Fracture and mechanical properties of water-based foam warm mix asphalt containing reclaimed asphalt pavement

The present work was drawn aimed at addressing the role of RAP materials on fracture and mechanical properties of foam WMA mixes. Fracture testing in the geometry of SCB and Pull-Off adhesion tests were performed coupled with mechanical testing in order to address cracking failure, internal bonding characteristics, and moisture susceptibility of asphalt mixes. The results of SCB testing were assessed through Flexibility Index, fracture energy, and Cracking Resistance Index of foam WMA mixes. Results of Pull-Off testing showed that increased RAP materials resulted in reduced adhesion between foam bitumen and aggregate particles. This indicates the adverse impact of excessive RAP contents (i.e., at 70%) in mixes on flexibility of foam-WMA mixes. These were in agreement with the results of fracture testing. In contrast, the application of lower amounts of RAP (i.e., 30 and 50%) resulted in increased resistance of foam-WMA mixes against crack propagation. (C) 2020 Published by Elsevier Ltd.