Performance properties of rubberized stone matrix asphalt mixtures produced through different processes

The study investigated the dynamic modulus, rutting resistance, moisture susceptibility and fatigue resistance of rubberized Stone Matrix Asphalt (SMA) through laboratory performance tests. Rubberized SMA mixes were produced by three processes: the dry process, the wet process and the terminal in the laboratory. For comparison purposes, SMA mixtures containing styrene-butadiene-styrene (SBS) modified binder and virgin asphalt of PG 67-22 were also evaluated and compared to rubberized SMA. Dynamic modulus and direct tension fatigue tests were performed using the Asphalt Mixture Performance Tester (AMPT) system. Rutting resistance and moisture susceptibility were analyzed by Hamburg wheel tracking test using asphalt pavement analyzer (APA). The results showed that: (1) the incorporation of CRM improved the high temperature dynamic modulus, the resistance to rutting and fatigue life of SMA mixes. (2) The introduction processes of CRM (dry process and wet process) may have effect on the high temperature dynamic modulus and rutting resistance, while no significant influence on the moisture susceptibility and fatigue life. (3) The use of combination of SBS and CRM in the terminal SMA significantly improved the resistance to rutting and fatigue cracking. (4) The rubberized SMA with 10% CRM had the lower performance properties than SBS SMA, regardless of the dry process or the wet process. (C) Published by Elsevier Ltd.