Self-Healing Property of Ultra-Thin Wearing Courses by Induction Heating

Ultra-thin wearing course (UTWC) has been developed in pavement preventive maintenance for many years. However, how to prolong the service life of UTWC still requires further research. This study introduced AC-5 and SMA-5 asphalt mixtures, which can be induction heated. Steel fiber and steel slag were used in the mixtures as additives. Marshall Stability and induction heating property of mixtures were characterized. In addition, self-healing property of UTWC materials had been emphatically conducted. Adding steel fiber in mixtures led to higher Marshall Stability and lower flow value, while steel slag generally showed a negative effect. Induction heating property showed a positive relationship with the additives. Induction heating time was positively correlated to the healing ratio of the mixtures. Induction heating on the mixtures could recover the strength of mixtures to a certain degree. Mixtures with more steel fiber showed a higher healing ratio. Basalt-steel slag based mixtures showed better healing ratios than the basalt based mixtures. The healing ratios of mixtures illustrated a decreasing tendency as the healing cycle increased.