahir Dar, it would have been
better to incorporate waste plastic bags in hot mix asphalt pavement for the city road
construction.
5.4 COST-BENEFIT ANALYSIS
Not only is recycling a wonderful way to positively impact the environment, it also
supports the local and national economy. Economic cost-benefit analysis is a task which is
performed to determine the cost (direct and indirect) and benefits. Here in this study, the
cost and benefit analysis of recycling or using waste plastic bags in the hot mix asphalt
mixtures as an aggregate coat are evaluated. Analyzing the economic viability of using
waste plastic bags as an aggregate coat in hot mix asphalt mixtures depends on several
factors. These includes the cost of disposal in conventional ways, like cost due to land
filling and incineration, cost of collecting, separating the recyclable and non-recyclable
wastes, cost of washing and grinding waste plastic bags. Moreover, it depends on also the
cost of conventional bitumen and aggregates.
In this thesis, due to the limitation of organized data only a simple way of evaluating cost
and benefit are performed using the waste plastic bags in the hot mix asphalt mixtures.
Those includes both qualitative and quantitative analysis.
The qualitative analysis describes the cost and benefits of using or recycling waste plastic
bags for the hot mix asphalt mixtures. Here in qualitative analysis the cost and benefit
doesn’t quantifies numerically. It only expresses the importance of the recycled material
qualitatively. Benefit which gain qualitatively includes: saving in land fill space, saving in
natural resources, increase job opportunity (like for WPB collectors, operators, suppliers),
less pollution, less littering, reduces drainage problem, employment for unskilled laborers
will be generated etc. Cost in quantitative analysis includes cost of waste plastic bags,
construction cost may increase, increased maintenance/ rehabilitation cost, increased
transportation cost, etc.
Quantitative economic analysis was undertaken by simple comparison of the unit rate for
the production of asphalt concrete with only virgin binder and the others with 17, 13 and
60
7% waste plastic bags for NMAS of 9.5, 12.5 and 19mm respectively being used as an
aggregate coating to partially substitute the virgin binder with waste plastic bags in hot mix
asphalt pavement construction.
For quantitative analysis to make a simple comparison the following assumption was made
for the conventional and modified asphalt mixtures.
o Labor and machine costs of asphalt concrete production for both cases are assumed
to be equal.
o Hauling distances for waste plastic bags and bitumen assumed to be different but
not considered explicitly.
Unit rate for natural aggregates and bitumen have been gathered from Amhara Road Work
Enterprise (ARWE), China Civil Engineering Construction Corporation (CCECC) and IFH
Engineering General Contractor for asphalt road projects, where the projects are located
around Bahir Dar.
Unit rate of waste plastic bags was obtained from other types of plastic wastes (like PET,
HDPE) of Dream Lights P.L.C, and Bahir Dar City Administration, Sanitation
Administration Agency since waste plastic bags are not currently recycled.
Conventional Hot Mix Asphalt Concrete
The average cost of aggregate and bitumen for this analysis was taken from ARWE,
CCECC and IFH Engineering. The cost covers also the mixing plant. The cost comparisons
are done for all 9.5, 12.5- and 19-mm types of NMAS with simple calculation.
i. Using NMAS of 9.5 mm
o Total aggregate cost = Purchasing + Transportation + Wastage + Storage Cost
= = 1273.17 Birr/m3
o Cost of 60/70 penetration grade bitumen = 34,920.00 Birr/m3
o Cost of 60/70 penetration grade bitumen for 5.9% OBC = 2,060.28 Birr/m3
o Total labor cost = 106.70 Birr/m3
o Total equipment cost = 1,142.85 Birr/m3
o Total direct cost = 4,583.00 Birr/m3
61
o Indirect cost (15% of direct cost) = 687.45 Birr/m3
Therefore, total unit rate = 5,270.45 Birr/m3 for NMAS of 9.5mm
ii. Using NMAS of 12.5 mm
o Total aggregate cost = Purchasing + Transportation + Wastage + Storage Cost
= = 1273.17 Birr/m3
o Cost of 60/70 penetration grade bitumen = 34,920.00 Birr/m3
o Cost of 60/70 penetration grade bitumen for 5.5% OBC = 1,920.60 Birr/m3
o Total labor cost = 106.70 Birr/m3
o Total equipment cost = 1,142.85 Birr/m3
o Total direct cost = 4,443.32 Birr/m3
o Indirect cost (15% of direct cost) = 666.50 Birr/m3
Therefore, total unit rate = 5,109.82 Birr/m3 for NMAS of 12.5mm
iii. Using NMAS of 19 mm
o Total aggregate cost = Purchasing + Transportation + Wastage + Storage Cost
= = 1273.17 Birr/m3
o Cost of 60/70 penetration grade bitumen = 34,920.00 Birr/m3
o Cost of 60/70 penetration grade bitumen for 4.9% OBC = 1,711.08 Birr/m3
o Total labor cost = 106.70 Birr/m3
o Total equipment cost = 1,142.85 Birr/m3
o Total direct cost = 4,233.80 Birr/m3
o Indirect cost (15% of direct cost) = 635.07 Birr/m3
Therefore, total unit rate = 4,868.87 Birr/m3 for NMAS of 19 mm
Indirect costs are costs which are not directly related to production of hot mix asphalt
concrete like administration and personnel costs.
Modified Hot Mix Asphalt Concrete
For cost benefit analysis, the cost of another types of waste plastic like PET are used for
comparisons purposes since waste plastic bags has not sold or recycled by the recycler
companies. On average cost of waste plastics has 850.00 Birr/m3 (from oral interviews and
62
referring from similar works). This cost includes cost of collection, separating, washing
and grinding.
