Porous asphalt shows excellent performance in both noise reduction and water drainage. Although porous asphalt has these great qualities, its service life is much shorter (sometimes only half) compared to dense graded asphalt roads. Ravelling, which is the loss of aggregate particles from the surface layer, is the main damage mechanism of porous asphalt surface wearing courses. In this research, an induction healing approach (namely, activating the healing process of asphalt concrete through induction heating) was developed to enhance the durability of the porous asphalt roads. Steel fibres are added to a porous asphalt mixture to make it electrically conductive and suitable for induction heating. When micro cracks are expected to occur in the asphalt mastic of the pavement, the temperature of the mastic can be increased locally by induction heating of the steel fibres so that porous asphalt concrete can repair itself and close the cracks through the high temperature healing of the bitumen (diffusion and flow). The closure of micro cracks will prevent the formation of macro cracks. In such a way, ravelling can be avoided or delayed in the end.
To test the induction healing technology in a real porous asphalt road, a trial section was constructed on Dutch motorway A58 in December 2010. This trial section survived already five winters and is still in perfect shape. Experiments were done on cores drilled from the trial section and the results coincided with those on the laboratory made samples. A first heat treatment of the section with a large scale induction machine was performed in June 2014. Based on the laboratory experiments and field experiences it can be concluded that induction healing is a very good approach to enhance the durability of porous asphalt pavement. It is expected that the service life of porous asphalt can be doubled and will be similar to the service life of dense asphalt.