Induction heating of asphalt mastic for crack control

Asphalt mastic is a self-healing material and it has the potential to close internal cracks by itself. In this study, an induction healing approach is developed to increase the self-healing capacity of asphalt mastic. Conductive additives are added to asphalt mastic to make it electrically conductive and suitable for induction heating. When micro-cracks are expected to occur in asphalt mastic, induction heating can be to improve the self-healing ability of asphalt mastic to close the cracks. This paper investigates the induction heating speed, bending strength and induction healing rate of asphalt mastic with different conductive additives. It was observed that asphalt mastic that contained steel wool or steel fiber can be rapidly heated using induction energy. Adding steel wool or steel fiber to asphalt mastic also increases its bending strength. Finally, the fractured asphalt mastic beams that contain steel wool and steel fiber can regain their bending strength to that of fresh reference samples with induction heating. Cracks were observed to disappear during induction heating. Based on these results, it is concluded that induction heating/healing can be used to close cracks in asphalt mastic. (C) 2012 Elsevier Ltd. All rights reserved.