i. Using NMAS of 9.5 mm
o Total aggregate cost = Purchasing + Transportation + Wastage + Storage Cost
= = 1273.17 Birr/m3
o Cost of 60/70 penetration grade bitumen = 34,920.00 Birr/m3
o Cost of 60/70 penetration grade bitumen for 4.9% OBC = 1,710.03 Birr/m3
o Cost of WPB = 850.00 Birr/m3 (from phone and oral communications)
o Cost of 17% of WPB = 144.50 Birr/m3
o Total labor cost = 106.70 Birr/m3
o Total equipment cost = 1,142.85 Birr/m3
o Total direct cost = 4,377.25 Birr/m3
o Indirect cost (15% of direct cost) = 656.59 Birr/m3
Therefore, total unit rate = 5,033.84 Birr/m3 for NMAS of 9.5mm
ii. Using NMAS of 12.5 mm
o Total aggregate cost = Purchasing + Transportation + Wastage + Storage Cost
= = 1273.17 Birr/m3
o Cost of 60/70 penetration grade bitumen = 34,920.00 Birr/m3
o Cost of 60/70 penetration grade bitumen for 4.79% OBC = 1,670.92 Birr/m3
o Cost of WPB = 850.00 Birr/m3
o Cost of 13% of WPB = 110.50 Birr/m3
o Total labor cost = 106.70 Birr/m3
o Total equipment cost = 1,142.85 Birr/m3
o Total direct cost = 4,304.14 Birr/m3
o Indirect cost (15% of direct cost) = 645.62 Birr/m3
Therefore, total unit rate = 4,949.76 Birr/m3 for NMAS of 12.5mm
63
iii. Using NMAS of 19 mm
o Total aggregate cost = Purchasing + Transportation + Wastage + Storage Cost
= = 1273.17 Birr/m3
o Cost of 60/70 penetration grade bitumen = 34,920.00 Birr/m3
o Cost of 60/70 penetration grade bitumen for 4.5% OBC = 1,591.30 Birr/m3
o Cost of WPB = 850.00 Birr/m3
o Cost of 7% of WPB = 59.50 Birr/m3
o Total labor cost = 106.70 Birr/m3
o Total equipment cost = 1,142.85 Birr/m3
o Total direct cost = 4,173.52 Birr/m3
o Indirect cost (15% of direct cost) = 626.03 Birr/m3
Therefore, total unit rate = 4,799.55 Birr/m3 for NMAS of 19 mm
Comparing the conventional and modified total unit rate for all types of NMAS shows there
is a good advantage of using WPB in the asphalt mixtures. Using the modified hot mix
asphalt concrete the project can save 4.5, 3.1 and 1.4% budget from the total unit rate for
9.5, 12.5 and 19mm NMAS respectively. Since the percentage of WPB used are increased
through decreasing the nominal maximum aggregate size, comparing from the other sizes,
9.5 mm has more reduction of cost (4.5 % from the total unit rate). More over using WPB
in asphalt mixture has a benefit qualitatively, it has also advantaged quantitatively by
reducing the bitumen consumptions. In terms of cost also 350.25, 249.68 and 119.78
Birr/m3 for 9.5, 12.5 and 19 mm NMAS respectively can save by incorporating WPB in
the hot mix asphalt mixtures.
In general, regardless of the aggregate size that the project use and production of asphalt
concrete with the addition of WPB, the project benefited with 1 - 5% cost reduction per
unit rate.
64
CHAPTER SIX
6 CONCLUSION AND RECOMMENDATION
6.1 CONCLUSIONS
The objective of this study is to investigate the effect of using waste plastic bags as an
aggregate coating using 9.5, 12.5 &19mm NMAS, where the results can be concluded as
follows:
o As percentage WPB replacement increments, the result of Marshall stability greater
than the control specimen and satisfy the local and international standards
specifications.
o The flow of modified asphalt concrete decreases with WPB replacement rate of
approximately up to 12% (for 9.5 & 19mm NMAS) and 15% for 12.5mm NMAS.
Thus, incorporating WPB in the asphalt mixtures improve the deformation/ rutting
resistance of the mix.
o Asphalt mix modified with WPB replacement shows lower bulk density & VFA;
and higher flow, air void & VMA. But the stiffness of the modified mix is increased
approximately up to 15% replacement. This decrease in bulk density can explained
to be as a result of the low density of added plastic material.
o Analyzing statistically varying NMAS, WPB replacement & interactions has a
significant effect on all Marshall properties at 0.05 significance level except
stability (both varying NMAS & interaction) and flow (WPB replacement).
o From Marshall hot mix design, the optimum WPB replacement content of 17, 13
and 7% are obtained for 9.5, 12.5 & 19mm NMAS respectively. With this optimum
WPB, all the other Marshall properties (like stability, flow, air void, VMA & VFA)
are met the local and international standard specifications.
o TSR result at the optimum WPB replacement are greater than 80%. Which indicates
the mix is not susceptible to moisture damage for all NMAS.
o From economic analysis, waste plastic bag is economically viable in terms of cost
reduction and creating of ecofriendly environment.
65
6.2 RECOMMENDATIONS
From the results of this study and on practical engineering considerations, it is
recommended that the following special provisions be developed.
o To allow waste plastic bags to be used as an aggregate coat in asphalt concrete.
o To allow a maximum of 17, 13 and 7 percent of waste plastic bags to be used in
asphalt mixes by weight of optimum bitumen content for 9.5, 12.5 and 19mm
nominal maximum aggregate size respectively.
o It is recommended to use 9.5mm NMAS modified asphalt mix on parking lots,
12.5mm on wearing course layers and 19mm on binder course layers.
o It’s recommended to encourage the field application and evaluation to find out the
performance of hot mix asphalt containing waste materials. Constructing test road
sections using WPB modified asphalt mix for further field studies of its
performance are recommended.
o The quantitative economic analysis better to be done by taking in to consideration
different factors and indirect costs like land fill cost, increased cost of construction
and increased in maintenance & rehabilitation cost.
66
6.3 FUTURE STUDY
The following further studies are recommended to work on waste plastic bags (WPB) in
the area of road constructions.
o Performance tests on asphalt mixtures using Asphalt Performance Mixture Tester
(AMPT), Flow Number (FN), Fatigue and others.
o Modification of binder properties by incorporating waste plastic bags using
Dynamic Shear Rheology (DSR) tests.
o Using various waste plastic types, different methods of adding waste plastic in the
asphalt mixtures and size of waste plastic are recommended.
67
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Thesis in Addis Ababa university.
Z.Kalantar, A.Mahrez, & M.R.Karim. (2010). Properties of bituminous binder modified
with waste Polyethylene Terephthalate. proceedings of Malaysian Universities
Transportation Research Forum & Conferences. Malaysia.
