BEHAVIOUR OF RUBBERIZED ASPHALT MIXTURE SUBJECTED TO

THERMAL LOADING

DLER HASSAN HUSSEIN

A project report submitted in partial fulfilment of the

requirements for the award of degree of

Master of Engineering (Civil – Transportation and Highway)

Faculty of Civil Engineering

Universiti Teknologi Malaysia

JANUARY 2015

iv

To my beloved Father and Mother

who support me spiritually throughout my life

To DIMAN,

my amazing wife,

whose sacrificial care for me and our daughters

made it possible for me to complete this work

To my daughters,

ZHWAN and YARAN

who are indeed a treasure from Allah

v

ACKNOWLEDGEMENT

In the Name of Allah, the Most Gracious, the Most Merciful

Praise and glory be to Almighty Allah for his blessings and giving me the

health and power to complete this work.

Foremost, I would like to express my special appreciation and thanks for the

continuous support of my supervisor Dr. Norhidayah Abdul Hassan. There are no

proper words to convey my deep gratitude and respect for the useful comments,

remarks and engagement through the learning process of this master project. Her

patience, motivation, eagerness, and knowledge have inspired me to become an

independent and helped me realize the power of critical reasoning. I am very

fortunate to have met such a good supervisor in UTM. Really, this project would

never have been completed (as we wish) without her assistance and support. I still

remember her advice, is to produce a piece of work, that not only to fulfil the grade

but something that I can be proud of.

A special thanks to my parents and my father and mother in-law, your prayers

for me was what sustained me thus far. I am extremely grateful to my lovely wife

and my daughters for their patient and continued support and encouragement

throughout the study period. I would also like to thank my brothers and sisters and

in-laws for their unconditional trust and prayers. Special thanks are also extended to

the technicians of Transportation Laboratory in UTM, particularly (Mr Sahak) who

afforded his precious time during the weekends to open the lab for me and tolerate

until I finished my lab works.

Finally, I would express my gratitude to Kurdistan Regional Government for

supporting me to have the opportunity to get higher degree in UTM-Malaysia.

vi

ABSTRACT

This study investigated the behaviour of dry mixed rubberised asphalt

mixture subjected to permanent deformation under high temperature variation.

Crumb rubber, obtained from recycled scrap tyres was used as an aggregate

replacement within the asphalt mixture as it could potentially provide greater elastic

recovery to the mixture. The elements of natural and synthetic rubber within the

scrap tyres have been identified to improve the thermal stability of the tyre

compound and provide wider working temperature range. Therefore, to use the

crumb rubber as a modifier in asphalt mixture could possibly improve the properties

of asphalt mixture at various service temperatures and consequently, improve the

resistance against permanent deformation. Additionally, this could provide an

alternative in recycling the scrap tyres as non-decaying waste material. In this study,

a mixture of Asphaltic Concrete of AC14 (dense graded with nominal maximum

aggregate size 14 mm) was modified with 1, 2 and 3% of crumb rubber (coarse size,

5 mm) from the total weight of aggregate using dry process method. The properties

of the rubberised mixtures were compared to the control mixture (with no rubber).

Samples were prepared using Marshall Compactor and tested under Resilient

Modulus at 25 and 40ºC to measure the material stiffness. In addition, Dynamic

Creep Test was conducted to determine the permanent deformation at four

temperature conditions; 25, 40, 50, and 60°C. The analysis was focused on the effect

of adding crumb rubber in asphalt mixture in terms of accumulated permanent strain

under the influence of temperature variation. Based on this study, it was observed

that the susceptibility of asphalt mixture to high temperature was reduced by the

crumb rubber modification.

