Influence of Tire Crumb Rubber on Properties of Asphalt Binders

Abstract

For many years, the asphalt binder has been used as the elemental material for pavement engineering. The increase in axle loads, heavy traffic, severe climate conditions and construction failures has led many researchers to seek some methods to enhance the bitumen properties. There is a wide range of applications of modifiers for bitumen in road construction. Although various kinds of modifiers have been used widely in reinforcing asphalt concrete, crumb rubber has attracted the most attention due to its high and desirable characteristics. It is realized that the well-distributed modifier can create a strong network in the internal structure of the composite, resulting in asphalt mastic that is more coherent. In the present paper, a laboratory investigation of the physical and rheological properties of various grades of asphalt binder (60-70 penetration grade, 80-100 penetration grade and PG-76 grade) modified with tire crumb rubber. The results showed improvement in physical properties of the modified asphalt binders in terms of decreasing in penetration, increasing in softening point and viscosity values. The modified bitumens exhibited enhanced rheological performance and could raise the grade of bitumen relying on the base asphalt type.