UNIVERSITI PUTRA MALAYSIA

EVALUATION OF A LABORATORY ASPHALT ROTARY

COMPACTOR

HAMED HAGHIGHI

FK 2009 51

i

EVALUATION OF A LABORATORY ASPHALT ROTARY COMPACTOR

BY

HAMED HAGHIGHI

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia,

in Fulfilment of the Requirement for the Degree of Master of Science

April 2009

ii

DEDICATION

This thesis is especially dedicated to:

My lovely Wife:

Masoomeh Tehranirokh

My Praiseworthy Parents:

Mohammad Ali Haghighi

&

Batool Ghofranpanah

My Reverent In-laws:

Hossein Tehranirokh

&

Fatemeh Ghasemi

iii

Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfillment of the requirement for the degree of Master of Science

EVALUATION OF A LABORATORY ASPHALT ROTARY COMPACTOR

By

HAMED HAGHIGHI

April 2009

Chairman: Associate Professor Ratnasamy Muniandy , PhD

Faculty: Engineering

Several studies have shown that Marshall Compactor, California Kneading

Compactor and Gyratory Compactor, the most conventional compactors, are not able

to produce laboratory specimens that can truly represent the mixtures compacted in

the field. However gyratory compactor fairly gives good simulation of the field roller

compactor but no universally approved laboratory compactor has been developed to

compact slabs for the wheel tracking and fatigue test. Compacting and preparing

more than one sample at the same time is another matter of concern which these

conventional compactors cannot achieve. Hence, a suitable laboratory compaction

procedure is inevitable. Rotary compactor, a laboratory roller compactor was

developed by researches from Universiti Putra Malaysia (UPM). This study was

conducted to evaluate the performance of rotary compactor as a laboratory asphalt

compactor and incorporated three objectives: to establish a laboratory protocol

including procedures and standards for using the UPM rotary compactor, to evaluate

the consistency of SMA slabs in terms of thickness and frictional resistance

properties, and to validate the use of UPM rotary compactor in achieving the SMA

iv

mixtures’ requirements for bulk specific gravity, voids, Marshall stability and flow,

resilient modulus and resistance to degradation. To compact a rotary slab to the

desired thickness of 65 mm and 4% air voids, the applied pressure was recommended

to start from 0 bar (as pre compaction) and stop at 1.5 bar with intervals of 0.25 bar.

For each value of applied pressure, 6 number of passes (rotations) were needed (3

passes per each direction). The speed of rotation was recommended to be fixed on 10

Hz (3.29 RPM). Based on checking 315 points of three slabs to measure the

thickness and the statistical analysis of these three slabs, the overall thickness of the

slabs was almost uniform along the slabs. According to analyzing the performance of

132 core specimens it was concluded that rotary compactor was able to produce slabs

with uniformly distributed properties such as volumetric properties, Marshall

stability, flow and resilient modulus. Finally a degradation study was carried out to

check and evaluate whether the aggregate structure was changed during the mixing

and compacting. It was found that two aggregate fractions (12.7 mm and 9.5 mm)

were affected and crushed during mixing and compacting procedures. To compensate

the observed loss percentages a value called weight factor was introduced to provide

the loss of materials.

v

Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia Sebagai memenuhi keperluan untuk ljazah Master Sains

PENILAIAN MESIN PENGGELEK PEMADATAN PEMADAT ASFALT DI

MAKMAL

Oleh

HAMED HAGHIGHI

April 2009

Penyelia: Prof. Madya Ratnasamy Muniandy , PhD

Fakulti: Kejuruteraan

Hasil beberapa kajian telah menunjukkan bahawa mesin pemadat Marshall, pemadat

uli California dan pemadat berputar, adalah jenis mesin pemadat global yang paling

konvensional, ia tidak mampu menghasilkan spesimen makmal yang yang benar-

benar mewakili campuran yang telah dipadatkan seperti di tapak. Walaupun pemadat

berputar dapat menghasilkan simulasi yang baik seperti mesin penggelek di tapak

untuk tujuan pemadatan, tetapi ia tidak secara umumnya untuk diperkembangkan

sebagai pemadat kepingan untuk wheel tracking dan ujian kelesuan. Pemadatan dan

penyediaan lebih dari satu sampel pada satu masa yang sama adalah satu perkara

yang perlu diberi perhatian yang mana ia tidak dapat diperolehi melalui pemadat

konvensional. Oleh itu, satu prosedur pemadatan di makmal yang sesuai perlu

diwujudkan. Mesin pemadat rotary, sejenis mesin penggelek telah dihasilkan dan

diperkenalkan oleh penyelidik dari Universiti Putra Malaysia (UPM). Penyelidika n

