Evaluation of Rutting and Cracking Resistance of Foamed Warm Mix Asphalt Containing RAP

Abstract

Significant efforts have been made in recent years to construct sustainable and environment-friendly transportation infrastructure. These efforts are targeted toward saving natural resources, conserving the environment and reducing energy consumption. The use of Warm Mix Asphalt (WMA) technologies and increased utilization of Reclaimed Asphalt Pavement (RAP) in asphalt mixes are widely practiced by the asphalt industry. In the present study, the rutting and cracking resistance of WMA mixes containing RAP were evaluated in the laboratory and compared with those of Hot Mix Asphalt (HMA) containing the same amount of RAP. To assess the rutting resistance, Hamburg Wheel Tracking (HWT) tests were performed. Fatigue cracking performance was evaluated using Semi Circular Bending (SCB) test and Indirect Tensile Strength (ITS) test. The HWT tests data indicated that for similar numbers of wheel passes, higher rut depths were observed in the WMA specimens compared to the HMA specimens. This difference became increasingly dominant with a higher number of passes. Also, the WMA specimens exhibited more moisture-induced damage potential as indicated by the presence of stripping inflection point than the HMA specimens, as expected. From SCB and ITS tests, it was concluded that the fatigue and cracking resistances of foamed WMA specimens containing RAP were similar to those of their HMA counterparts. The findings of this study are expected to evaluate the laboratory performance of foamed WMA containing RAP.