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

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

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.

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.”

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.

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

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

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.

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 .

Materials and Tests

RESULTS

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.

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