RHEOLOGICAL PROPERTIES OF RUBBERR-MODIFIED ASPHALT

The performance of rubber (from used tires) as an asphalt cement modif ier was evaluated by performing experiments on the shear-flow properti es and creep-rupture behavior of modified asphalt cements. Results ind icate that various asphalt/rubber samples exhibit shear-thickening, Ne wtonian, 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. Th ese increases indicate that the addition of rubber will improve the lo w temperature properties of asphalt cement, and that such modification s are necessary to reduce the tendency of asphaltic-paving materials t o crack in cold climates and to increase the life cycle of the road.