A comparison of the predicted performance of virgin and recycled mixes

The Marshall design method is the most commonly used method for the design of virgin and recycled mixes. However, the Marshall design procedure does not provide the field performance of the mix in terms of fatigue, rutting, thermal cracking, and moisture damage. The Asphalt Aggregate Mixture Analysis System (AAMAS) and the program called SUPERPAVE, developed in Strategic Highway Research Program, are two performance-based mix design methods that can address most forms of pavement distress. Although the AAMAS program was developed using virgin mixes, the AAMAS design criterion for this study was applied to recycled mixes. Specifically, the predicted performance of recycled mixes was compared with that of virgin mixes. In general, all of the mixes evaluated satisfied the AAMAS criteria. However, the results indicated that the fatigue resistance decreased as the recycling percentage increased. The recycled mixes had higher resistance to moisture damage when compared with virgin mixes.