Induction heating and induced healing evaluation of the asphalt concretes incorporating conductive aggregates exposed to microwave radiation

Abstract

This study investigates the application of aggregate-based conductive additives, including steel slag, Iron slag, and ferrosilicon, in asphalt concretes for induction heating and induced healing purposes. The research focuses on evaluating the mechanical properties, induction heating capabilities, induced crack healing, environmental impacts, and cost of various conductive asphalt concretes. The Gray Relation Analysis (GRA) technique is then employed to determine the sustainability ranking of these mixtures based on the aforementioned criteria. The mechanical properties of the asphalt concretes were evaluated through the Indirect tensile strength at intermediate temperature and semi-circular bending tests at intermediate and low temperatures. The homogeneous induction heating rate of the mixtures was also examined. Additionally, the healing indices for the breaking-healing cycles were investigated. The environmental impacts and fabrication cost of conductive asphalt concretes were compared to identify the most sustainable conductive mixture with optimal performance and durability. The results demonstrate that the addition of aggregate-based conductive additives significantly improves the mechanical properties and homogeneous heating rates under microwave radiation. Furthermore, the conducted tests indicate that the introduced conductive asphalt concretes possess the ability to heal and restore their mechanical properties after damage or cracking. Moreover, the sustainability analysis reveals that the mixtures incorporating steel slag, especially asphalt concrete incorporating fine steel slag, are more sustainable and cost-effective compared to conventional asphalt mixtures. These findings provide valuable insights for road infrastructure and pavement design, aiming to incorporate innovative and environmentally friendly materials and methods to enhance the healing competencies and performance of flexible pavements.