Description
Due to increasing concerns regarding the availability of SBS polymer, a number of alternative options have been proposed to provide polymer modifiers for the asphalt binder industry. This paper focuses on the evaluation of six specific polymer modified binders: SBS modified binder, Reacted ethylene terpolymer (Elvaloy), Ethyl vinyl acetate (EVA), Asphalt Rubber, Hybrid (SBS and CRM) binder, and polyphosphoric acid (PPA). The goal of this project was to evaluate the various modified binders with respect to binder properties as determined by the Multiple Stress Creep Recovery (MSCR) test. The MSCR test was developed as a method to determine the performance of polymer modified binders, as opposed to simply detecting the presence of a modifier. The results indicated that wet process style asphalt rubber and SBS tended to yield the best results; however, hybrid SBS-CRM binder also exhibited good MSCR properties.