Abstract Manager

One of the best ways to manage the performance lifespan of asphalt road surfaces is to test recovered binder for acceptance during construction. In the late 1990s, acceptance specifications advanced from using empirical methods, such as penetration and viscosity on unaged binder in the Canadian General Standards Board (CGSB) specification of 1990 to Superpave™ rheology-based tests on unaged and laboratory-aged residue. In the early 2000s, Ontario agencies realized that poor-quality binder was responsible for premature and excessive cracking of road surfaces, after which enhanced aging, rheological and failure tests for unaged and recovered material were developed and implemented. This study correlates pavement service lives in Durham Region with recovered binder properties. Service lives to a pavement condition index (PCI) of 50 percent – which had decreased by about 66 percent since 1980 – bounced back immediately after the 2015 implementation of the double-edge-notched tension (DENT, AASHTO T 405) and extended bending beam rheometer (EBBR, AASHTO T 406) protocols for the acceptance of recovered binder. Both protocols favor the use of superior quality Alberta and Venezuela binders that are low in wax and contain a moderate amount of asphaltenes. Today, proper designs based on EBBR grade and grade loss in conjunction with DENT critical crack tip opening displacement (CTOD) have restored pavement service lives from 11 years in 2013 to their former 30-35 years in 2020.