Comparison of Parameters from a New MSCR Approach with Classical MSCR and LAS Parameters for Simplified Binder Selection Available to Purchase

Fatigue and rutting are the most studied pavement distresses. There are different material testing protocols whose compatibilities must be systematically analyzed for proper material selection and performance prediction. They usually focus on either rutting or on the fatigue susceptibility of the materials. In asphalt binders, the idea is to assess material behavior that may relate to the behavior of the corresponding asphalt mixtures in the field. However, a new multiple stress creep recovery (MSCR) approach suggests the use of an index obtained from a modified testing protocol (B-index) that may relate to fatigue. This paper compares the parameters obtained by a new MSCR test methodology, which gives parameters that may also relate to fatigue, with parameters from the standard MSCR test and linear amplitude sweep (LAS) test to analyze both binder permanent deformation and fatigue cracking. This study was conducted with a PG (Performance Grade) 64-28 neat binder and three levels of styrene-butadiene-styrene (SBS) modification by weight of the binder: 2 %, 3 %, and 4 %. The results from the new MSCR protocol indicates that the higher the modifier content, the higher the fatigue resistance based on the B-index. This finding is also supported by the LAS parameters, fatigue area factor of binder (FAFB) and af (fracture length). The study concluded that a preliminary choice based on MSCR’s B-index might overcome time-consuming testing.