Revisions of the Superpave Binder Specifications To Include Modified Binders

摘要

The analysis of information collected from the surveys and the literature search of the NCHRP Project 9-10 (Superpave Protocols for Modified Binders) show a need for a new classification system that differnetiates between binders that can be considered as part of the PG-grading system and others that can not. A set of new or revised tests are needed to address characteristics that are typical of modified binders and that are not included in the current PG-grading. As part of the NCHRP project 9-10, the Particulate Additive Test (PAT) has been developed to determine the effective volume concentration of particulate additives. Also a new test to measure storage stability and potential for thermal degradations called the Laboratory Asphalt Stability Test (LAST) has been introduced. A modification of the RTFOT procedure to handle modified asphalts has also been developed and used with a wide variety of asphalts. A proposed expanded protocol is presented and a revised grading scheme is discussed.