dan kajian ini dijalankan untuk menilai prestasi mesin penggelek ini sebagai pemadat

asfalt dan telah menggabungkan tiga objektif utama; untuk menghasilkan protokol di

makmal termasuk prosedur dan piawai dalam menggunakan alat ini, untuk menilai

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konsistensi kepingan SMA dari segi ketebalan dan ciri- ciri rintangan geseran, dan

untuk mengesahkan penggunaan mesin penggelek UPM dalam mencapai keperluan

campuran SMA untuk spesifik graviti pukal, kandungan udara, kestabilan Marshall

dan aliran, ketahanan modulus dan rintangan degradasi. Untuk memadatkan

kepingan kepada ketebalan yang dikehendaki iaitu 65 mm dan 4% kandungan udara,

tekanan yang disyorkan untuk dikenakan permulaannya dari 0 bar (sebagai

pemadatan awal) dan berhenti pada 1.5 bar dengan se lang rehat 0.25 bar. Untuk

setiap nilai tekanan yang dikenakan enam nombor putaran diperlukan (3 untuk setiap

arah putaran). Kelajuan putaran yang disyorkan adalah 10 Hz (3.29 RPM).

Berdasarkan pemeriksaan ke atas 315 titik untuk tiga kepingan dalam menguk ur

ketebalan dan analisis statistik, kesemua tebal kepingan adalah hampir sama untuk

setiap kepingan. Merujuk kepada analisis prestasi 132 spesimen, dapat disimpulkan

yang mesin penggelek ini mampu menghasilkan kepingan yang hampir sama rata

agihan sifatnya seperti kestabilan Marshall dan modulus ketahanannya. Akhir sekali,

satu kajian penurunan (degradasi) dijalankan untuk mengkaji dan menilai sama ada

struktur agregat telah berubah ketika proses campuran dan pemadatan. Telah

dibuktikan yang dua pecahan agregat (12.7 mm dan 9.5 mm) telah dikesan dan telah

pecah melalui proses campuran dan pemadatan. Untuk menggantikan peratus

kekurangan yang telah dikesan, satu nilai yang dipanggil faktor berat telah

diperkenalkan untuk memperlengkap kekurangan di dalam bahan yang digunakan.

vii

ACKNOWLEDGEMENTS

In the Name of Allah, Most Gracious, Most Merciful, all praise and thanks are due to

Allah, and peace and blessings be upon His Messenger. I would like to express the

most sincere appreciation to those who made this work possible; supervisory

members, Friends and Family.

Firstly I would like to thank my supervisor Prof. Madya Dr. Ratnasamy Muniandy

for the many useful advice and discussions, for his constant encouragement,

guidance, support and patience all the way through my study work. Equally the

appreciation extends to the supervisory committee members Prof. Madya. Ir.

Salihuddin Hassim and Prof. Madya Dr. Robiah Bt. Yunus for providing me the

opportunity to complete my studies under their valuable guidance.

I would also like to acknowledge the Civil Engineering Department of Universiti

Putra Malaysia for providing the numerous facilities and support for this research

work.

Thanks and acknowledgements are meaningless if not extended to my wife who

always gave relentless encouragement and support which made my education

possible.