vii

ABSTRAK

Kajian ini telah dijalankan untuk mengenalpasti sifat campuran asfalt kering

dengan campuran getah yang tertakluk kepada perubahan bentuk kekal dengan

variasi suhu tinggi. Getah remah, „Crumb Rubber‟ yang diperolehi daripada tayar

sekerap yang dikitar semula telah digunakan sebagai pengganti agregat dalam

campuran asfalt kerana ia boleh memberikan kebolehan elastik yang lebih tinggi

kepada campuran. Unsur-unsur getah asli dan tiruan dalam tayar sekerap telah

dikenal pasti dapat meningkatkan kestabilan terma dalam kompaun tayar dan

menyediakan julat suhu kerja yang lebih luas. Oleh itu, penggunaan Getah Remah

sebagai pengubahsuai dalam campuran asfalt boleh meningkatkan sifat-sifat

campuran asfalt pada pelbagai julat suhu, justeru meningkatkan rintangan terhadap

perubahan bentuk kekal. Tambahan lagi, penggunaan Getah Remah dalam kajian ini

boleh memberikan alternatif dalam mengitar semula tayar sekerap yang sedia ada

dari bahan buangan tidak mereput. Dalam kajian ini, campuran konkrit asfalt

daripada AC14 (bergred tumpat dengan saiz nominal agregat maksimum 14 mm)

telah diubah suai dengan 1, 2 dan 3% daripada Getah Remah (saiz kasar, 5 mm) dari

jumlah berat agregat menggunakan kaedah proses kering. Sifat-sifat campuran Getah

Remah dibandingkan dengan campuran kawalan (tanpa getah). Sampel telah

disediakan dengan menggunakan Marshall Compactor dan diuji di bawah „Resilient

Modulus‟ pada suhu 25 dan 40ºC untuk mengukur kekukuhan bahan. Di samping itu,

ujian „Dinamik Creep‟ telah dijalankan untuk menentukan perubahan bentuk kekal

pada empat keadaan suhu; 25, 40, 50, dan 60°C. Analisis ini telah memberi tumpuan

kepada kesan penambahan Getah Remah dalam campuran asfalt dari aspek

ketegangan tetap terkumpul „permanent strain‟ hasil daripada pengaruh perubahan

suhu. Berdasarkan kajian ini, telah didapati bahawa pengaruh suhu yang tinggi

kepada campuran asphalt telah dikurangkan oleh pengubahsuaian Getah Remah

tersebut.

