ABSTRACT VISCOELASTIC CHARACTERIZATION OF RUBBER ADDITIVE ASPHALT

This study investigated the effects of rubber modi-fication on the creep, relaxation, and fracture response of sand asphalt mixtures. Results of tests indicate that rubber modification improves the resistance of sand asphalt mixtures to creep under constant load. Relaxation moduli of modified mixes were found to be higher than unmodified mixes at all temperatures tested. Rubber modification was found to reduce the temperature susceptibility of sand as-phalt mixtures. The time-temperature superposition princi-ple was applied to creep and relaxation data taken at dif-ferent temperatures and master creep and relaxation curves were constructed. Results of impact and notched beam tests indicate that rubber modification improves the resistance of sand asphalt mixtures to brittle fracture at low temper-atures