Evaluation of the influence of induction factors (time and power), geometric characteristics and environmental conditions on the self-healing capability of warm mix asphalt

Despite the well-known environmental, technological, and economic benefits of warm mix asphalt (WMA), the decreased production temperature of WMA mixtures can cause reduced bitumen-aggregates adhesion, increasing the susceptibility of the mixtures to cracking. This study discusses the simultaneous use of warm mix asphalt and induction heating technologies to improve the self-healing capability of these mixtures in order to increase their performance and durability, which can lead in turn to prolonged pavement lifespan and lower maintenance and repair costs. The aim of this research is to evaluate the self-healing capability of conductive warm mix asphalt using induction heating. Asphalt samples with iron powder and activated carbon were tested using semi-circular bending (SCB) at 25°C and -16°C with notch lengths of 10 mm and 20 mm. Induction heating was performed with the use of power of 13.9 kW and 16.7 kW and heating time of 60, 90, and 120 seconds. Results indicated that increased power and heating time led to a higher healing index. Asphalt samples containing Sasobit at 25°C inductive heating time of 120 seconds and heating power of 16.7 kW attained a healing index of 88.5%, which indicates the optimal performance of the additive in medium temperatures. In low temperatures, asphalt samples containing ZycoTherm indicated a healing index of 60%, showing its higher efficiency in low temperatures. ZycoTherm performed better at low temperatures because of its anti-stripping properties, whereas Sasobit performed poorly at low temperatures because of its synthetic wax and high cold-sensitivity properties. The use of iron powder as an inductive agent demonstrated that inductive heating can serve as a viable healing method for asphalt pavements, contributing to the development of sustainable and eco-friendly road infrastructure.