viii

TABLE OF CONTENTS

CHAPTER TITLE PAGE

DECLARATION ii

ACKNOWLEDGEMENT iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES x

LIST OF FIGURES xi

LIST OF ABBREVIATIONS AND SYMBOLS xiv

LIST OF APPENDICES xv

1 INTRODUCTION

1.1 Introduction 1

1.2 Problem Statement 3

1.3 Aim and Objectives of Study 4

1.4 Scope of Study 5

1.5 Significance of Knowledge 5

2 LITERATURE REVIEW

2.1 Introduction 7

2.2 Thermal Effects on Asphalt Pavement 8

2.3 Permanent Deformation in Asphalt Pavement 11

2.4 Resilient Modulus 15

2.5 Creep and Recovery Behaviour 16

2.6 Asphalt Mixture Materials 18

2.6.1 Bituminous Binder 19

2.6.2 Aggregate and Gradation 22

2.6.3 Air voids in Mixture 24

ix

2.7 Crumb Rubber Modifier 25

2.7.1 Waste tires in civil engineering applications 25

2.7.2 Recovered Rubber: Types and Particle Size 27

2.7.3 Crumb Rubber: Properties and Production 28

2.7.4 Crumb Rubber : Composition and Physical

Properties 30

2.8 Rubberized Asphalt Mixture (RAM) 34

2.8.1 Background 34

2.8.2 Wet Process 35

2.8.3 Dry Process 36

2.8.4 Benefits and limitation of RAM 37

2.9 Modification Concept of Dry Process 38

2.10 Dry Mixed RAM Technology 40

3 METHODOLOGY

3.1 Introduction 43

3.2 Operational Framework 44

3.3 1st Stage: Asphalt Mixture Design 45

3.3.1 Materials 45

3.3.1.1 Aggregate 45

3.3.1.2 Bitumen 46

3.3.1.3 Crumb Rubber 47

3.3.2 Sieve Analysis 47

3.3.3 Aggregate Gradation 50

3.3.3.1 Aggregate Replacement with Crumb

Rubber 51

3.3.3.2 RAM Aggregate Gradation 53

3.3.3.3 Specific Gravity 53

3.3.4 Marshall Mix Design 57

3.3.4.1 Conventional Asphalt Mixture 57

3.3.4.2 Rubberized Asphalt Mixture 58

3.3.5 Marshall Mix Design Procedures 59

3.3.5.1 Apparatus 60

3.3.5.2 Procedures 61

3.3.6 Theoretical Maximum Density 64

3.3.6.1 Apparatus 65

3.3.6.2 Procedures 65

x

3.3.7 Bulk Specific Gravity 67

3.3.7.1 Apparatus 67

3.3.7.2 Procedures 68

3.3.8 Flow and Stability Test 70

3.3.8.1 Apparatus 70

3.3.8.2 Procedures 71

3.3.9 Determination of Optimum Bitumen Content

(OBC) 73

3.4 2nd

Stage: Resilient Modulus Test 74

3.4.1 Apparatus 74

3.4.2 Procedures 77

3.5 3rd

Stage: Dynamic Creep Test 80

3.5.1 Apparatus 80

3.5.2 Procedures 82

4 RESULTS AND DISCUSSIONS

4.1 Introduction 84

4.2 Asphalt Mixture Design 85

4.2.1 Material Properties 85

4.2.2 Aggregate Gradation 86

4.2.3 Marshall Mix Method Test Analysis 90

4.2.4 Volumetric Analysis of Asphalt Mixture

Samples 93

4.2.5 Determination of Optimum Bitumen Content

(OBC) 95

4.3 Sample Preparation for Test Performance 97

4.4 Resilient Modulus 98

4.5 Permanent Deformation 100

5 CONCLUSIONS AND RECOMMENDATIONS

5.1 Conclusions 112

5.2 Recommendations 114

REFERENCES 115

APPENDICES A - J 119

xi

LIST OF TABLES

TABLE NO. TITLE PAGE

2.1 Elementary analysis of the bituminous materials 20

2.2 Aggregate characteristics effect on rutting of

asphalt mixture

24

2.3 Comparison of passenger car and truck in the EU 31

2.4 Comparison of passenger car and truck (Rubber

Manufacturer Association, USA)

31

2.5 Effect of different temperature on rubber

properties

32

3.1 Gradation Limit for Asphalt mixture AC 14 51

3.2 Design Bitumen Content 57

3.3 Test and Analysis Parameter 58

3.4 Total number of samples for Marshall Mix Design 59

4.1 Bitumen properties 85

4.2 Aggregate size 5 mm properties 86

4.3 Gradation Limit for Asphalt mixture AC14 for Control

(0%CRM) mixture

87

4.4 Volumetric aggregate replacement with CR 88

4.5 Gradation Limit for Rubberized Asphalt mixture AC14

(1, 2 and 3%CRM) mixture

88

4.6 Optimum Bitumen Content (OBC) for all mixtures 96

4.7 Marshall Mix Design Method requirements 96

xii

LIST OF FIGURES

FIGURE NO. TITLE PAGE

2.1 Highest pavement temperatures vs. highest air

temperature

9

2.2 Schematic showing three main regions in the

relationship between total permanent strains and

loading cycles curve

14

2.3 Idealized responses of elastic, viscous and

viscoelastic material under constant stress loading

22

2.4 Aggregate mixture gradation 23

2.5 Crumb Rubber production methods 30

2.6 Wet Process Method 36

2.7 Dry Process Method 37

2.8 Illustration of elastic behaviour of rubber particles 39

3.1 Operational framework of the laboratory work 44

3.2 AC 14 Aggregate Mix, Retaining on Various Sieve

Sizes (1200 g)

46

3.3 Bitumen Pen 60/70 sample 46

3.4 Crumb Rubber Modifier (CRM) 47

3.5 Mechanical Sieve Shaker with different sieve sizes 48

3.6 Separating aggregates according to appropriate size

from AC 14

49

3.7 Washing aggregate to remove the dust 50

3.8 Aggregate gradations for AC14 51

3.9 CR and Aggregate Comparison by Volume and

Mass (for 3%CRM)