69
APPENDIX
APPENDIX A: PHYSICAL PROPERTIES OF AGGREGATE
i. Flakiness Index (FI)
ii. Aggregate Crushing Value (ACV)
37.5 1725.6 1725.6 0 0.0 - 0.0
28 1731.6 1731.6 0 0.0 - 0.0
20 1625.4 1625.4 0 0.0 - 0.0
14 1349.3 1569.3 220 18.3 220.0 84.0
10 1316.8 1915.3 598.5 49.7 598.5 105.0
6.3 1350.2 1735.2 385.0 32.0 385.0 122.0
Total 1203.5 Total M2= 1203.5 M3= 311
(M3*100)/M2
26
Percentage of mass
retained on each
sieve
Mass retained more
than 5% on each
sieve (g)
Flakiness Index (BS 812)
Mass passing
through thickness
gauge(g)
Flakiness index (%) =
=
Sieve size(mm)Mass of
sieve(g)
Mass of
sieve+sample
(g)
Mass of sample
retained on each
sieve(g)
Type of test Trials
Net mass of
test specimen
M0, (g)
Net mass of
aggregate retained
on 2.36mm test
sieve M1, (g)
Net mass of
aggregate passing
the 2.36mm test
sieve M2, (g)
Aggregate Crushing
Value =
(M2x100%)/M0
Average
1 3144 2860.0 284.0 9.0
2 3109 2843.5 265.5 8.5
Aggregate Crushing Value(ACV) (BS 812-110)
Aggregate
Crushing
Value(ACV)
(BS 812-110)
9
70
iii. Loss Angeles Abrasion (LAA)
iv. Aggregate Impact Value (AIV)
v. Ten percent Fines Value (TFV)
B
Passing(mm)
37.5
25.0
19.0 2500.5
12.5 2500.5
5001
5001
4410.0
591.0
12
Loss Angeles Abrasion (ASTM-C131)
Mass of test sample passed on 1.70mm (No.12) sieve, M1-M2 (g) =
Los Angeles Abrasion Value(%)
25.0
19.0
12.5 2500
Grading of test sample
Sieve size(mm) Mass of sample
taken(g)
Mass of soil sample to be taken,
according to the standard(g)Retained on (mm)
9.5 2500
Total 500010
Original mass of test sample, M1(g) =
Mass of test sample retained on 1.70mm (No.12) sieve, M2(g) =
Type of test Trials
Net mass of
test specimen
M0, (g)
Net mass of
aggregate retained
on 2.36mm test
sieve M1, (g)
Net mass of
aggregate passing
the 2.36mm test
sieve M2, (g)
Aggregate Crushing
Value =
(M2x100%)/M0
Average
1 390.0 364.0 26.0 6.7
2 388.5 361.0 27.5 7.1
Aggregate Impact Value(AIV) (BS 812-112)
Aggregate Impact
Value(AIV)
(BS 812-112)7
Test specimens in a dry condition
Trials
Net mass of
test
specimen
M1, (g)
Net mass of
aggregate
retained on
2.36mm test
sieve M2, (g)
Net mass of
aggregate passing
the 2.36mm test
sieve M3, (g)
The maximum
force f, (KN)
Percentage of
material passing
2.36mm sieve m,
= (M3x100%)/M1
Ten Percent
Fines Value,
TFV =
(14*f/(m+4))
1 3071.5 2692.0 379.5 571.4 12.4 489.1
2 3194.5 2794.0 400.5 571.4 12.5 483.7
490
Ten percent Fines Value(TFV) (BS 812-111)
71
vi. Atterberg's Limit
Can NoMass of can
(g)
Mass of can+ wet soil
(g)
Mass of
can+dry soil (g)
Moisture content,
w(%)
Cone penetration
(mm)
1A 37.6 57.7 53.8 24.1 15.0
2A 37.2 58.7 54.4 25.0 18.2
3A 37.1 57.8 53.5 26.2 21.0
4A 37.1 59.0 54.3 27.3 24.9
25
Note :- Liquid limit is the moisture content corresponding to penetration of 20 mm
Can NoMass of can
(g)
Mass of can+wet
soil (g)
Mass of
can+dry soil
(g)
Moisture content,
w(%)
25
-
-
Remark: The material is Non-plastic (NP).
Trials = 1 2
140 140
137.5 137.4
Average = 1.79 1.86
Plasticity Index, (%) =
Liquid Limit(LL)
Atterberg's Limit, BS:1377-1990
Liquid Limit,LL(%)
Plastic Limit(PL)
Liquid Limit, (%) =
Plastic Limit, (%) = s
Shrinkage Limit(SL)
Original length of the specimen, Lo (in mm) =
Length of the oven-dry specimen, Ld (in mm) =
Linear Shrinkage, % = 1.8
23
24
25
26
27
28
12 14 16 18 20 22 24 26 28
Mo
istu
re C
onte
nt
,w (
%)
Cone penetration,d(mm)
72
vii. Specific Gravity & Water Absorption of Coarse Aggregate
viii. Specific Gravity & Absorption of Fine Aggregate
ix. Specific Gravity of Mineral Filler
2001.5 2020 1250.5 2.625 2.601 2.665 0.92 12.5
2000 2039.5 1261 2.620 2.569 2.706 1.98 9.5
2000 2040 1261 2.619 2.567 2.706 2.00 4.75
Average = 1.63
Where:- A = Weight of oven dry sample in air in g
B = Weight of Saturated - Surface dry sample in air in g
C = Weight of Saturated - Surface dry sample in water in g
Water
Absorption , %
Remark
(Agg. Size)
Specific Gravity & Water Absorption of Coarse Aggregate, ASTM: C 127 - 88
A B CBulk Specific
gravity (SSD)
Bulk Specific
gravity (dry)
Apparent Specific
gravity
481.9 901.2 1224.9 500 2.836 2.733 3.046 3.8 2.36
480.5 901.2 1225 500 2.838 2.727 3.066 4.1 1.18
476.3 901.2 1224.2 500 2.825 2.691 3.107 5.0 0.6
476.3 901.2 1221 500 2.775 2.643 3.043 5.0 0.3
474.1 901.2 1219.5 500 2.752 2.609 3.043 5.5 0.15
448 901.2 1218.5 500 2.737 2.452 3.428 11.6 0.075
Where:- A = Mass of oven dry specimen in air, g
B = Mass of pycnometer filled with water, g
C = Mass of pycnometer with specimen and water to calibration mark, g and
S = Mass of saturated surface-dry specimen, g
Absorption ,
%RemarkA B C S
Bulk Specific
gravity (SSD)
Bulk Specific
gravity (dry)
Apparent
Specific gravity
Specific Gravity & Absorption of Fine Aggregate, AASHTO T 84-00, ASTM C 128-97
24.9 96.3 112.3 0.9991 2.798 2.795 2.797
25.1 102.1 118.5 0.9991 2.885 2.882 2.884
25.1 101 117.1 0.9991 2.789 2.786 2.788
Average = 2.823
Where:- Mo = Mass of oven dry specimen, g
Ma = Mass of pycnometer filled with water at temperature T b , g
Mb = Mass of pycnometer filled with water and specimen at temperature T b , g
K= Temperature correction
T b = Temprature of the contents of the pycnometer when mass Mb was determined, oC.
