Rheological Properties of Rubber-Modified Asphalt

The performance of rubber (from used tires) as an asphalt cement modifier was evaluated by performing experiments on the shear-flow properties and creep-rupture behavior of modified asphalt cements. Results indicate that various asphalt/rubber samples exhibit shear-thickening, Newtonian, and shear-thinning behavior depending on the shear rate. The shear viscosity, linear viscoelastic functions, elasticity, and creep resistance of asphalt cement increased with the addition of rubber. These increases indicate that the addition of rubber will improve the low temperature properties of asphalt cement, and that such modifications are necessary to reduce the tendency of asphaltic-paving materials to crack in cold climates and to increase the life cycle of the road.