Assessment of Reflective Cracking Models for Asphalt Pavements

The research effort documented in this paper is directed toward identifying an analytical model that can be used to predict the resistance of HMA overlays to reflective cracking and predict their long-term performance. Various models were identified and three models were studied and compared in this research effort: 1) Virginia Tech Simplified Overlay Design Model, 2) Rubber Pavements Association (RPA) Overlay Design Model, 3) the New AASHTO model for Reflective Cracking. The identified models were assessed by the research team based on their ability to predict the performance of HMA overlays subjected to reflective cracking. An overlay design was conducted for three different HMA overlay mixes using the three identified overlay design methods. The overlay mixes were manufactured using different aggregate gradations from the Sloan pit in Southern Nevada and a PG76-22 polymer modified asphalt binder. The overlay was designed for 7,000,000 ESALs over the 20 years analysis period. Finally, a comparison was exerted among the various HMA overlay thicknesses required by each method and the material properties associated to such determination to accomplish the design traffic.