52

xiii

3.10 Aggregate samples in the immersed glass flask 54

3.11 Weighing filled (with distilled water and aggregate

sample) glass flask

56

3.12 Drying process for aggregate sample 56

3.13 Heating process in Marshall Mix method 62

3.14 Mixing process in Marshall Mix method 63

3.15 Compacting and extracting process in Marshall Mix

method

63

3.16 All samples were used for Marshall Mix method 64

3.17 Loose Asphalt Mixture sample 66

3.18 Vacuum Apparatus for TMD test 66

3.19 Vessel weighted in water and in air 67

3.20 Balance with wire basket in water bath 68

3.21 Weighting Marshall sample in air and water 69

3.22 Water bath 71

3.23 Marshall Machine 71

3.24 UTM Machine (Resilient Modulus Tools Installed) 76

3.25 UTM Machine-Resilient Modulus components 76

3.26 Resilient Modulus components 77

3.27 Resilient Modulus Test Software Result Display 79

3.28 UTM Machine (Dynamic Creep Tools Installed) 81

3.29 UTM Machine-Dynamic Creep Test 81

3.30 Sample under Dynamic Creep Test 82

3.31 Dynamic Creep Test Software Result Display 83

4.1 Designed percentage of each material by volume 89

4.2 Designed percentage of each material by mass 89

4.3 Marshall Samples 98

4.4 Resilient Modulus results at 25°C 99

4.5 Resilient Modulus results at 40°C 100

4.6 Accumulative Permanent Strains vs. Loading Cycles for

Control Mixture (0%CRM) @ 25, 40, 50 and 60°C

103

4.7 Accumulative Permanent Strains vs. Loading

Cycles for RAM (1%CRM) @ 25, 40, 50 and 60°C

103

xiv

4.8 Accumulative Permanent Strains vs. Loading

Cycles for RAM (2%CRM) @ 25, 40, 50 and 60°C

104

4.9 Accumulative Permanent Strains vs. Loading

Cycles for RAM (3%CRM) @ 25, 40, 50 and 60°C

104

4.10 Accumulative Permanent Strains vs. Loading

Cycles @ 25°C

105

4.11 Accumulative Permanent Strains vs. Loading

Cycles @ 40°C

105

4.12 Accumulative Permanent Strains vs. Loading

Cycles @ 50°C

106

4.13 Accumulative Permanent Strains vs. Loading

Cycles @ 60°C

106

4.14 Simulation of the sample shapes after Creep test at

different temperature (Increment explanation)

107

4.15 Loading cycle stations (For comparison between

strain increments at different temperature)

108

4.16 Accumulative Strain Increment Rate @ 40ºC 108

4.17 Accumulative Strain Increment Rate @ 50ºC 109

4.18 Accumulative Strain Increment Rate @ 60ºC 109

4.19 Creep Modulus for control mixture and RAMs

(1%CRM, 2%CRM and 3%CRM) at 1000 load

cycles under various temperature

111

xv

LIST OF ABBREVIATIONS AND SYMBOLS

AASHTO - American Association of State Highway and Transportation

AC - Asphaltic Concrete

ASTM - American Society of Testing and Materials

BS - British Standards

CRM - Crumb Rubber Modifier

En - Creep modulus

F - Flow

Gmb - Bulk specific gravity of compacted mix

Gmm - Theoretical maximum density

Gse - Effective specific gravity of total aggregate

HMA - Hot Mix Asphalt

JKR - Jabatan Kerja Raya

LVDT - Linear Variable Differential Transformer

Mr - Resilient Modulus

OBC - Optimum Bitumen Content

RAM - Rubberized Asphalt Mixture

S - Stability

SSD - Saturated Surface Dry

TMD - Theoretical Maximum Density

UTM - Universal Testing Machine

VFB - Voids Filled with Bitumen

VMA - Voids in Mineral Aggregate

VTM - Void in Total Mix

Ɛ - Accumulated strain

σ - Compressive axial stress

xvi

LIST OF APPENDICES

APPENDIX TITLE PAGE

A Specific Gravity for Aggregate Size (5 mm) 119

B Aggregate Gradation (AC14) Graphs 121

C Theoretical Maximum Density 123

D Marshall Test Results 128

E Marshall Parameters vs. Bitumen Content Graphs 133

F Marshall Volumetric Parameter Results (VTM Check) 138

G Resilient Modulus Test Results 143

H Dynamic Creep Test Results 146

I Permanent Strain and Increment Rate 149

J Preparing, Testing and Trimming Samples 151

CHAPTER 1

INTRODUCTION

1.1 Introduction

Asphalt mixtures are complex heterogeneous materials consists of bitumen,

aggregate and air voids. The interactions between these components resist the loads

from the traffic to underneath layers and their properties determine the ability of the

road layers to withstand the loads and prevent the failure (Abdul Hassan and Rosli,

2012). At high temperatures, the bitumen tends to flow easily, and behaves like a

viscous liquid. This could lead to the loss of internal friction between the aggregate

particles, consequently make the repeated loading be supported by the asphalt binder

rather than the aggregate structure, resulting in the permanent deformation in asphalt

mixtures (Huang et al., 2012). On the other hand, asphalt mixture according to their

components, is a temperature sensitive material, where the properties close to elastic

material at a lower temperature and close to viscous material at a higher temperature.

