1. Effect of crumb rubber modifier on physical properties of bitumen
Nuha S. Mashaan
Department of Civil Engineering University of Malaya.
Kuching, Sarawak 2010

2. OUT LINE INTRODUCTION. LITERATURE REVIEW. OBJECTIVES. METHODOLOGY.
RESULT.
CONCLUSION and DISCUSSION
RECOMMENDED

3. INTRODUCTION
WHAT IS BITUMEN?
Bitumen is a mixture of organic liquids that are highly viscous, black, sticky, entirely soluble in carbon disulfide and composed primarily of highly condensed polycyclic aromatic hydrocarbons.

4. What is Asphalt-Rubber?
Asphalt-Rubber as defined by ASTM D 8 :
“Asphalt-Rubber is a blend of asphalt cement,
reclaimed tire rubber and certain additives, in
which the rubber component is at least 15% by
weight of the total blend and has reacted in the
hot asphalt cement sufficiently to cause
swelling of the rubber particles.”

5. INTRODUCTION
The application of ( waste tyres rubber) crumb rubber modifier in asphalt mixture is intended to improve the properties of asphalt binder by reducing the binder’s inherent temperature susceptibility.

6. Interaction between bitumen and CRM binder
Yet, the performance properties of CRM binders in hot mix asphalt pavement be unclear due to various interaction factors of CRM with asphalt binders;
it was concluded that swelling of the rubber particles due to the absorption of the light fractions into rubber particles, and stiffening of the residual binder phase are the main mechanism of the interaction

7. LITERATURE REVIEW
The advantages of using modified bitumen are as follows
Lower susceptibility to daily and seasonal temperature variations
Higher resistance to deformation at high pavement temperature
Better age resistance properties
Higher fatigue life for mixes
Better adhesion between aggregates and binder
and Prevention of cracking and reflective cracking

8. Rubber : is produced from grinding up whole scrap tires and other waste rubber products. Crumb rubber comes in a variety of grades and designations presented by particular size and/or source.

9. OBJECTIVES
The main objective of this study is to evaluate the performance properties of Crumb rubber in fresh bitumen.
To investigate the effect of time and temperature of blending on asphalt binder physical properties.
To improve pavement resistance to rutting .

10. Materials and Tests

11. RESULTS

14. CONCLUSION and DISCUSSION
The following conclusions may be derived from this study:
In general, longer blending time and high blending temperature lead to increase binder performance properties.
The higher softening point and viscosity of rubberized bitumen indicates that the binder is less susceptible to temperature changes hence would increase resistance to flow, resistance to bleeding and resistance to rutting due to higher temperature.
The penetration value decreases as the rubber content added into the bitumen increase. Lower penetration indicates that the modified bitumen become viscous and stiff.

15. THANK YOU