Characterization of the material from the induction healing porous asphalt concrete trial section

Abstract

An induction healing approach was developed to increase the service life of porous asphalt wearing course. Steel wool fibers were mixed in the asphalt mixtures, and then induction heating was applied to heat up the localized steel wool fibers in asphalt mixtures when damage is expected. As a result of induction heating, possible cracks and damages inside porous asphalt can be healed. The objective of this paper is to characterize the field obtained material from an induction healing porous asphalt trial section with laboratory experiments. Heating speed of the field cores was first measured with an infrared camera. It was found that these cores with steel wool can be heated with induction energy. Then, the particle loss value, indirect tensile strength, water sensitivity and nano indentation modulus of the field cores were studied. The results indicate that the addition of steel wool improves the particle loss resistance and ductility of the porous asphalt concrete cores. The mortar phase in porous asphalt core with steel wool shows higher indentation modulus than that in the plain core. These findings imply that steel wool can increase the ravelling resistance of porous asphalt concrete. Finally, the fatigue life extension parameter in four point bending test was applied to investigate the healing potential of this porous asphalt mixture with and without induction heating. The fatigue life of the beams can be greatly extended with induction heating. It was also found that the aged beams can heal much more and faster with induction heating than that with natural healing. Based on these findings, it is expected that the durability of porous asphalt pavement will be improved by the reinforcement of steel wool and induction healing.