On electro-thermal crack healing of conductive asphalt concrete mixture

This study investigates the influence of CNT contents (0 wt%–1.5 wt%) on the electro-thermal crack healing of asphalt concrete incorporating 0.3 wt% CF. Three-point bending tests, electrical resistance measurements, temperature field monitoring, and SEM analysis were conducted. Optimal healing was achieved with 0.5wt% CNTs at 50– for 15 min,exhibiting healing indices of 80.2% (ultimate load) and 70.3% (fracture energy), with the effective thermal energy ratio reaching 68.1%. Polynomial fitting indicated peak energy efficiency at this dosage. SEM observations indicate that 0.5 wt% CNTs constructed a uniform ‘point-line' synergistic network, whereas literature-supported hypotheses suggest that excessive dosages induced agglomeration and thermal barriers. These findings quantitatively elucidate the synergistic mechanism between conductive network topology and crack healing.