Induction Healing of Porous Asphalt

Abstract

Research on the induction healing of porous asphalt is summarized. Steel wool is added to porous asphalt concrete to make it electrically conductive and suitable for induction heating. When microcracks occur in the material, an induction generator is used to heat the material to close the cracks by the high-temperature self-healing of bitumen. The electrical resistance and induction heating speed of porous asphalt concrete reinforced with steel wool are examined. Porous asphalt concrete containing steel wool is found to be electrically conductive and can be heated with induction energy. The mechanical properties of this porous asphalt are also studied. Steel wool can reinforce porous asphalt concrete by increasing its strength, particle loss (raveling) resistance, and fatigue resistance. Furthermore, the induction healing effect of this porous asphalt concrete reinforced with steel wool is evaluated. It is proved that the fatigue life of induction-healing porous asphalt can be extended significantly by the application of induction heating. It is also found that the optimal heating temperature for the best healing effect is 85°C. These findings indicate that the self-healing potential of porous asphalt concrete and the durability of porous asphalt pavement are improved by induction heating. Finally, a test section was paved on the Dutch A58 motorway with a porous asphalt layer containing steel wool. Because asphalt concrete exhibits better self-healing at higher temperatures, the future for the application of induction-healing porous asphalt concrete appears to be promising.