iii

STUDY ON AGEING PROCESS OF POLYMER MODIFIED

BITUMEN

NURUL ‘IZZATI BT AB RAHIM

Thesis submitted in fulfillment of the requirements

for the award of the degree of

Bachelor of Chemical Engineering in Chemical Engineering

Faculty Of Chemical & Natural Resources Engineering

UNIVERSITI MALAYSIA PAHANG

JUNE 2012

viii

ABSTRACT

Bitumen is a very complex combination of organic compound and contain

high proportion of hydrocarbons with high carbon numbers. The main application of

bitumen is in road industry because of its good adhesion to mineral aggregates and its

physical properties. The major failure modes using only bitumen in the road

construction are rutting, cracking and ageing. In cold climates, cracking in pavements

may be an extensive problem. Low temperature cracking is caused by thermally

induced tensile stresses exceeding the tensile strength of the pavement material. By

modified the bitumen using polymer which is Ethylene Vinyl Acetate (EVA) is an

alternative to increase the physical and chemical properties of 80/100 bitumen due to

short term ageing effect. The sample of polymer modified bitumen is prepared using

Toluene as a solvent to bind the polymer with bitumen. The sample then undergoes the

short term ageing process using Thin Film Oven (TFO) before being characterized

using FTIR, Softening Point test, penetrometer, viscometer and TGA. Experimental

results showed that increasing EVA content in the bitumen will reduce the quality of

the bitumen grade, but will improve the performance of bitumen on the environment.

Therefore, the best EVA content to be brought together with bitumen is 2-4%.

ix

ABSTRAK

Bitumen adalah kombinasi yang sangat kompleks terdiri daripada bahan

organik dan mengandungi sebahagian besar hidrokarbon dengan bilangan karbon yang

tinggi. Penggunaan utama bitumen adalah dalam industri penghasilan jalan raya kerana

mempunyai fungsi lekatan yang baik terhadap agregat mineral. Punca kegagalan utama

yang menggunakan bitumen sebagai bahan utama dalam pembinaan jalan raya adalah

keretakan dan penuaan. Keretakan ketika suhu iklim rendah disebabkan oleh tegangan

terma didorong oleh penekanan melebihi kekuatan tegangan bahan turapan. Pengolahan

bitumen menggunakan polimer iaitu Ethylene Vinyl Acetate (EVA) ialah satu alternatif

untuk meningkatkan sifat fizikal dan kimia bitumen grade 80/100 akibat kesan penuaan

jangka pendek. Sampel bitumen yang diolah bersama polimer disediakan menggunakan

Toluene sebagai pelarut untuk menyatukan polimer dan bitumen. Sampel kemudiannya

menjalani proses jangka pendek penuaan menggunakan Thin Film Oven (TFO)

sebelum dianalisis dengan menggunakan FTIR, Analisis Softening point, penetrometer,

Viskometer dan TGA. Hasil uji kaji menujukkan bahawa semakin banyak kandungan

EVA di dalam bitumen akan mengurangkan kualiti grade bitumen tersebut tetapi akan

meningkatkan ketahanan bitumen terhadap persekitaran. Oleh yang demikian,

kandungan EVA yang terbaik untuk disatukan bersama dengan bitumen adalah 2-4%.

