Sustainable microwave-heating healing asphalt concrete incorporating functional aggregates and waste ferrite

Self-healing asphalt concrete can reduce maintenance costs and extend the lifespan of asphalt pavements. To advance the self-healing technique, this paper proposes a pioneering approach involving a dual microwave-heating pathway to produce a type of microwave-heating healing asphalt concrete that can offer better self-healing ability. Throughout the healing process, limestone powder filler is substituted with a waste microwave-sensitivity ferrite powder filler, primarily remedying microcracks within asphalt mastic. Additionally, the conventional aggregate is substituted with a functional aggregate to establish a three-dimensional thermally conductive framework under microwave radiation, effectively repairing microcracks at the aggregate-asphalt interface. The experimental findings reveal that the optimized formulation retains a substantial healing index of 70% after undergoing three damage-healing-damage cycles, with a reduction of 4% in crack resistance. These findings strongly endorse the practical application of functional aggregates and waste ferrite in asphalt concrete, resulting in enhanced maintenance efficiency and fostering the sustainability of the pavement system.