Induced heating-healing of conductive asphalt concrete as a sustainable repairing technique: A review

Induced heating-healing of asphalt concrete is rapidly emerging as an innovative repairing technique in pavement engineering. In this method, asphalt concrete is heated using the external electromagnetic field. As a result, the viscosity of the asphalt binder decreases, leading to the movement of the asphalt binder through the cracks and healing them. Researchers have been intensively investigating this technique as a potential practical method to heal the cracks and extend the service life of asphalt concrete and pavement. This review paper itemizes the applications of induced heating in pavement engineering. The induced healing, as the predominant application, was compared against the self-healing mechanism in asphalt concrete. Different types of heating sources and their effects on induced heating-healing of asphalt concrete were investigated. Different types of conductive additives (i.e., fiber, powder, and granular) are utilized to enhance the induced heating-healing efficiency. This study covers the influence of conductive additive type on the rate of induced heating-healing, thermal conductivity, heat transfer, temperature distributions, and mechanical characteristics of asphalt concrete. Besides, the effects of different parameters (i.e., mixture components, aggregate gradation and type, specimen dimension, breaking temperature, crack configuration, mechanical damage, aging, moisture/freeze-thaw damage) on the induced heating-healing process in asphalt concrete were introduced and discussed in detail. Afterward, the sustainability aspects of the induced heating-healing technique (i.e., cost, greenhouse gas emission, and energy consumption) were investigated and compared with existing asphalt concrete repairing methods. Finally, the existing challenges regarding the induced heating-healing technique and suggestions for future studies were presented