Last but not least, my very special thanks to all my friends who were directly and

indirectly involved in this research and cooperated with this study.

viii

I certify that a Thesis Examination Committee has met on 13 April 2009 to conduct the final examination of Hamed Haghighi on his thesis entitiled "Evaluation of a Laboratory Asphalt Rotary Compactor" in accordance with the Univesrities and

University Colleges Act 1971 and the Constitution of the Universiti Putra Malaysia [P.U. (A) 106] 15 March 1998. The committee recommends that the student be

awarded the Master of Science. Members of the Examination Committee are as follows:

Husaini b. Omar, PhD

Associate Professor Faculty of Engineering

Universiti Putra Malaysia (Chairman)

Hussain b. Hamid, PhD

Senior Lecturer Faculty of Engineering

Universiti Putra Malaysia (Internal Examiner)

Wan Ishak b. Wan Ismail, PhD

Professor

Faculty of Engineering Universiti Putra Malaysia

(Internal Examiner)

Meor Othman Hamzah, PhD

Professor

Faculty of Engineering Universiti Sains Malaysia (External Examiner)

___________________________________ BUJANG KIM HUAT, PhD

Professor and Deputy Dean

School of Graduate Studies Universiti Putra Malaysia

Date: 18 June 2009

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This thesis submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfillment on the requirement for the degree of Master of Science. The members of the supervisory committee are as follows:

Ratnasamy Muniandy, PhD

Associate Professor

Faculty of Engineering Universiti Putra Malaysia (Chairman)

Robiah bt. Yunus, PhD

Associate Professor Faculty of Engineering

Universiti Putra Malaysia (Member)

Ir Salihudin b. Hassim

Associate Professor Faculty of Engineering Universiti Putra Malaysia

(Member)

__________________________________ HASANAH MOHD. GHAZALI, PhD

Professor and Dean School of Graduate Studies Universiti Putra Malaysia

Date: 9 July 2009

x

DECLARATION

I hereby declare that the thesis is based on my original work as per program given to

me, except for quotations and citations, which have been duly acknowledged. I also

declare that it has not been previously or concurrently submitted for any other degree

at UPM or other institutions.

__________________________________ HAMED HAGHIGHI

Date:

xi

TABLE OF CONTENTS

DEDICATION ii

ABSTRACT iii ABSTRAK v

ACKNOWLEDGEMENTS vii APPROVAL Error! Bookmark not defined. DECLARATION x

LIST OF TABLES xiii LIST OF FIGURES xvi

LIST OF ABBREVIATIONS xx

CHAPTER

1 INTRODUCTION 1

1.1 General Background 1 1.2 Problem Statement 4 1.3 Objectives of Study 6

1.4 Scope of Study 6 1.5 Thesis Layout 7

2 LITERATURE REVIEW 8 2.1 Classification of Hot Mixes 8

2.2 Asphalt Mix Design Methods 9 2.2.1 Aggregate Selection and Testing 12 2.2.2 Asphalt Binder Selection and Testing 12

2.2.3 Cellulose Fiber Selection and Testing 13 2.2.4 Optimum Asphalt Content 16

2.3 Asphalt Mixture Compaction 20 2.3.1 Need for Compaction 21 2.3.2 Mechanics of Compaction 21

2.3.3 Factors Affecting Compaction 23 2.4 Major Laboratory Asphalt Mixture Compactors 32

2.4.1 California Kneading Compactor 32 2.4.2 Marshall Impact Compactor 34 2.4.3 Superpave Gyratory Compactor 36

2.5 Other Types of Laboratory Compactors 41 2.5.1 Rolling Wheel Compactor 41

2.5.2 Linear Kneading Compactor 44 2.5.3 French Plate Compactor 46 2.5.4 Vibrocompression Specimen Compactor 47

2.5.5 Asphalt Vibratory Compactor 48 2.5.6 Turamesin 49

2.5.7 UPM Rotary Compactor 52 2.6 Comparative Study of Laboratory Compaction Methods 52 2.7 Field Compaction 56

2.8 Stone Matrix Asphalt (SMA) Mixtures 60 2.8.1 Background 61

2.8.2 Advantages of SMA 63 2.8.3 SMA Mix Design and Specifications 64

xii

2.9 Frictional Properties of Mixture 70 2.10 Summary 72

3 RESEARCH METHODOLOGY 74 3.1 Introduction 74

3.2 Test Plan 1: Criteria Establishment of Rotary Compactor 79 3.2.1 Slab Preparation and Compaction 79 3.2.2 Correlation Study of Rotary Compactor Variables 90

3.3 Test Plan 2: Consistency Analysis of SMA Slabs 90 3.3.1 Physical Properties of the Aggregate 91

3.3.2 Physical Properties of the Asphalt Binder 91 3.3.3 Physical Properties of the Cellulose Fiber 92 3.3.4 Marshall Method of Mix Design 93