Its viscoelastic property has a close relationship to rutting, cracking, fatigue

behaviour, and other distresses of asphalt pavement (Peilong Li et al., 2013).

Therefore, it is very important to find out ways to delay the asphalt pavement

deterioration experienced by the conventional asphalt mixture and increase pavement

service life.

Various researchers reported that using additives such as different type of

polymers and fibres to modify asphalt mixture could be a solution to delay

2

deterioration of asphalt pavement (Moghaddam et al., 2011). The addition of Crumb

Rubber Modifier (CRM) as polymer additives in asphalt mixtures has increased

significantly in past years around the world, especially in the USA. Several of the

roads have been reported to be in good condition after several years in service in

comparison to conventional mixtures (Wong and Wong, 2007). Previous studies

have demonstrated that CRM binders produce pavements with good mechanical

behaviour. They offer improved resistance to rutting, better resistance to low

temperature cracking, reduced fatigue cracking and temperature susceptibility,

decreased traffic noise and maintenance costs, and prolonged pavement life. These

pavements also save energy and natural resources by making use of waste products.

Because of these advantages, CRM asphalt mixtures are increasingly used as a green

material in the highway pavement construction industry in many countries

(Rodríguez et al., 2014).

Crumb rubber modified materials are mainly applied via two techniques in

asphalt pavement. One is the wet process, in which the crumb rubber is used as a

modifier in bitumen, and the other is the dry process, in which the ground crumb

rubber is directly mixed with aggregate prior to mixing it with bitumen. Although,

the wet process has been used widely for its excellent performance in comparison to

dry process, still the last has own distinct advantages as it can be added directly to

the aggregate, that means the process is simpler and the amount of crumb rubber

recycled is greater than those used in wet process. In this study, the properties of the

rubberized asphalt mixture using dry process under permanent deformation mode

were investigated under the influence of high temperature. Different percentages of

CRM modified asphalt mixture were evaluated and compared with the conventional

asphalt mixture.

3

1.2 Problem Statement

Allocating design period and service quality for any highway construction

project are essentially rely on the asphalt mixture component that consist of bitumen,

aggregate and air voids. Unfortunately, with the steady increase in the traffic

intensity and high axle load with the significant variation in daily and seasonal

temperature asphalt mixtures a typical visco-elastic material damaged at different

environmental condition particularly at high temperature. This is because; under this

condition the viscosity of the asphalt binder will be very low and thus reduce the

internal friction between the aggregate particles, leading to the permanent

deformation.

The phenomenon of permanent deformation in asphalt pavements has a major

impact on the pavement performance throughout its life. It will not only reduce the

service life, but it may also affect the vehicle handling manoeuvres, which can be

hazardous to the road users. Therefore, it is a demand for improving the properties of

the asphalt mixture by modifying the conventional asphalt mixtures to enhance the

mixture properties. One of the modification methods is to introduce recycled material

such as crumb rubber (obtained from scrap tires) as aggregate replacement within the

mixture using dry process. Previous research has established that adding CRM could

improve asphalt mixture resistant against permanent deformation and fatigue cracks

(Hamed, 2010; Peilong Li et al., 2013; Moghaddam et al., 2011).

In addition, by modifying asphalt mixture with CRM using dry process could

result of better performance at both high and low temperatures (Cao, 2007).

Therefore, this study was carried out to investigate the effect of CRM on the asphalt

mixture characteristics in term of its resistance against permanent deformation under

temperature variation. Moreover, the rubber composition within the tires consists of

natural and synthetic rubber where these materials are identified to improve the

thermal stability of the tire compound, making it ideal for anti-vibration applications

and use in large tires where excessive heat build-up could be disastrous. For example

the natural rubber has a working temperature range of approximately -50oC to 100

oC.

