Induction heating of electrically conductive porous asphalt concrete

In this research, an electrically conductive porous asphalt concrete, used for induction heating, was prepared by adding electrically conductive filler (steel fibers and steel wool) to the mixture. The main purpose of this paper is to examine the electrical conductivity and the indirect tensile strength of this conductive porous asphalt concrete and prove that it can be heated via induction heating. It was found that, to make porous asphalt concrete electrically conductive, long steel wool with small diameter is better than short steel fibers with bigger diameter. However, steel fibers with short length and big diameter have better strength reinforcement capability than steel wool with long length and small diameter. It was also proved that conductive porous asphalt concrete containing steel wool can be easily heated via induction heating. Finally, 10% (by volume of bitumen) of steel wool type 000 was proposed as an optimal content in porous asphalt concrete to obtain an optimal conductivity, a good induction heating rate and an acceptable indirect tensile strength. It is expected that the autogenous healing capacity of asphalt concrete will be enhanced with the increase of temperature during induction heating.