New High-Temperature Binder Specification Using Multistress Creep and Recovery

Abstract

The objective of this study, conducted by the Federal Highway Administration, was the development of a PG binder test that is both performance-based and blind to modification type. The Multistress Creep and Recovery (MSCR) test was developed as a replacement for the existing AASHTO M-320 high-temperature binder test. The results from the MSCR test may also be used as an alternative to the various SHRP+ tests. In addition to characterizing fundamental properties, the MSCR is an easy-to-use performance-related test. Multiple binders both neat and polymer-modified were evaluated in the development of the new binder test to determine the high-temperature rutting property for binders. Equipment for testing of the binders was focused on the existing dynamic shear rheometer (DSR). This equipment has been widely accepted by highway agencies for use in determining rheological properties of binders in specifications. The DSR measures fundamental properties related to the stress strain response of viscoelastic materials and is ideally suited to evaluate asphalt binders.