Characterization of chloroprene rubber-modified asphalt binders

Abstract

Despite being one of the potential candidates for a suitable elastomeric additive to modify asphalt binders, there is a lack of research on using chloroprene rubber (CR). This study evaluates the suitability of using CR to enhance asphalt binder properties, particularly rutting and fatigue performances. Two different grades of asphalt binder (60/70 and 85/100 penetration grade) were modified by 3.5% and 7% CR to meet this end. The conventional physical, high-temperature storage stability, rotational viscosity (RV), dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), and linear amplitude sweep (LAS) tests were used to examine various features of the CR-modified asphalt binder. Results indicate that CR decreases penetration, ductility, and temperature susceptibility and increases softening point and viscosity of the asphalt binder. Additionally, the CR-modified binder can present acceptable pumpability and workability within the construction temperature range. However, the CR-modified binder has phase separation potential, particularly at high modification contents. Based on the results of MSCR and LAS tests, CR can effectively increase the rutting resistance, elastic recovery, and fatigue life of the asphalt binder. Nevertheless, the CR-modified asphalt binder’s rutting and fatigue behaviors depend mainly on the grade of the base asphalt binder.