3.3.5 Preparation and Thickness Analysis of Slabs 100 3.4 Test Plan 3: Frictional Resistance Study on compacted slabs and

Performance Tests Analysis on Cored Specimens 100 3.4.1 Skid Resistance 101 3.4.2 Macro Texture Depth 102

3.4.3 Resilient Modulus 105 3.4.4 Cantabro Loss 106

3.4.5 Degradation Study 107 3.5 Summary 109

4 RESULT AND DISCUSSION 110 4.1 Test Plan 1: Criteria Establishment of Rotary Compactor 110

4.1.1 Two Dimensions Drawings 110

4.1.2 Three Dimensions Schematic Drawings 113 4.1.3 Inventory and Specifications of Parts 115

4.1.4 Procedure Establishment of Slab Preparation 121 4.2 Test Plan 2: Consistency Analysis of SMA Slabs 137

4.2.1 Material Selection and Testing 137

4.2.2 Asphalt Mix Design 146 4.2.3 Thickness Analysis 155

4.3 Test Plan 3: Frictional Resistance Study on Compacted Slabs and Performance Tests Analysis on Slab Cored Specimens 167 4.3.1 Frictional Resistance Analysis 167

4.3.2 Core Specimens Performance Analysis 173 4.3.3 Degradation Study 186

5 CONCLUSION AND RECOMMENDATIONS 192 5.1 Summary 192

5.2 Conclusions 193 5.3 Recommendation for Further Studies 195

REFERENCES 197 APPENDICES 204

BIODATA OF STUDENT 227

xiii

LIST OF TABLES

Table Page

2.1. Cellulose Content and Spiral Angle of Various 16

2.2. Elastic Properties of Cellulose, Hemicellulose, and Lignin 16

2.3. Summary of Influences on Compaction 31

2.4. Marshall Mix Design Criteria 35

2.5. Superpave Gyratory Compactive Effort 39

2.6. Some of the CRT-RC Roller Compactor Specifications 43

2.7. Summary of Thickness Analysis 51

2.8. Summary of Engineering Properties of Laboratory and Field Compacted Specimens 57

2.9. Contact Pressure at various Penetration Depths 59

2.10. General Properties of 3 Types of HMA 64

2.11. Specifications for German Stone Matrix Asphalt 65

2.12. Specifications for Danish Stone Matrix Asphalt 65

2.13. Coarse Aggregate Quality Requirements 66

2.14. Fine Aggregate Quality Requirements 66

2.15. Example SMA Gradation Specification 67

2.16. SMA Mixture Specification for Marshall Compacted Designs 69

2.17. SMA Mixture Specification for Gyratory Compacted Designs 70

3.1. Aggregate Physical Properties Tests 91

3.2. Asphalt Binder Physical Properties Tests 92

3.3. Minimum Values for Skid Resistance 102

3.4. Texture Depth and Volume Relationship 103

3.5. Indirect Tensile Stiffness Modulus Parameters 106

4.1. Desired Amount of Aggregate Fractions 123

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4.2. Required Amount of Materials per Batch 124

