Recovery capacity of electroconductive asphalt mortars under the influence of magnetic fields

Abstract

The self-healing capacity of electroconductive asphalt materials can be enhanced by the use of induction heating. The highest enhancement of this self-healing capacity is produced in the early stages of the fatigue life of the material. During the early stages of the fatigue life, micro-cracks appear in the mastics/mortars that compose the asphalt mixture. In this sense, by the use of micromechanics, it could be possible to study the mastics/mortars to characterize the healing performance of asphalt mixtures under induction heating treatments. This study evaluates the recovery capacity of electroconductive asphalt mortars (EM), after multiple applications of induction heating and rest periods. In order to use a representation of materials that can be produced on-site, the EM were manufactured with the smallest sizes of metallic fibres obtained from the recycling process of vehicle tires at the end of their useful life. Results showed that half of the recovery capacity of the EM was produced by the effect of induction heating and the remainder by the effect of rest periods. This recovery capacity generates an extension in the fatigue life of the EM, which along with the use of a high asphalt content (higher than 7%) and fine aggregates (less than 9.5 mm), provides the conditions to use the EM in the construction of interlayer systems. The use of EM as interlayer systems, additionally to delay the reflection of cracks in the surface layers of the pavement, seems to represent a safe strategy to introduce their use on-site.