Mo Ma Mb KBulk Specific
gravity (dry)
Bulk Specific
gravity @230C
Bulk Specific
gravity @200C
Specific Gravity of Mineral Filler, ASTM D854
73
APPENDIX B: PHYSICAL PROPERTIES OF BITUMEN
Trials 1 2 3Mean
Results
Flash Point oC 294 275 280 283
Penetration at 25oC, 100g, 5 sec 62 64 60 62
Ductility at 25 oC (cm) 111 103 107 100
+
Softening Point (oC) 46 51 47 48
Loss on Heating (%) 0.4 0.1 0.2 0.2
Residue penetration,at 25oC,
100g , 5 sec (%)57 53 55 55
Residue ductility at 25oC (cm) 78 85 79 81
Specific gravity at 25oC (g/cm³) 1.014 1.019 1.023 1.019
74
APPENDIX C: FTIR IR SPECTRUM TABLE BY FREQUENCY RANGE
Frequency Range Absorption (cm-1) Appearance Group Compound Class
4000-3000 cm-1 3700-3584
medium,
sharp O-H stretching alcohol
3550-3200 strong, broad O-H stretching alcohol
3500 medium N-H stretching primary amine
3400-3300 medium N-H stretching aliphatic primary
amine
3350-3310 medium N-H stretching secondary amine
3300-2500 strong, broad O-H stretching carboxylic acid
3200-2700 weak, broad O-H stretching alcohol
3000-2800 strong, broad N-H stretching amine salt
3000-2500 cm-1 3333-3267 strong, sharp C-H stretching alkyne
3100-3000 medium C-H stretching alkene
3000-2840 medium C-H stretching alkane
2830-2695 medium C-H stretching aldehyde
2600-2550 weak S-H stretching thiol
2400-2000 cm-1 2349 strong O=C=O stretching carbon dioxide
2275-2250 strong, broad N=C=O stretching isocyanate
2260-2222 weak CΞN stretching nitrile
2260-2190 weak CΞC stretching alkyne
2175-2140 strong S-CΞN stretching thiocyanate
2160-2120 strong N=N=N stretching azide
2150 C=C=O stretching ketene
2145-2120 strong N=C=N stretching carbodiimide
2140-2100 weak CΞC stretching alkyne
2140-1990 strong N=C=S stretching isothiocyanate
2000-1900 medium C=C=C stretching allene
2000 C=C=N stretching ketenimine
2000-1650 cm-1 2000-1650 weak C-H bending
aromatic
compound
1818 strong C=O stretching anhydride
1815-1785 strong C=O stretching acid halide
1800-1770 strong C=O stretching conjugated acid
halide
1775 strong C=O stretching conjugated
anhydride
1770-1780 strong C=O stretching vinyl / phenyl ester
1760 strong C=O stretching carboxylic acid
1750-1735 strong C=O stretching esters
1750-1735 strong C=O stretching δ-lactone
1745 strong C=O stretching cyclopentanone
75
1740-1720 strong C=O stretching aldehyde
1730-1715 strong C=O stretching α,β-unsaturated
ester
1725-1705 strong C=O stretching aliphatic ketone
1720-1706 strong C=O stretching carboxylic acid
1710-1680 strong C=O stretching conjugated acid
1710-1685 strong C=O stretching conjugated
aldehyde
1690 strong C=O stretching primary amide
1690-1640 medium C=N stretching imine / oxime
1685-1666 strong C=O stretching conjugated ketone
1680 strong C=O stretching secondary amide
1680 strong C=O stretching tertiary amide
1650 strong C=O stretching δ-lactam
1670-1600 cm-1 1678-1668 weak C=C stretching alkene
1675-1665 weak C=C stretching alkene
1675-1665 weak C=C stretching alkene
1662-1626 medium C=C stretching alkene
1658-1648 medium C=C stretching alkene
1650-1600 medium C=C stretching conjugated alkene
1650-1580 medium N-H bending amine
1650-1566 medium C=C stretching cyclic alkene
1648-1638 strong C=C stretching alkene
1620-1610 strong C=C stretching α,β-unsaturated
ketone
1600-1300 cm-1 1550-1500 strong N-O stretching nitro compound
1465 medium C-H bending alkane
1450 medium C-H bending alkane
1390-1380 medium C-H bending aldehyde
1385-1380 medium C-H bending alkane
1400-1000 cm-1 1440-1395 medium O-H bending carboxylic acid
1420-1330 medium O-H bending alcohol
1415-1380 strong S=O stretching sulfate
1410-1380 strong S=O stretching sulfonyl chloride
1400-1000 strong C-F stretching fluoro compound
1390-1310 medium O-H bending phenol
1372-1335 strong S=O stretching sulfonate
1370-1335 strong S=O stretching sulfonamide
1350-1342 strong S=O stretching sulfonic acid
1350-1300 strong S=O stretching sulfone
1342-1266 strong C-N stretching aromatic amine
1310-1250 strong C-O stretching aromatic ester
1275-1200 strong C-O stretching alkyl aryl ether
1250-1020 medium C-N stretching amine
76
1225-1200 strong C-O stretching vinyl ether
1210-1163 strong C-O stretching ester
1205-1124 strong C-O stretching tertiary alcohol
1150-1085 strong C-O stretching aliphatic ether
1124-1087 strong C-O stretching secondary alcohol
1085-1050 strong C-O stretching primary alcohol
1070-1030 strong S=O stretching sulfoxide
1050-1040 strong, broad CO-O-CO stretching anhydride
1000-650 cm-1 995-985 strong C=C bending alkene
980-960 strong C=C bending alkene
895-885 strong C=C bending alkene
850-550 strong C-Cl stretching halo compound
840-790 medium C=C bending alkene
730-665 strong C=C bending alkene
690-515 strong C-Br stretching halo compound
600-500 strong C-I stretching halo compound
900-700 cm-1 880 ± 20 strong C-H bending 1,2,4-trisubstituted
880 ± 20 strong C-H bending 1,3-disubstituted
810 ± 20 strong C-H bending 1,4-disubstituted or
780 ± 20 strong C-H bending 1,2,3-trisubstituted
755 ± 20 strong C-H bending 1,2-disubstituted
750 ± 20 strong C-H bending monosubstituted
77
APPENDIX D: EQUATIONS FOR MARSHALL AND ITS TEST
iii. Bulk specific gravity for the total aggregate, Gsb
n
n
nsb
G
P
G
P
G
P
PPPG
...
...