4.3. Hertz – Velocity Relations 127

4.4. Penetration Depth of Rotary Roller 129

4.5. Rotary Compactor Procedure of Compaction 135

4.6. Penetration Test Result 138

4.7. Softening Point Result 138

4.8. Viscosity of Asphalt Binder 138

4.9. Specific Gravity Result 139

4.10. Los Angeles Abrasion Result 140

4.11. Aggregate Impact Value Result 140

4.12. Flakiness Index Result 141

4.13. Elongation Index Result 141

4.14. Coarse Aggregate Angularity Results 142

4.15. Fine Aggregate Angularity Results 142

4.16. Bulk Specific Gravity of Aggregate Fractions 143

4.17. SMA Gradation Specification 143

4.18. Mesh Screen Analysis of Cellulose Fiber 145

4.19. Oil-Fiber Draindown Result 146

4.20. Maximum Specific Gravity Results 147

4.21. Bulk Specific Gravity Results for Marshall Mix Design 148

4.22. Air-Voids Analysis for Marshall Mix Design 149

4.23. Resilient Modulus Results for Marshall Mix Design 150

4.24. Marshall Stability and Flow Results 151

4.25. Summary of Marshall Mix Design Analysis 152

4.26. t Test Result for Slab One 158

xv

4.27. t Test Result for Slab Two 161

4.28. t Test Result for Slab Three 164

4.29. Summary of Skid Resistance Results 168

4.30. Summary of ANOVA for Skid Resistance of Three Slabs 168

4.31. ANOVA Result for Skid Resistance of Three Slabs 168

4.32. Texture Depth Measurements 171

4.33. Summary of ANOVA for Texture Depth (Close to Inner) 171

4.34. ANOVA Result for Texture Depth (Close to Inner) 172

4.35. Summary of ANOVA for Texture Depth (Close to Outer) 172

4.36. ANOVA Result for Texture Depth (Close to Outer) 172

4.37. Summary of Bulk Specific Gravity and Air Voids 173

4.38. Summary of t Test for Air Voids in Ring Analysis 174

4.39. t Test Results of Outer Ring 174

4.40. Summary of ANOVA for Ring Analysis of Air Voids 176

4.41. ANOVA Result for Ring Analysis of Air Voids 176

4.42. Summary of t Test for Air Voids in Quadrant Analysis 177

4.43. Summary of ANOVA for Quadrant Analysis of Air Voids 179

4.44. ANOVA Result for Quadrant Analysis of Air Voids 179

4.45. Resilient Modulus Results – Slab One 180

4.46. Resilient Modulus Results – Slab Two 181

4.47. Resilient Modulus Results – Slab Three 182

4.48. Weight Factor Determination 189

xvi

LIST OF FIGURES

Figure Page

1.1. Road Network Growth Trend 1

1.2. Comparison of Road Use for Passenger and Freight Transport 2

1.3. Percent of Total Annual Hot Mix Asphalt Production in 2006 3

2.1. An Empty Fruit Bunch (left) and Its Fibrous Form (right) 14

2.2. Percent Draindown without Cellulose Fiber 15

2.3. Percent Draindown with Cellulose Fiber 15

2.4. Diagram Illustrating Air Voids and Voids in Mineral Aggregate 18

2.5. Hot Mix Asphalt Component Diagram 18

2.6. Pavement Durability versus Air Voids 22

2.7. Forces at Work during Compaction 23

2.8. Time Allowed for Compaction 30

2.9. California Kneading Compactor 33

2.10. Composite Photo of Marshall Compactor Components 34

2.11. Schematic View of Superpave Gyratory Compactor 37

2.12. Superpave Gyratory Compactor Mold Configuration 38

2.13. Comparative Studies of Relative Stiffness of Laboratory Compactions due to Field Compaction 42

2.14. European Standard Roller Compactor (CRT-RC) 43

2.15. Linear Kneading Compactor 45

2.16. Rollers inside the Compactor 45

2.17. French Plate Compactor 46

2.18. Asphalt Vibratory Compactor 49

2.19. Turamesin 50

xvii

2.20. UPM Rotary Compactor 52

2.21. An Example of a Roller Pattern Using a Test Strip 58

2.22. Contact Angle of a Steel Drum 60

2.23. An Example of SMA Gradation Specification 67

2.24. Mortar in SMA 68

2.25. Skid Number for Different Types of Asphalt Mixes 72

3.1. Test Plan 1: Criteria Establishment of Rotary compactor 75

3.2. Test Plan 2: Consistency Analysis of SMA Slabs 76

3.3. Test Plan 3: Frictional Resistance Study on Compacted Slabs and Performance Tests Analysis on Slab Core Specimens 77