x

TABLE OF CONTENTS

Page

SUPERVISOR’S DECLARATION ii

STUDENT’S DECLARATION iii

ACKNOWLEDGMENTS iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES xiv

LIST OF FIGURES xv

LIST OF SYMBOLS xvi

LIST OF ABBREVIATIONS xvii

CHAPTER 1 INTRODUCTION

1.1 Background of Study 1

1.2 Problem statement 2

1.3 Objective of study 3

1.4 Scope of study 3

1.5 Significant of study 4

xi

CHAPTER2 LITERATURE REVIEW

2.1 Bitumen 5

2.1.1 Overview Of Bitumen 5

2.1.2 Application Of Bitumen 6

2.1.3 Properties Of Bitumen 7

2.1.4 Types And Structures Of Bitumen 8

2.2 Polymer 9

2.2.1 Type Of Polymer 9

2.3 Polymer Modified Bitumen 10

2.3.1 Overview Of Polymer Modified Bitumen 10

2.3.2 Interaction Between Polymer And Bitumen 11

2.3.3 Properties Of Polymer Modified Bitumen Using

Ethylene Vinyl Acetate (EVA) 13

2.4 Ageing For Polymer Modified Bitumen 14

2.4.1 Overview Of Ageing Mechanisms 14

2.4.2 Method Of Ageing Process 14

2.4.3 Effect Of Functional Group 15

2.5 Characterization of PMB 16

2.5.1 Fourier Transform Infrared Spectroscopy (FT-IR) 16

2.5.2 Thermagravimetric Analysis (TGA) 16

CHAPTER3 METHODOLOGY

3.1 Introduction 17

3.2 Material 17

3.2.1 Bitumen 17

3.2.2 Ethylene Vinyl Acetate 18

3.2.3 Toluene 19

3.3 Equipment 19

3.3.1 Fourier Transform Infrared Spectroscopy 19

xii

3.3.2 Thin Film Oven 20

3.3.3 Penetrometer 21

3.2.4 Thermogravimetric Analysis(TGA) 22

3.4 Method Of Research 23

3.4.1 Preparation Of Polymer Modified Bitumen 23

3.4.2 Standard Ageing Procedure 25

3.4.3 Analysis Sample 26

3.4.3.1 FTIR Analysis 26

3.4.3.2 Softening Point 26

3.4.3.3 TGA 27

3.5 Research Design 28

CHAPTER4 RESULT AND DISCUSSION

4.1 Introduction 29

4.2 Characterize of PMP on Physical Properties 29

4.2.1 Penetrometer Test 29

4.2.2 Softening Point 31

4.2.3 Penetration Index 33

4.3 Characterize Of PMB On Chemical Properties 34

4.3.1 Fourier Transform Infrared Spectrometry

(FTIR) Analysis 34

4.3.2 TGA Analysis 41

CHAPTER5 CONCLUSION AND RECOMMENDATION

5.1 Conclusion 44

5.2 Recommendation 45

LIST OF REFERENCES 46

APPENDIX 48

xiv

LIST OF TABLES

Table No. Title Page

2.1 Properties PMB using EVA as a polymer 13

3.1 Properties Bitumen 80/100 17

3.2 Properties of EVA 18

3.3 Properties of Toluene 19

4.1 Result on Penetration Test 30

4.2 The value of softening point for each percent EVA in bitumen 31

4.3 The PI before and after ageing process for PMB sample 33

4.4 Wave number (cm–1

) of dominant peak obtained from absorption

spectra and the intensity before ageing 36

4.5 Wave number (cm–1

) of dominant peak obtained from absorption

spectra and the intensity after ageing 39

4.6 TGA result for PMB sample with different EVA content 43

xv

LIST OF FIGURES

Figure No. Title Page

2.1 Global Bitumen Use 6

2.2 Example of broad chemical types present in bitumen 8

2.3 The Microstructure Of Polymer Modified Bitumen 12

2.4 Effect of ageing in bitumen FTIT spectrogram 15

3.1 Thin Film Oven 20

3.2 Penetrometer 21

3.3 Thermogravimetric analysis 22

3.4 Procedure on preparing polymer modified bitumen 24

3.5 Procedure on standard ageing of Polymer Modified Bitumen 25

3.6 Flow diagram of research design 28

4.1 Graft on Penetration Value Versus Percentage of EVA in Bitumen 30

4.2 Graph on Temperature of Softening Point Versus Percentage of EVA

Content 32

4.3 FT-IR wavelength before ageing 35

4.4 FT-IR wavelength after ageing 38

4.5 TGA analysis result 42

xvi

LIST OF SYMBOLS

% Percentage

°C Degree Celsius

xvii

LIST OF ABBREVIATIONS

cm centimeter

cm-1

per centimeter

EVA Ethylene Vinyl Acetate

FT-IR Fourier Transform Infrared Spectrometry

IDT Initial Decomposition Temperature

h hour

L litre

MDT Maximum Decomposition Temperature

mg miligram

ml mililiter

mm milimeter

PI Penetration Index

PMB Polymer Modified Bitumen

rpm revolution per minutes

TFO Thin Film Oven

TGA Thermogravimetric

i

ABSTRACT

