Evaluation the Effects of Activated Carbon on Induced Healing of Laboratory Aged Mixes under Microwave Radiation

Aging phenomenon affects pavement performance that results in reduced flexibility of the pavement. Aging can cause asphalt binder stiffness in asphalt mixes and increases the risk of cracking. Cracks can be healed by the induction heating method. The ability of asphalt binder in flowing and filling cracks plays a dominant role in the induced healing of asphalt mixes. With this regard, activated carbon (AC) is added to asphalt concrete in order to enhance the electromagnetic radiation absorption of mixes. In order to apply age conditioning, both the control and modified asphalt concrete samples were kept in oven for 5 days at 85℃. It was found that heating rate of activated carbon modified asphalt mixes is 55 percent greater than control mixes. From the results of this study, effects of asphalt concrete aging was determined by induced healing index. In addition, repeated breaking-healing cycles were applied through indirect tensile testing to investigate the induced healing properties of asphalt mixes. This was through peak load and fracture energy criteria. In addition, effect of sample dimensions on heating rate and damage level were investigated on induced healing index of asphalt concrete. It can be concluded that increased asphalt concrete aging and increased breaking-healing cycles resulted in decreased induced healing index. Result reveals that combination effects of aging and breaking healing cycles resulted in 48 percent reduction in healing index. In addition, testing results confirmed that AC as a conductive component has potential of induction heating healing and increasing aging resistance of asphalt mixes.