3.4. Comprehensive Experimental Design 78

3.5. Cut Marking of the Slab 86

3.6. Longitudinal and Cross Sectional Lines 86

3.7. Core Marking Plan for Slab Quadrant 87

3.8. Applying Coring Plan on Each Slab Quadrant 87

3.9. Marking the Cutter Blade 88

3.10. Coring 100 mm Specimen from Slab Quadrant 89

3.11. Sequences of Adding the Materials 95

3.12. Water Bath for Marshall Specimens 97

3.13. Marshall Test Apparatus 97

3.14. Loose Form of Specimen (i) and Wire Basket (ii) 99

3.15. British Pendulum on the Compacted Slab 102

3.16. Texture Depth Determination 103

3.17. Sand Patch Set-Up 104

3.18. Core Specimens Before (i) and After (ii) Cantabro 107

3.19. Asphalt Binder Extraction: Before (i), After (ii) 108

xviii

3.20. Quartering with Riffle Box 109

4.1. Mold Assembly Dimensions 111

4.2. Main Frame Assembly Dimensions 112

4.3. Roller Assembly Dimensions 113

4.4. Rotary Compactor 3D Schematic Drawing - 1 114

4.5. Rotary Compactor 3D Schematic Drawing - 2 114

4.6. Rotary Compactor Mold’s Details 115

4.7. Rotary compactor Pressure Gauge 116

4.8. Rotary compactor Control Panel 117

4.9. Rotary compactor Motor 117

4.10. Rotary Compactor’s Frame Wheel 118

4.11. Rotary compactor Rollers 118

4.12. Rotary Compactor’s Hand Valve 119

4.13. Rotary Compactor’s Pneumatic Pressure Cylinder 120

4.14. Rotary Compactor’s Main Trunk 120

4.15. Velocity Conversion Diagram 126

4.16. Rotary Roller Penetration Depth 128

4.17. Pushing the Materials 129

4.18. Crushed Stones Due to the High Pressure Applied 130

4.19. Contact Area of the Rotary Roller 131

4.20. Humps on Finished Slab 132

4.21. Time versus Temperature for Trial Slab One 133

4.22. Time versus Temperature for Trial Slab Two 134

4.23. Time versus Temperature for Trial Slab Three 135

4.24. Pressure – Temperature Correlation 136

xix

4.25. Temperature -Viscosity Relationship 139

4.26. SMA Gradation Specification 144

4.27. Particle Size Distribution of Cellulose Fiber 145

4.28. Percent Draindown vs. Time 146

4.29. Marshall Mix Design Property Curves 153

4.30. Testing the Hypothesis for the Mean of 65 mm 158

4.31. ANOVA Single Factor for Slab One Using Microsoft Excel® 159

4.32. Regions of Rejection and Nonrejection for ANOVA 160

4.33. Thickness Variation through the Slab One 160

4.34. ANOVA Single Factor Analysis for Slab Two 162

4.35. Thickness Variation through the Slab Two 163

4.36. ANOVA Single Factor Analysis for Slab Three 165

4.37. Thickness Variation through the Slab Three 166

4.38. Thickness Comparison of the Slabs 166

4.39. Surface Texture of Slab One 169

4.40. Two Positions for Texture Depth 170

4.41. Mean of Bulk Specific Gravity and Air Voids of Three Slabs 175

4.42. Mean of Bulk Specific Gravity and Air Voids of Three Slabs 178

4.43. Mean Resilient Modulus at 25 ºC 183

4.44. Mean Value of Marshall Stability and Flow 185

4.45. Mean Value of Cantabro Loss at Different Revolutions 186

4.46. Percent Retained on Different Fractions 187

4.47. Percent Passing of Reclaimed Aggregates 188

4.48. Particle Shape of Reclaimed Aggregates 190

4.49. Reclaiming of Cellulose Fiber 191

xx

LIST OF ABBREVIATIONS

AAMAS Asphalt Aggregate Mixture Analysis System

AASHTO American Association of State Highway and Transportation Officials

AMIR Asphalt Multi-Integrated Roller

ANOVA Analysis of Variation

APA Asphalt Pavement Analyzer

ASTM American Society for Testing and Materials

AVC Asphalt Vibratory Compactor

BS British Standard

COV Coefficient of Variation

EFB Empty Fruit Bunch

ESAL Equivalent Single Axle Load

FHWA Federal Highway Administration

GTM Gyratory Testing Machine

HMA Hot Mix Asphalt

ITSM Indirect Tensile Modulus Test

JIRCAS Japan International Research Center for Agricultural Sciences

JKR Jabatan Kerja Raya

LCPC Laboratoire Central des Ponts et Chaussees

LVDT Linear Variable Differential Transducer

LWT Loaded Wheel Tracking

MATTA Material Testing Apparatus

NAPA National Asphalt Pavement Association

NCAT National Center for Asphalt Technology

xxi

NCHRP National Cooperative Highway Research Program

OGFC Open Graded Friction Course