2
2
1
1
21
++
++=
where: P1, P2... Pn = individual percentages by weight of aggregates
G1, G2...Gn = individual bulk specific gravities of aggregates
iv. Effective specific gravity of aggregate, Gse
b
b
mm
bse
G
P
G
PG
−
−=
100
100
where: Gmm = maximum specific gravity of mixed material (no air voids);
Pb = bitumen content at which ASTM D2041 test (Gmm) was performed,
percent by total weight of mixture;
Gb = specific gravity of bitumen
v. Maximum theoretical specific gravity of mixture (no air voids), Gmm
b
b
se
smm
G
P
G
PG
+
=100
where: Ps = aggregate content, percent by total weight of mixture
Pb = bitumen content, percent by total weight of mixture
Gse = effective specific gravity of aggregate
Gb = specific gravity of bitumen
vi. Absorbed bitumen, percent by weight of aggregate, Pba
sbse
bsbseba
GG
GGGP
)(100 −=
78
where: Gse = effective specific gravity of aggregate
Gsb = bulk specific gravity of total aggregate
Gb = specific gravity of bitumen
vii. Effective bitumen content, percent by total weight of mix, Pbe
100
sbabbe
PPPP −=
where: Pb = bitumen content, percent by total weight of mix
Pba = absorbed bitumen, percent by weight of aggregate
Ps = aggregate content, percent by total weight of mix
viii. Voids in Mineral Aggregate, VMA
sb
smb
G
PGVMA −= 100
where: Gmb = bulk specific gravity of compacted mix
Gsb = bulk specific gravity of total aggregate
Ps = aggregate content, percent by total weight of mix
ix. Air voids in compacted mix, percent of total volume, Va
100)(mm
mbmma
G
GGV
−=
where: Gmm = maximum specific gravity of mix
Gmb = bulk specific gravity of compacted mix
x. Voids Filled with Asphalt, VFA
100)(VMA
VVMAVFA a−
=
where: VMA = voids in mineral aggregate, per cent of bulk volume
Va = air voids in compacted mix, percent of total volume
79
APPENDIX E: MARSHALL MIX DESIGN RESULT FOR OBC
DETERMINATION
i. Using NMAS of 9.5 mm
Marshall Hot Mix Design Test Property Curves for NMAS of 9.5 mm
R² = 0.9015
0
2
4
6
8
10
12
14
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Air
vo
id（
％）
Pb (%)
R² = 0.8865
15.8
16
16.2
16.4
16.6
16.8
4.0 4.5 5.0 5.5 6.0 6.5 7.0
VM
A（％）
Pb (%)
R² = 0.9588
30
40
50
60
70
80
90
100
4.0 4.5 5.0 5.5 6.0 6.5 7.0
VF
A（％）
Pb (%)
R² = 0.9947
2.300
2.320
2.340
2.360
2.380
2.400
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Unit
wei
ght（
g/c
m³）
Pb (%)
R² = 0.9823
5
6
7
8
9
10
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Sta
bil
ity（
KN）
Pb (%)
R² = 0.9858
2
2.5
3
3.5
4
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Flo
w V
alue（
mm）
Pb (%)
80
ii. Using NMAS of 12.5 mm
Marshall Hot Mix Design Test Property Curves for NMAS of 12.5 mm
R² = 0.9929
0
2
4
6
8
10
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Air
vo
id（
％）
Pb (%)
R² = 0.9676
14
14.5
15
15.5
16
16.5
4.0 4.5 5.0 5.5 6.0 6.5 7.0
VM
A（
％）
Pb (%)
R² = 0.9954
30
40
50
60
70
80
90
100
4.0 4.5 5.0 5.5 6.0 6.5 7.0
VF
A（％）
Pb (%)
R² = 0.9922
2.300
2.320
2.340
2.360
2.380
2.400
2.420
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Unit
wei
ght（
g/c
m³）
Pb (%)
R² = 0.6242
5
6
7
8
9
10
11
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Sta
bil
ity（
KN）
Pb (%)
R² = 0.9858
2
2.5
3
3.5
4
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Flo
w V
alue（
mm）
Pb (%)
81
iii. Using NMAS of 19 mm
Marshall Hot Mix Design Test Property Curves for NMAS of 19 mm
R² = 0.9948
0
2
4
6
8
10
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Air
vo
id(%
)
Pb (%)
R² = 0.99
11
12
13
14
15
4.0 4.5 5.0 5.5 6.0 6.5 7.0
VM
A (
%)
Pb (%)
R² = 0.9973
30
40
50
60
70
80
90
100
4.0 4.5 5.0 5.5 6.0 6.5 7.0
VF
A(%
)
Pb (%)
R² = 0.9961
2.200
2.300
2.400
2.500
2.600
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Unit
wei
ght（
g/c
m³）
Pb (%)
R² = 0.9982
5
6
7
8
9
10
11
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Sta
bil
ity（
KN）
Pb (%)
R² = 0.9809
3
3.2
3.4
3.6
3.8
4
4.0 4.5 5.0 5.5 6.0 6.5 7.0
Flo
w V
alue（
mm）
Pb (%)
82
APPENDIX F: MARSHALL MIX DESIGN RESULT WITH VARYING
PROPORTION OF WPB
NMAS WPB by wt
of OBC (%) Gmb
Va
(%)
VMA
(%)
VFA
(%)
Stability
(KN)
Flow
(mm)
9.5
0 2.372 3.9 15.8 75.7 7.8 2.8
0 2.362 4.3 16.2 73.6 7.9 2.3
0 2.362 4.3 16.2 73.7 9.1 3.3
6 2.352 4.3 16.6 74.1 8.7 2.5
6 2.348 4.5 16.7 73.4 9.7 2.8
6 2.351 4.3 16.6 73.9 8.4 2.8
9 2.359 3.8 16.3 76.7 8.8 2.5
9 2.349 4.2 16.7 74.9 9.6 2.4
9 2.320 5.4 17.7 69.5 9.4 2.8
12 2.340 4.4 17.0 74.2 9.6 2.5
12 2.324 5.0 17.6 71.3 9.2 2.2
12 2.341 4.3 16.9 74.5 10.4 2.8
15 2.331 4.6 17.3 73.7 9.7 2.8
15 2.320 5.0 17.7 71.7 9.3 2.7
15 2.327 4.7 17.5 72.9 10.4 2.7
18 2.316 5.0 17.8 72.2 9.3 3.5
18 2.310 5.2 18.1 71.1 9.4 3.5
18 2.315 5.0 17.9 72.0 10.5 3.6
12.5
0 2.397 4.1 14.4 71.5 9.5 3.4
0 2.396 4.1 14.4 71.4 9.9 3.5
0 2.398 4.0 14.3 71.8 7.0 3.2