4

Additionally, the properties of the compound also could provide greater elastic

recovery and excellent physical strength as well as resilience and high resistance to

tearing and abrasion.

1.3 Aim and Objectives of Study

The aim of this study is to investigate the mechanical properties of dry mixed

rubberized asphalt mixture under the temperature variation. The objectives are as

follows:

i) To determine the effect of different percentages of CRM on resilient modulus

of asphalt mixture.

ii) To determine the performance of rubberized asphalt mixture under permanent

deformation with the influence of temperature variation.

5

1.4 Scope of Study

In this study four mixture types were prepared namely control mixture

(Asphalt mixture with nominal maximum aggregate size, NMAS 14 mm-AC14

without rubber) and rubberized mixture with 1, 2 and 3% of crumb rubber (single

size of 5 mm) from the total weight of aggregate. AC 14 is a dense graded mixture

type according to JKR/SPJ/2008-S4. Marshall Mix design was used for fabricating

the compacted samples and determining the optimum bitumen content. Resilient

Modulus test was conducted at 25 and 40ºC, to measure the material stiffness. In

addition, the samples were tested under various temperature conditions to evaluate

the permanent deformation under high temperature using Dynamic Creep Test. The

samples were tested at four temperature conditions; 25, 40, 50, and 60°C. This range

of temperatures was intended to simulate a full hot season cycle of outdoor

temperature variations a pavement would experience. It should be noted that the

temperature variation in an asphalt pavement is significantly higher than the air

temperature. Therefore, the range of testing temperatures presented here reflects the

pavement temperatures, not the encompassing aboveground temperature.

1.5 Significance to Knowledge

Noticeable differences in the temperature degree in many countries influence

the asphalt mixture performance, causing a lot of distresses in the pavement.

Permanent deformation is one of the main distresses which normally occur in hot

climate area as a result of the repeated heavy axle load. The resistance of asphalt

mixtures against permanent deformation change with the influence of the

temperature fluctuation due to the asphalt temperature‟s susceptibility where it tends

to flow at high temperatures. As a result, each year millions of dollars are invested

for the construction and maintenance of roads. Therefore, to use an elastomer

polymer such as crumb rubber is expected to improve the stability of the asphalt

mixture at high and low temperature service. This is because some valuable

6

components within the crumb rubber might well contribute to the improvement of

bitumen properties as well as asphalt mixture. Additionally, this could provide an

alternative in recycling the scrap tires as non-decaying waste material. Previous

studies conducted on the asphalt mixture modified with crumb rubber, particularly

using wet process have proved that the rubber could reduce the temperature

susceptibility of the mixture and increase thermal cracking resistance (Rodríguez et

al., 2014). However, not much information can be found on the performance of dry

mixed rubberized asphalt mixture under the temperature variances. Therefore, this

study is very important in getting some data related to the temperature influence

upon the permanent deformation mode of dry mixed rubberized asphalt mixture.

REFERENCES

Abdul Hassan, N. (2012). Microstructural Characterisation of Rubber Modified

Asphalt Mixture. (Doctor of Philosophy), University of Nottingham.

Abdul Hassan, N., & Rosli, H. M. (2012). Application of X-ray Computed

Tomography for Air Voids and Damage Characterisation in Asphalt

Mixtures. JURUTERA, 20-23.

Ahari, A. S., Forough, S. A., Khodaii, A., & Nejad, F. M. (2013). Modeling the

Primary and Secondary Regions of Creep Curves for SBS-Modified Asphalt

Mixtures under Dry and Wet Conditions. Journal of Materials in Civil

Engineering, 26(5), 904-911.

Aloysius, T., & Napitupulu, R. (2013). Verification of Resilient Modulus Prediction

of Asphalt Mixtures. Paper presented at the Proceedings of the Eastern Asia

Society for Transportation Studies.

American Society for Testing and Materials (2005). Standard Test Method for

Penetration of Bituminous Materials, ASTM D 5. Philadelphia, USA.

American Society for Testing and Materials (2014). Standard Test Method for

Softening Point of Bitumen (Ring-and-Ball Apparatus), ASTM D 36. West

Conshohocken, PA.