PLUS Projek Lebuhraya Utara-Selatan

PTI Pavement Technology Incorporation

RPM Revolutions Per Minute

SGC Superpave Gyratory Compactor

SHRP Strategic Highway Research Program

SMA Stone Matrix Asphalt

SSD Saturated Surface Dry

Superpave Superior Performing Asphalt Pavement

SWPE Scott Wilson Pavement Engineering

TMD Theoretical Maximum Density

UPM Universiti Putra Malaysia

VCA Voids in Coarse Aggregate

VFA Voids filled with Asphalt

VMA Voids in Mineral Aggregates

VTM Voids in Total Mix

1

CHAPTER 1

1 INTRODUCTION

1.1 General Background

The Malaysian road network has been expanding steadily, from 54,000 km in 1990

to about 80,000 km in 2007, including 78,300 km of State or Federal roads and 1,700

km of toll highways. The total number of registered vehicles has been exceeded 13

million and the average annual growth of vehicle ownership is over 7.0% per year

whereas the increase in road length is less than 4.0% per annum as displayed in

Figure 1.1 (Vellu, 2007).

Figure ‎1.1. Road Network Growth Trend

(Source: Vellu, 2007)

Road transport continues to be the most popular way of transportation for both

passenger and freight. Figure 1.2 shows 94.8% of passengers and 96.4% of freight

movement are transported by road. This importance on road transport makes it

difficult to the efficiency of the whole transport system. (Vellu, 2007)

0

20

40

60

80

100

1990 1995 2000 2005

Year

Kilom

eter

s (T

hou

san

ds) State

Federal

2

Figure ‎1.2. Comparison of Road Use for Passenger and Freight Transport

(Source: Vellu, 2007)

Due to this high percentage of using the roads and the steady increase of vehicles

there is a growing concern for comfort driving, safety, maintenance and

environmental considerations, which has led to more durable, reliable, stronger and

greener pavements, focusing particularly on asphalt mixtures.

Another considerable issue is the recent surge in global petroleum prices that has led

to US$120 per each barrel of crude oil in June 2008 (Hendrickson, 2008). World

consumption of crude oil has now reached 1000 barrels per second (Tertzakian,

2006). Thus most of the past practice and research in transportation engineering

which had assumed reliance on petroleum for transportation fuel with fairly stable or

declining petroleum prices cannot be no longer true.

Since the unit cost for constructing and maintaining roads has increased over the

years, the road sector has to compete with other economic sectors for adequate funds.

Efficient techniques in designing and constructing roads are therefore in demand and

based on that, roads perform better and last longer. Stone Matrix Asphalt (SMA) is

one type of asphalt mixtures which is a tough, stable and rut resistance mixture and

relies on stone-to-stone contact to provide strength and a rich mortar binder to

Freight Transport

Air, 0Rail, 1 Maritime, 2

Road, 97

Passenger Transport

Road, 94

Rail, 5 Air, 1

3

provide durability. SMA generally contains about 70% of coarse aggregate and about

6-8% asphalt cement (Kast, 1985). For SMA Mix design several factors must be met.

Among them are: to provide stone-on-stone contact through the selection of the

proper gradation, to design an asphalt content at least 6 percent and air void content

of 4 percent, to meet moisture susceptibility and draindown requirements and to

design for voids in the mineral aggregate such that at least 17 percent is obtained

(NAPA, 1999).

Development of SMA began in the 1960s in Germany and introduced in US in 1991.

First full scaled field trial was carried out in Malaysia in 2005 (Shahid, 2008). Figure

1.3 shows the percentage of the SMA production from the total HMA production in

some European countries in 2006 and also conveys the increase of SMA application.

Based on the unique advantages of SMA and fast developing of it around the world,

changing over to SMA seems inevitable.

Figure ‎1.3. Percent of Total Annual Hot Mix Asphalt Production in 2006

(Source: European Asphalt Pavement Association, 2006)

0

10

20

30

40

50

Austria Belgium Germany Poland Sweden Hungary

Percen

t

Country