Effects of Aging and Rest Periods on the Self-Healing Properties of Asphalt Mixtures

Aging of asphalt mixtures is one of the main causes of reduced durability and performance in flexible pavements. The self-healing ability of asphalt materials plays an important role in extending their service life. This study examines the impact of short-term and long-term aging, using two standard methods (R۳۰ and NCHRP), as well as the influence of different rest periods on the self-healing capacity of asphalt mixtures. Specimens were prepared with PG ۶۴-۱۶ binder and siliceous aggregates, and self-healing was assessed using three indicators: stiffness ratio difference, fatigue life ratio, and failure rate. The results show that longer rest periods significantly improve self-healing indices. Samples aged with the R۳۰ method generally performed better than those aged with the NCHRP method, while unaged samples consistently exhibited the highest self-healing potential. The findings suggest that employing multiple indices provides a more complete picture of asphalt mixture behavior, and systematic comparison of aging methods can serve as a valuable guide for optimizing materials and designing long life pavements.

کلیدواژه ها:

Asphalt mixtures ، aging ، Self-healing ، Rest Periods ، Pavement Performance