Bitumen is a very complex combination of organic compound and contain high

proportion of hydrocarbons with high carbon numbers. The main application of bitumen is in

road industry because of its good adhesion to mineral aggregates and its physical properties. The

major failure modes using only bitumen in the road construction are rutting, cracking and ageing.

In cold climates, cracking in pavements may be an extensive problem. Low temperature cracking

is caused by thermally induced tensile stresses exceeding the tensile strength of the pavement

material. By modified the bitumen using polymer which is Ethylene Vinyl Acetate (EVA) is an

alternative to increase the physical and chemical properties of 80/100 bitumen due to short term

ageing effect. The sample of polymer modified bitumen is prepared using Toluene as a solvent to

bind the polymer with bitumen. The sample then undergoes the short term ageing process using

Thin Film Oven (TFO) before being characterized using FTIR, microstructure analysis,

penetrometer, viscometer and TGA. The increasing of EVA content in bitumen will increase the

viscosity of sample and will reduced the value of penetration.

1

CHAPTER 1

INTRODUCTION

1.1 BACKGROUND OF STUDY

Bitumen are commonly uses especially in road industry because of their good

adhesion to mineral aggregates and their physical properties (Luo & Chen, 2010).

However, during the last decade increase in axle loads, heavy traffic, severe climatic

conditions and construction failures led to a need to enhance the properties of the base

bitumens. Consequently, the properties of bitumen need to be improved with regard to

performance-related properties such as resistance to permanent deformation, low

temperature cracking, wear, stripping and ageing (Mouillet et al., 2008).

Bitumen is one of the fossil organic material that produce from the bottom of the

vacuum distillation columns in the crude oil refineries (Kebritchi et al., 2010). It’s that will

evolves with time , due to ageing process. It also thermoplastic material and have

important limitations due to their temperature sensitivity (Lamontagne et al., 2001) . Using

bitumen in the construction of asphalt pavements for more than a century will affect many

aspects of road performance (Mouillet et al., 2008).

The specific performance enhancers have been investigated such as polymers in

order to obtain the improved bitumen characteristic and properties. Plenty of polymer can

be used in the preparation of polymer-modifies emulsion such as Ethylene Vinyl Acetate

(EVA), Styrene Butadiene Rubber (SBR) latex, Styrene Butadiene Styrene (SBS),

Polychloroprene latex and natural rubber latex. Using the polymer modified bitumen

2

emulsion present a safer and more environmental friendly binder for enhancing the

properties of roads ( Forbes et al, 2001).

1.2 PROBLEM STATEMENT

The major failure modes using only bitumen in the road construction are rutting,

cracking and ageing. In cold climates, cracking in pavements may be an extensive

problem. Low temperature cracking is caused by thermally induced tensile stresses

exceeding the tensile strength of the pavement material. The degree of cracking may be

influenced by many types of factors, such as material, structure and environmental factors.

For example, mixture of a bitumen need to be flexible at high and low temperature. This to

prevent pavement cracking and rutting (Mouillet et al., 2008).

Bitumen ageing is one of the principle factor causing the deterioration of road

pavements (e.g. Cracking, rutting and the road moisture will damage). Ageing is a very

complex process in conventional bitumens and the complexity increases when polymer

modified bitumens are involved. This ageing is cause by the oxidation process where the

oxygen from the surrounding air .Moreover ageing also causes by the temperature and the

changing of the weather (Lu & Isacsson, 2000).

