Nonrecoverable Compliance and Recovery Behavior of Polymer-Modified and Reclaimed Asphalt Pavement–Modified Binders in Arkansas

Abstract

Abstract For quality assurance and quality control purposes, suppliers and users of asphalt binders follow the widely used dynamic shear rheometer (DSR) test method (AASHTO T 315, Standard Method of Test for Determining the Rheological Properties of Asphalt Binder Using a Dynamic Shear Rheometer (DSR)) to capture viscoelastic properties of polymer-modified binders (PMBs) and reclaimed asphalt pavement (RAP)–modified binders even though it is designed for unmodified asphalt binders. AASHTO T 315 is inadequate to characterize modified binders because of the relatively small impact of the phase angle and strain levels on the rutting and fatigue factors, respectively. The recently approved multiple stress creep recovery (MSCR) test (AASHTO T 350, Standard Method of Test for Multiple Stress Creep Recovery (MSCR) Test of Asphalt Binder Using a Dynamic Shear Rheometer (DSR)) results can better relate the laboratory-based and field rutting of PMBs and additive-modified binders. In the current study, Superpave and MSCR tests were performed to evaluate viscoelastic properties of selected asphalt binders certified in Arkansas. A total of 32 binders were tested in the laboratory. Among these, 8 were unmodified binders, 18 were PMBs, and 6 were RAP-modified binders. The nonrecoverable compliance and MSCR percent recovery data of tested binders were analyzed for the grading purpose and establishing the MSCR percent recovery criteria for local service temperature and traffic conditions. The developed guidelines are expected to be helpful for transportation agencies in Arkansas to adopt the MSCR test method in their quality control processes.