6 2.424 2.6 13.4 80.3 8.6 3.9
6 2.437 2.1 12.9 83.7 8.8 3.6
6 2.443 1.8 12.7 85.5 8.6 3.3
9 2.402 3.3 14.2 76.4 9.2 3.6
9 2.407 3.1 14.0 77.6 8.7 3.5
9 2.401 3.4 14.2 76.1 8.5 3.4
12 2.395 3.4 14.4 76.3 9.0 3.7
12 2.397 3.4 14.4 76.7 9.2 3.3
12 2.378 4.1 15.0 72.7 9.4 3.2
15 2.378 3.9 15.1 73.9 9.2 3.4
15 2.371 4.2 15.3 72.4 9.7 3.1
83
15 2.398 3.1 14.3 78.3 9.1 3.1
18 2.353 4.7 15.9 70.3 9.8 3.5
18 2.378 3.7 15.0 75.3 9.6 3.4
18 2.393 3.1 14.5 78.5 8.2 3.1
19
0 2.403 4.6 13.4 65.8 9.4 3.0
0 2.417 4.1 12.9 68.6 8.7 3.6
0 2.416 4.1 12.9 68.5 9.0 3.7
6 2.412 3.9 13.1 70.2 10.0 3.4
6 2.389 4.8 13.9 65.4 8.8 3.3
6 2.399 4.4 13.5 67.5 9.5 2.4
9 2.364 5.7 14.8 61.6 10.0 2.6
9 2.384 4.9 14.1 65.4 8.8 3.4
9 2.370 5.4 14.6 62.7 9.1 2.8
12 2.383 4.8 14.1 66.2 9.2 1.9
12 2.328 6.9 16.1 56.9 9.4 3.0
12 2.389 4.5 13.9 67.5 9.7 3.2
15 2.347 6.0 15.4 61.0 10.1 2.9
15 2.341 6.3 15.7 60.0 9.3 3.0
15 2.332 6.6 16.0 58.6 9.2 2.6
18 2.333 6.4 15.9 59.7 9.9 3.0
18 2.339 6.2 15.7 60.6 9.6 2.8
18 2.328 6.6 16.1 58.9 9.7 3.0
Summary of mean Marshall test results
NMAS
WPB by
wt. of
OBC (%)
Gmb Gmm Va
(%)
VMA
(%)
VFA
(%)
Stability
(KN)
Flow
(mm) Gse Pba Pbe
9.5
0 2.365 2.467 4.1 16.1 74.3 8.3 2.8 2.709 0.80 5.15
6 2.350 2.457 4.4 16.6 73.8 8.9 2.7 2.699 0.65 4.94
9 2.343 2.452 4.5 16.9 73.6 9.3 2.6 2.694 0.58 4.83
12 2.335 2.447 4.6 17.2 73.3 9.7 2.5 2.689 0.50 4.72
15 2.326 2.442 4.8 17.5 72.8 9.8 2.7 2.684 0.43 4.61
18 2.314 2.437 5.1 17.9 71.8 9.7 3.5 2.679 0.36 4.49
84
12.5
0 2.397 2.499 4.1 14.4 71.6 8.8 3.4 2.730 1.19 4.37
6 2.435 2.489 2.2 13.0 83.1 8.7 3.6 2.720 1.06 4.17
9 2.403 2.485 3.3 14.1 76.7 8.8 3.5 2.716 1.00 4.06
12 2.390 2.480 3.6 14.6 75.2 9.2 3.4 2.711 0.93 3.96
15 2.382 2.475 3.8 14.9 74.8 9.3 3.2 2.706 0.86 3.86
18 2.375 2.470 3.9 15.2 74.6 9.2 3.3 2.701 0.79 3.77
19
0 2.412 2.519 4.2 13.1 67.6 9.0 3.4 2.725 1.23 3.73
6 2.400 2.510 4.4 13.5 67.6 9.4 3.0 2.717 1.10 3.56
9 2.373 2.506 5.3 14.5 63.2 9.3 2.9 2.714 1.06 3.45
12 2.367 2.502 5.4 14.7 63.2 9.4 2.7 2.710 1.00 3.36
15 2.340 2.497 6.3 15.7 59.8 9.5 2.9 2.705 0.92 3.29
18 2.333 2.493 6.4 15.9 59.7 9.8 3.0 2.701 0.87 3.19
85
APPENDIX G: ITS TEST RESULTS
NMAS
WPB by
wt. of
OBC (%)
Tensile
Strength
(S1), kPa
(dry)
Tensile
Strength
(S2), kPa
(wet)
Average
Tensile
Strength
(S1), kPa
(dry)
Average
Tensile
Strength
(S2), kPa
(wet)
TSR
(%)
9.5
0
577.1 443.1
586 467 79.7 550.2 473.5
630.3 484.2
14
564.1 498.2
615 493 80.1 654.7 509.6
627.0 470.7
17
515.8 430.7
551 457 82.9 580.2 486.1
556.8 453.9
20
585.0 438.4
566 452 80.0 556.1 489.9
555.8 428.7
12.5
0
812.6 609.3
815 638 78.3 785.5 673.8
848.2 631.9
10
728.8 737.4
751 631 84.0 782.6 577.8
742.3 579.0
13
785.1 554.9
694 583 84.0 699.5 581.1
597.2 612.9
17
751.7 492.6
660 528 79.9 649.3 490.2
580.3 600.0
19
0
723.6 615.8
733 606 82.7 764.0 612.4
710.9 590.6
4
585.3 469.4
623 506 81.2 603.8 599.7
678.8 447.9
7
630.1 551.7
658 552 84.0 710.9 559.4
631.8 546.2
10
766.8 576.8
673 559 83.0 571.5 584.2
679.8 514.6
86
0% 14% 17% 20%
0
200
400
600
ITS
, kP
a
Unconditioned
Conditioned
WPB by weight of OBC (%)
(a)
0% 10% 13% 17%
0
200
400
600
800
ITS
, k
Pa
Unconditioned
Conditioned
WPB by weight of OBC (%)
87
(b)
0% 4% 7% 10%
0
200
400
600
800
ITS
, kP
a
Unconditioned
Conditioned
WPB by weight of OBC (%)
(c)
ITS Test results of (a) 9.5mm, (b)12.5mm and (c) 19mm NMAS
0% 14% 17% 20%
0
10
20
30
40
50
60
70
80
90
100
TS
R (
%)
WPB by weight of OBC (%)
(a)
88
0% 10% 13% 17%
0
10
20
30
40
50
60
70
80
90
100
TS
R (
%)
WPB by weight of OBC (%)
(b)
0% 4% 7% 10%
0
10
20
30
40
50
60
70
80
90
100
TS
R (
%)
WPB by weight of OBC (%)
(c)
TSR Test results for (a) 9.5mm, (b)12.5mm and (c) 19mm NMAS
89
APPENDIX H: SPSS SOFTWARE OUTPUTS
ANOVA Analysis on Tests of b/n subject’s effects
i. Dependent variable: Bulk density
Source
Type III Sum
of Squares df Mean Square F Sig.
WPB .022 5 .004 26.798 .000
NMAS .031 2 .015 94.264 .000
WPB * NMAS .005 10 .000 2.906 .009
ii. Dependent variable: Flow
Source
Type III Sum
of Squares df Mean Square F Sig.
WPB 1.124 5 .225 2.183 .078
NMAS 3.368 2 1.684 16.354 .000
WPB * NMAS 2.190 10 .219 2.127 .048
iii. Dependent variable: Stability
Source
Type III Sum
of Squares df Mean Square F Sig.
WPB 5.429 5 1.086 2.788 .031
NMAS 1.604 2 .802 2.060 .142
WPB * NMAS 2.027 10 .203 .520 .864
iv. Dependent variable: Air Void
Source
Type III Sum
of Squares df Mean Square F Sig.
WPB 12.772 5 2.554 10.039 .000
NMAS 32.645 2 16.322 64.149 .000
WPB * NMAS 8.137 10 .814 3.198 .005
v. Dependent variable: VMA
Source
Type III Sum
of Squares df
Mean
Square F Sig.
WPB 28.099 5 5.620 26.504 .000
90
NMAS 79.948 2 39.974 188.523 .000
WPB * NMAS 6.334 10 .633 2.987 .008
vi. Dependent variable: VFA
Source
Type III Sum
of Squares df Mean Square F Sig.
