Assessment of induction heating in the performance of porous asphalt mixtures

This paper presents a study of the healing performance of a porous asphalt (PA) mixture heated by induction. The influence of incorporating two sorts of metallic particles, steel wool fibre and steel grit, into the porous asphalt was assessed in terms of the mechanical performance of the mixture. In addition to the volumetric and mechanical tests performed, the effect of applying the healing treatment to the PA mixture was assessed. Thus, the conditions in which the fatigue resistance was increased or the particle loss was reduced were defined, according to the fatigue and Cantabro test, respectively. According to the results, the selection of the type of metallic particle is more an economic than a performance decision. Concerning the healing treatment, the methodology differs depending on the type of failure that is addressed. While for increasing the fatigue resistance, the induction heating should be applied when the modulus is closed to half of its initial value, when ravelling is the dominant failure, periodically heating the surface via induction from an earlier stage, when the ravelling starts, provides the best results. In both cases, a significant increase of the PA mixture durability has been observed