American Society for Testing and Materials (2003). Standard Test Method for

Specific Gravity and Density of Semi-Solid Bituminous Materials

(Pycnometer Method), ASTM D 70. West Conshohocken, PA.

American Society for Testing and Materials (2006). Standard Test Method for Sieve

Analysis of Fine and Coarse Aggregates, ASTM C 136. West Conshohocken,

PA.

American Society for Testing and Materials (2000). Standard Test Method for

Theoretical Maximum Specific Gravity and Density of Bituminous Paving

Mixtures, ASTM D 2041. West Conshohocken, PA.

American Society for Testing and Materials (1995). Standard Test Method for

Indirect Tension test for Resilient Modulus of Bituminous Mixtures, ASTM

D 4123. West Conshohocken, PA.

116

Arshadi, A. (2013). Importance of Asphalt Binder Properties on Rut Resistance of

Asphalt Mixture. (Master of Science), University of Wisconsin-Madison.

Bai, F., Yang, X., & Zeng, G. (2014). Creep and recovery behavior characterization

of asphalt mixture in compression. Construction and building materials, 54,

504-511.

Bennert, T., Maher, A., & Smith, J. (2004). Evaluation of crumb rubber in hot mix

asphalt.

British Standards Institution (2000). Tests for mechanical and physical properties of

aggregates, Determination of particle density and water absorption, BS EN

1097-6. BSI, London.

British Standards Institution (2012). Bituminous mixtures: Test methods for hot mix

asphalt- Part 34: Marshall test. BS EN 12697-34. BSI, London.

British Standards Institution (2005). Bituminous mixtures: Test methods for hot mix

asphalt- Part 25: Cyclic compression test. BS EN 12697-25. BSI, London.

British Standards Institution (2012). Bituminous mixtures: Test methods for hot mix

asphalt- Part 26: Stiffness. BS EN 12697-26. BSI, London.

British Standards Institution (2002). Bituminous mixtures: Test methods for hot mix

asphalt- Part 29: Determination of the dimensions of a bituminous specimen.

BS EN 12697-29. BSI, London.

Cao, W. (2007). Study on properties of recycled tire rubber modified asphalt

mixtures using dry process. Construction and building materials, 21(5),

1011-1015.

Chen, M., Wan, L., & Lin, J. (2012). Effect of Phase-Change Materials on Thermal

and Mechanical Properties of Asphalt Mixtures. Journal of Testing and

Evaluation, 40(5), 746-753.

Chesner, W., Collins, R., & MacKay, M. (1997). User Guidelines for Waste and By-

product Materials in Pavement Construction, US Department of

Transportation, Federal Highway Administration, Publication No.

Chesner, W. H., Collins, R. J., & MacKay, M. (1998). User guidelines for waste and

by-product materials in pavement construction.

Fadiel, A., Al Rifaie, F., Abu-Lebdeh, T., & Fini, E. (2014). Use of crumb rubber to

improve thermal efficiency of cement-based materials. American Journal of

Engineering and Applied Sciences, 7(1), 1-11.

Garba, R. (2002). Permanent deformation properties of asphalt concrete mixtures.

Norwegian University of Science and Technology.

Ghaly, A. M. (2003). A Mechanistic analysis of static and repeated loading effects on

rubberized asphalt. International Journal of Pavement Engineering, 4(4),

209-219.

117

Golalipour, A. (2011). Modification of multiple stress creep and recovery test

procedure and usage in specification. University of Wisconsin.

Gu, X., Dong, Q., & Yuan, Q. (2014). Development of an Innovative Uniaxial

Compression Test to Evaluate Permanent Deformation of Asphalt Mixtures.

Journal of Materials in Civil Engineering.

Hamed, F. K. M. (2010). Evaluation of Fatigue Resistance for Modified Asphalt

Concrete Mixtures Based on Dissipated Energy Concept. TU Darmstadt.

Huang, X., Xu, T., Zhao, Y., & Li, Z. (2012). Investigation into High-Temperature

Stability of Asphalt Pavement. Journal of Testing and Evaluation, 40(7), 1-6.

Ibrahim, M. R., Katman, H. Y., Karim, M. R., Koting, S., & Mashaan, N. S. (2013).