WPB 214.074 5 42.815 7.218 .000
NMAS 1532.095 2 766.047 129.141 .000
WPB * NMAS 209.752 10 20.975 3.536 .002
Post Hoc, Tukey HSD Multiple Comparisons Tests for WPB and NMAS
i. Dependent variable: Bulk density
(I)
WPB
(J)
WPB
Mean
Difference
(I-J) Std. Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
0% 6% -.00356 .006001 .991 -.02161 .01450
9% .01856* .006001 .041 .00050 .03661
12% .02756* .006001 .001 .00950 .04561
15% .04200* .006001 .000 .02395 .06005
18% .05089* .006001 .000 .03284 .06894
6% 0% .00356 .006001 .991 -.01450 .02161
9% .02211* .006001 .009 .00406 .04016
12% .03111* .006001 .000 .01306 .04916
15% .04556* .006001 .000 .02750 .06361
18% .05444* .006001 .000 .03639 .07250
9% 0% -.01856* .006001 .041 -.03661 -.00050
6% -.02211* .006001 .009 -.04016 -.00406
12% .00900 .006001 .667 -.00905 .02705
15% .02344* .006001 .005 .00539 .04150
18% .03233* .006001 .000 .01428 .05039
12% 0% -.02756* .006001 .001 -.04561 -.00950
6% -.03111* .006001 .000 -.04916 -.01306
9% -.00900 .006001 .667 -.02705 .00905
15% .01444 .006001 .181 -.00361 .03250
18% .02333* .006001 .005 .00528 .04139
15% 0% -.04200* .006001 .000 -.06005 -.02395
6% -.04556* .006001 .000 -.06361 -.02750
9% -.02344* .006001 .005 -.04150 -.00539
12% -.01444 .006001 .181 -.03250 .00361
91
18% .00889 .006001 .678 -.00916 .02694
18% 0% -.05089* .006001 .000 -.06894 -.03284
6% -.05444* .006001 .000 -.07250 -.03639
9% -.03233* .006001 .000 -.05039 -.01428
12% -.02333* .006001 .005 -.04139 -.00528
15% -.00889 .006001 .678 -.02694 .00916
(I)
NMAS
(J)
NMAS
Mean
Difference
(I-J) Std. Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
9.5 12.5 -.05817* .004243 .000 -.06854 -.04780
19 -.03194* .004243 .000 -.04232 -.02157
12.5 9.5 .05817* .004243 .000 .04780 .06854
19 .02622* .004243 .000 .01585 .03659
19 9.5 .03194* .004243 .000 .02157 .04232
12.5 -.02622* .004243 .000 -.03659 -.01585
*. The mean difference is significant at the .05 level.
ii. Dependent variable: Flow
(I)
WPB
(J)
WPB
Mean
Difference
(I-J) Std. Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
0% 6% .089 .1513 .991 -.366 .544
9% .200 .1513 .771 -.255 .655
12% .333 .1513 .261 -.122 .788
15% .278 .1513 .456 -.177 .733
18% -.067 .1513 .998 -.522 .388
6% 0% -.089 .1513 .991 -.544 .366
9% .111 .1513 .976 -.344 .566
12% .244 .1513 .594 -.211 .700
15% .189 .1513 .810 -.266 .644
18% -.156 .1513 .905 -.611 .300
9% 0% -.200 .1513 .771 -.655 .255
6% -.111 .1513 .976 -.566 .344
12% .133 .1513 .949 -.322 .588
15% .078 .1513 .995 -.377 .533
18% -.267 .1513 .501 -.722 .188
12% 0% -.333 .1513 .261 -.788 .122
6% -.244 .1513 .594 -.700 .211
9% -.133 .1513 .949 -.588 .322
15% -.056 .1513 .999 -.511 .400
92
18% -.400 .1513 .113 -.855 .055
15% 0% -.278 .1513 .456 -.733 .177
6% -.189 .1513 .810 -.644 .266
9% -.078 .1513 .995 -.533 .377
12% .056 .1513 .999 -.400 .511
18% -.344 .1513 .230 -.800 .111
18% 0% .067 .1513 .998 -.388 .522
6% .156 .1513 .905 -.300 .611
9% .267 .1513 .501 -.188 .722
12% .400 .1513 .113 -.055 .855
15% .344 .1513 .230 -.111 .800
(I)
NMAS
(J)
NMAS
Mean
Difference
(I-J)
Std.
Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
9.5 12.5 -.594* .1070 .000 -.856 -.333
19 -.172 .1070 .254 -.434 .089
12.5 9.5 .594* .1070 .000 .333 .856
19 .422* .1070 .001 .161 .684
19 9.5 .172 .1070 .254 -.089 .434
12.5 -.422* .1070 .001 -.684 -.161
*. The mean difference is significant at the .05 level.
iii. Dependent variable: Stability
(I)
WPB
(J)
WPB
Mean
Difference
(I-J) Std. Error Sig.
95% Confidence
Interval
Lower
Bound
Upper
Bound
0% 6% -.311 .2942 .895 -1.196 .574
9% -.422 .2942 .706 -1.307 .463
12% -.756 .2942 .132 -1.641 .130
15% -.856 .2942 .063 -1.741 .030
18% -.856 .2942 .063 -1.741 .030
6% 0% .311 .2942 .895 -.574 1.196
9% -.111 .2942 .999 -.996 .774
12% -.444 .2942 .660 -1.330 .441
15% -.544 .2942 .448 -1.430 .341
18% -.544 .2942 .448 -1.430 .341
9% 0% .422 .2942 .706 -.463 1.307
6% .111 .2942 .999 -.774 .996
12% -.333 .2942 .864 -1.218 .552
15% -.433 .2942 .683 -1.318 .452
93
18% -.433 .2942 .683 -1.318 .452
12% 0% .756 .2942 .132 -.130 1.641
6% .444 .2942 .660 -.441 1.330
9% .333 .2942 .864 -.552 1.218
15% -.100 .2942 .999 -.985 .785
18% -.100 .2942 .999 -.985 .785
15% 0% .856 .2942 .063 -.030 1.741
6% .544 .2942 .448 -.341 1.430
9% .433 .2942 .683 -.452 1.318
12% .100 .2942 .999 -.785 .985
18% .000 .2942 1.000 -.885 .885
18% 0% .856 .2942 .063 -.030 1.741
6% .544 .2942 .448 -.341 1.430
9% .433 .2942 .683 -.452 1.318
12% .100 .2942 .999 -.785 .985
15% .000 .2942 1.000 -.885 .885
(I)
NMAS
(J)
NMAS
Mean
Difference
(I-J) Std. Error Sig.
