Improved Rheological Properties of Polymer-Modified Asphalts
SourcePolymer modification dramatically changes the rheological properties and therefore the performance of asphalt cement. This study discusses conventional and new methods of specification testing for the polymeric elastic and tensile properties. Five asphalts were tested before and after polymer modification for penetration, viscosity, low temperature ductility, pen-vis numbers (PVN), and aging indices. Tensile strength, force ductility, toughness and tenacity, dropping ball, creep response, elastic recovery by ductilometer, torsional recovery, sliding plate rheometry, Dekker elastic recovery, and temperature susceptibility test methods are also examined. It is concluded that current asphalt cement specifications should be supplemented with tests for tensile strength and elastic recovery if the relative performance properties of polymerized asphalt cements are to be compared.