A Review on the Effect of Crumb Rubber Addition to the Rheology of

Crumb Rubber Modified Bitumen. Advances in Materials Science and

Engineering, 2013.

Jabatan Kerja Raya (JKR) (2008). Standard Specifications for Road Works,

Section4: flexible Pavement, JKR/SPJ/2008-S4. KualaLumpur, Malaysia.

Kalantar, Z. N., Karim, M. R., & Mahrez, A. (2012). A review of using waste and

virgin polymer in pavement. Construction and building materials, 33, 55-62.

Kalofotias, A., Mavridou, S., & Oikonomou, N. (2011). laboratory results of

rubberized asphalt mixtures made by the dry process.

Li, P., Ding, Z., & Zhang, Z. (2013). Effect of Temperature and Frequency on Visco-

Elastic Dynamic Response of Asphalt Mixture. Journal of Testing &

Evaluation, 41(4), 1-8.

Li, P., Jiang, K., & Li, H. (2012). High-Temperature Stability of Asphalt Mixture

with the Influence of Styrene Butadiene Styrene. Procedia-Social and

Behavioral Sciences, 43, 842-848.

Lo Presti, D. (2013). Recycled tyre rubber modified bitumens for road asphalt

mixtures: a literature review. Construction and building materials, 49, 863-

881.

Lu, Y., & Wright, P. J. (2000). Temperature related visco-elastoplastic properties of

asphalt mixtures. Journal of transportation engineering, 126(1), 58-65.

Mashaan, N. S., Ali, A. H., Karim, M. R., & Abdelaziz, M. (2014). A Review on

Using Crumb Rubber in Reinforcement of Asphalt Pavement. The Scientific

World Journal, 2014.

Mashaan, N. S., & Karim, M. R. (2013). Evaluation of Permanent Deformation of

CRM-Reinforced SMA and Its Correlation with Dynamic Stiffness and

Dynamic Creep. The Scientific World Journal, 2013.

McNally, T. (2011). Polymer modified bitumen: properties and characterisation:

Elsevier.

118

Moghadas , N. F., Azarhoosh, A., & Hamedi, G. H. (2014). Effect of high density

polyethylene on the fatigue and rutting performance of hot mix asphalt–a

laboratory study. Road Materials and Pavement Design(ahead-of-print), 1-

11.

Moghaddam, T. B., Karim, M. R., & Abdelaziz, M. (2011). A review on fatigue and

rutting performance of asphalt mixes. Scientific Research and Essays, 6(4),

670-682.

Rahman, M. (2004). Characterisation of dry process crumb rubber modified asphalt

mixtures. University of Nottingham.

Rodríguez, A. A. M., Gallego, J., Pérez, I., Bonati, A., & Giuliani, F. (2014). High

and low temperature properties of crumb rubber modified binders containing

warm mix asphalt additives. Construction and building materials, 53, 460-

466.

Shu, X., & Huang, B. (2013). Recycling of waste tire rubber in asphalt and Portland

cement concrete: an overview. Construction and building materials.

Sousa, J. B., Craus, J., & Monismith, C. L. (1991). Summary report on permanent

deformation in asphalt concrete.

Sun, L., Zhu, H., & Zhu, Y. (2012). Two-Stage Viscoelastic-Viscoplastic Damage

Constitutive Model of Asphalt Mixtures. Journal of Materials in Civil

Engineering, 25(8), 958-971.

Wang, J. C., & Zeng, X. (2006). Influence of temperature and pressure on the

dynamic properties of rubber-modified asphalt concrete. Journal of Materials

in Civil Engineering, 18(1), 125-131.

Way, G. B., Kaloush, K. E., & Biligiri, K. P. (2011). Asphalt-rubber standard

practice guide.

Wong, C. C., & Wong, W.-g. (2007). Effect of crumb rubber modifiers on high

temperature susceptibility of wearing course mixtures. Construction and

building materials, 21(8), 1741-1745.

Xu, T., & Huang, X. (2012). Investigation into causes of in-place rutting in asphalt

pavement. Construction and building materials, 28(1), 525-530.

Yu, M., Wu, G., Zhou, J., & Easa, S. (2014). Proposed compaction procedure for dry

process crumb rubber modified asphalt mixtures using air void content and

expansion ratio. Journal of Testing and Evaluation, 42(2), 1–11.