95% Confidence
Interval
Lower
Bound
Upper
Bound
9.5 12.5 .289 .2080 .357 -.220 .797
19 -.122 .2080 .828 -.631 .386
12.5 9.5 -.289 .2080 .357 -.797 .220
19 -.411 .2080 .133 -.920 .097
19 9.5 .122 .2080 .828 -.386 .631
12.5 .411 .2080 .133 -.097 .920
iv. Dependent variable: Air Void
(I)
WPB
(J)
WPB
Mean
Difference
(I-J) Std. Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
0% 6% .533 .2378 .244 -.182 1.249
9% -.189 .2378 .967 -.904 .527
12% -.367 .2378 .640 -1.082 .349
15% -.767* .2378 .030 -1.482 -.051
18% -.933* .2378 .005 -1.649 -.218
6% 0% -.533 .2378 .244 -1.249 .182
9% -.722* .2378 .047 -1.438 -.007
12% -.900* .2378 .007 -1.615 -.185
15% -1.300* .2378 .000 -2.015 -.585
18% -1.467* .2378 .000 -2.182 -.751
94
9% 0% .189 .2378 .967 -.527 .904
6% .722* .2378 .047 .007 1.438
12% -.178 .2378 .974 -.893 .538
15% -.578 .2378 .173 -1.293 .138
18% -.744* .2378 .037 -1.460 -.029
12% 0% .367 .2378 .640 -.349 1.082
6% .900* .2378 .007 .185 1.615
9% .178 .2378 .974 -.538 .893
15% -.400 .2378 .552 -1.115 .315
18% -.567 .2378 .189 -1.282 .149
15% 0% .767* .2378 .030 .051 1.482
6% 1.300* .2378 .000 .585 2.015
9% .578 .2378 .173 -.138 1.293
12% .400 .2378 .552 -.315 1.115
18% -.167 .2378 .981 -.882 .549
18% 0% .933* .2378 .005 .218 1.649
6% 1.467* .2378 .000 .751 2.182
9% .744* .2378 .037 .029 1.460
12% .567 .2378 .189 -.149 1.282
15% .167 .2378 .981 -.549 .882
(I)
NMAS
(J)
NMAS
Mean
Difference
(I-J)
Std.
Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
9.5 12.5 1.117* .1681 .000 .706 1.528
19 -.778* .1681 .000 -1.189 -.367
12.5 9.5 -1.117* .1681 .000 -1.528 -.706
19 -1.894* .1681 .000 -2.305 -1.483
19 9.5 .778* .1681 .000 .367 1.189
12.5 1.894* .1681 .000 1.483 2.305
*. The mean difference is significant at the .05 level.
v. Dependent variable: VMA
(I)
WPB
(J)
WPB
Mean
Difference
(I-J) Std. Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
0% 6% .122 .2171 .993 -.531 .775
9% -.678* .2171 .038 -1.331 -.025
12% -.989* .2171 .001 -1.642 -.336
15% -1.533* .2171 .000 -2.186 -.880
18% -1.822* .2171 .000 -2.475 -1.169
6% 0% -.122 .2171 .993 -.775 .531
95
9% -.800* .2171 .009 -1.453 -.147
12% -1.111* .2171 .000 -1.764 -.458
15% -1.656* .2171 .000 -2.309 -1.002
18% -1.944* .2171 .000 -2.598 -1.291
9% 0% .678* .2171 .038 .025 1.331
6% .800* .2171 .009 .147 1.453
12% -.311 .2171 .707 -.964 .342
15% -.856* .2171 .004 -1.509 -.202
18% -1.144* .2171 .000 -1.798 -.491
12% 0% .989* .2171 .001 .336 1.642
6% 1.111* .2171 .000 .458 1.764
9% .311 .2171 .707 -.342 .964
15% -.544 .2171 .149 -1.198 .109
18% -.833* .2171 .006 -1.486 -.180
15% 0% 1.533* .2171 .000 .880 2.186
6% 1.656* .2171 .000 1.002 2.309
9% .856* .2171 .004 .202 1.509
12% .544 .2171 .149 -.109 1.198
18% -.289 .2171 .766 -.942 .364
18% 0% 1.822* .2171 .000 1.169 2.475
6% 1.944* .2171 .000 1.291 2.598
9% 1.144* .2171 .000 .491 1.798
12% .833* .2171 .006 .180 1.486
15% .289 .2171 .766 -.364 .942
(I)
NMAS
(J)
NMAS
Mean
Difference
(I-J)
Std.
Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
9.5 12.5 2.678* .1535 .000 2.303 3.053
19 2.472* .1535 .000 2.097 2.847
12.5 9.5 -2.678* .1535 .000 -3.053 -2.303
19 -.206 .1535 .383 -.581 .170
19 9.5 -2.472* .1535 .000 -2.847 -2.097
12.5 .206 .1535 .383 -.170 .581
*. The mean difference is significant at the .05 level.
vi. Dependent variable: VMA
(I)
WPB
(J)
WPB
Mean
Difference
(I-J) Std. Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
0% 6% -3.711* 1.1481 .029 -7.165 -.257
96
9% -.033 1.1481 1.000 -3.488 3.421
12% .478 1.1481 .998 -2.976 3.932
15% 2.011 1.1481 .508 -1.443 5.465
18% 2.444 1.1481 .296 -1.010 5.899
6% 0% 3.711* 1.1481 .029 .257 7.165
9% 3.678* 1.1481 .031 .224 7.132
12% 4.189* 1.1481 .010 .735 7.643
15% 5.722* 1.1481 .000 2.268 9.176
18% 6.156* 1.1481 .000 2.701 9.610
9% 0% .033 1.1481 1.000 -3.421 3.488
6% -3.678* 1.1481 .031 -7.132 -.224
12% .511 1.1481 .998 -2.943 3.965
15% 2.044 1.1481 .490 -1.410 5.499
18% 2.478 1.1481 .282 -.976 5.932
12% 0% -.478 1.1481 .998 -3.932 2.976
6% -4.189* 1.1481 .010 -7.643 -.735
9% -.511 1.1481 .998 -3.965 2.943
15% 1.533 1.1481 .764 -1.921 4.988
18% 1.967 1.1481 .533 -1.488 5.421
15% 0% -2.011 1.1481 .508 -5.465 1.443
6% -5.722* 1.1481 .000 -9.176 -2.268
9% -2.044 1.1481 .490 -5.499 1.410
12% -1.533 1.1481 .764 -4.988 1.921
18% .433 1.1481 .999 -3.021 3.888
18% 0% -2.444 1.1481 .296 -5.899 1.010
6% -6.156* 1.1481 .000 -9.610 -2.701
9% -2.478 1.1481 .282 -5.932 .976
12% -1.967 1.1481 .533 -5.421 1.488
15% -.433 1.1481 .999 -3.888 3.021
(I)
NMAS
(J)
NMAS
Mean
Difference
(I-J)
Std.
Error Sig.
95% Confidence Interval
Lower
Bound
Upper
Bound
9.5 12.5 -2.756* .8118 .005 -4.740 -.771
19 9.667* .8118 .000 7.682 11.651
12.5 9.5 2.756* .8118 .005 .771 4.740
19 12.422* .8118 .000 10.438 14.407
19 9.5 -9.667* .8118 .000 -11.651 -7.682
12.5 -12.422* .8118 .000 -14.407 -10.438
*. The mean difference is significant at the .05 level.
97
APPENDIX I: PHOTOS
Aggregate sample collection preparation (from CCECC quarry source around Yibab)
98
Aggregate quality test
FTIR Experimental Setup DSC Experimental Setup
99
Marshall specimen preparation for respective NMAS
Measuring sample in air Measuring sample in water
Water bath to maintain testing temperature
100
Addation of WPB before and after mixing with hot aggregate
Specimens for conditioned and Unconditioned ITS test
ITS conditioning of the specimens in water bath Maintaining testing temp. for
unconditioned test
101
Marshall stability & flow test ITS test
ITS unconditioned sample before test ITS conditioned sample after test