Using the polymer modified bitumen is an alternative method in order to increase

the bitumen performance. Moreover it can improve in performance durability, mitigation

of pavement distress, and reduced life cycle costs compared to unmodified asphalt

emulsions or hot mix asphalt surface dressings (Lu & Isacsson, 2001).

3

1.3 OBJECTIVES OF STUDY

Based on the research background and problem statement described in the previous

section, the objective of this research to study the ageing process and properties of polymer

modified bitumen

1.4 SCOPE OF RESEARCH

In order to handle the above mentioned objectives, the following scopes were drawn:

a) Preparing the polymer modified bitumen using the toluene as a solvent.

b) Preparing the ageing process of polymer modified bitumen using Thin film Oven

c) The prepared polymer modified bitumen will be characterized by using FTIR ,

Softening Test, Penetrometer and TGA.

4

1.5 BENEFITS AND SIGNIFICANT OF RESEARCH

The rationale and significance of this research is to create a safer and more

environmentally friendly binder for enhancing the properties of road. Besides that the

polymer modified bitumen will offer improvement of the road performance. Using

polymer modified bitumen will help reduce maintenance and the life cycle costs of the

road.

5

5

CHAPTER 2

LITERATURE REVIEW

2.1 BITUMEN

2.1.1 Overview of bitumen

Bitumen is a very complex combination of organic compound and its contain high

proportion of hydrocarbons with high carbon numbers.Bitumen is the residual product

from distillation of crude oil in petroleum refining and produced to meet a variety of

specifications based upon physical properties. The common refining process used for

producing bitumen is straight reduction to grade from petroleum crude oil or blend.

This process is usually using atmospheric and vacuum distillation as major

equipment. Bitumen can be further processed by blowing air through it at elevated

temperatures to alter its physical properties for commercial application (Asphalt

Institute, 2011).

6

2.1.2 Application of Bitumen

According to Asphalt Institute Inc., the current world consumption of bitumen

is approximately 102 Million tonnes per year. Figure 2.1 show the percentage global

bitumen use. At least 34% from 102MT per year bitumen are use in North America,

followed by 30% had been used in Asia and pacific and at least 20% bitumen use in

European Union.

Figure 2.1: Global Bitumen use

From 102 MT/yr consumption of bitumen, 85% of all the bitumen is used as

the binder in various kind of asphalt pavements: pavements for roads, airports,

parking lots, etc. The other 10% of bitumen is used for roofing and the rest of the

bitumen , about 5% of the total is used for a variety of purposes, each very small in

volume. This sector is referred as ‘Secondary Uses’ (Asphalt Institute, 2011).

7

2.1.3 Properties of Bitumen

Bitumen is an organic liquid mixture that is highly viscous, black, sticky,

entirely soluble in carbon disulfide, and composed primarily of highly condensed

polycyclic aromatic hydrocarbons. Bitumen also known as asphalt or tar (Hirst, 2003).

Bitumen are the residual product obtain by fractional distillation of crude oil at the

bottom fraction. Bitumen one of the most complex molecules found in nature and the

one with the highest boiling point.

At ambient temperature in-situ, bitumen is solid and virtually non-volatile and

the vapor pressure of in-situ bitumen is below the limit of detection for normal

instrumentation. Normally bitumen is heated to >140 oC to become liquid to facilitate

transportation and handling (Asphalt Institute, 2011).

8

2.1.4 Types and structures of bitumen functional group

Generally the chemical composition of bitumen is similar, but with some

variation depending upon the original crude oil and on the process used during

refining and blending. Bitumen can be described as complex mixtures containing a

large number of different chemical compounds of relatively high molecular weight.

