NCAT Report 18-01: Material Selection Guidance for Asphalt Pavement Design

Innovation and sustainability have been hallmarks of the asphalt pavement industry for many years. Technologies such as warm mix asphalt (WMA), recycled asphalt shingles (RAS), reclaimed asphalt pavement (RAP), recycled tire rubber (RTR), stone matrix asphalt (SMA), and cold recycled (CR) mixtures offer economic, engineering, and environmental advantages when their use in structural pavement design is carefully considered to arrive at optimized structures. A primary challenge to this effort has been that these technologies often outpace the structural design procedures that may rely solely on more conventional materials and performance characterization.

The objective of this investigation was to provide guidance for flexible pavement design methods to arrive at optimized pavement structures when innovative and sustainable materials are used, and to identify the challenges when trying to incorporate these materials. This investigation also provides a basic understanding of different materials and technologies, mix design considerations, material properties, performance, and possible applications.