The molecules contain in bitumen are combinations of alkanes, cycloalkanes,

aromatics and hetromolecules (which is contain sulphur, oxygen, nitrogen and heavy

metals). The significance of molecules containing hetero-atoms in bitumen chemistry

is the ability to form molecular associations, which strongly influence the physical

properties and performance of bitumen.

Functionality of bitumen related on how molecules interact with each other or/and

with aggregate surfaces or/and other materials. Typically, bitumen contains

predominantly cyclic hydrocarbons (aromatic and/or naphthenic) and less quality of

saturated components which are mainly very low in chemical reactivity. Figure 2.2

below show the example of broad chemical types present in bitumen (Asphalt

Institute, 2011).

Figure 2.2: Example of broad chemical types present in bitumen

9

2.2 POLYMER

Polymer is molecules which consist of a long, repeating chain of smaller units that

called monomer. Polymer consist billions of atoms and have the highest molecular weight

among any molecules (Anissimov, 2011).

2.2.1 Type of Polymer

The common polymer that usually use in the bitumen modification are :

i. Plastomers

ii. Elastomers

EVA (Ethylene-Vinyl-Acetate) and PE (Polyethylene) are example of plastromers

and SBS (Styrene-Butadiene-Styrene) is the most used elastomer. Basically, plastomers

will increase the viscosity and stiffness of the bitumen while elastomers will improve the

elastic behavior of the bitumen (Rooijen et al, 2006). These type of polymers usually

provide in the form of pellets or powder which can easily diluted to the required polymer

content by blending with base bitumen by using low to high shear mixers (Sengoz et al,

2009).

10

2.3 POLYMER MODIFIED BITUMEN

2.3.1 Overview of Polymer Modified Bitumen

Polymer modified Bitumen (PMB) is relate to the process for preparation of

polymer and rubber based modified binder which is useful for the construction of roads

catering to heavy traffic and also for the formation of airfields and surfacing. It also

used as interlayer for sealing of cracks, preventive maintenance of flexible and can

delay the reflective cracking (Juno Bitumix Private Limited, 17 Oktober 2011).

Bitumen modified with polymer is a common means of providing resistance

to pavement deformation. Polymer modified bitumen emulsion is on alternative to

improve the pure bitumen performance (Mouillet et al., 2008). It also can improve

resistance in cracking which result in stronger and more durable overlays even in

extreme climatic conditions. Both elastomer and plastomer modified bitumen have

been apply successfully in situations where rutting was a problem with penetration

grade bitumen (up to alimit). However, the bitumen should not be too stiff, because that

may result in brittle asphalt mixtures, which has caused severe cracking failures with

some types of plastomer modified bitumen in practice (Rooijen et al, 2006).

When bitumen is added in a compatible elastomer (such as SBS), it will

absorb the oily fraction from bitumen which causes the polymer swell. After a while,

the swelled polymer starts to dissolve in the bitumen. This physical process takes at

least several hour and can be influenced by the production process and the use of

additives. Meanwhile Plastomersmelt at high temperature and when added to bitumen it

will appear as small droplets that are dispersed in the bitumen. The bigger the volume

of the polymer in the bitumen, the more it will affect the properties of the bitumen

(Rooijen et al, 2006).

11

2.3.2 Interaction between polymer and bitumen

The result of the mutual effect of polymer and bitumen are the morphology of

polymer modified bitumen, influenced by bitumen composition, polymer nature and

ratio. Commonly, polymer is insoluble to some degree in the bitumen matrix by

resulting eventually in gross separation of both phase. These phase may become either

continuous phase or dispersed, depending on polymer nature, concentration and ability

to swell with maltene molecules (Eweed, 2011).

In general at lower polymer content the small polymer spheres swollen by

bitumen compatible fractions are spread homogeneously in a continuousbitumen phase.

By increasing polymer contain will resulting a continuous polymer phase. Figure 2.3

below show the microstructure of polymer modified bitumen which contains high

polymer content and low polymer content (Rooijen et al, 2006).