Exploring directional energy conversion behavior of electromagnetic-based multifunctional asphalt pavement

Electromagnetic-based multifunctional asphalt pavement (EM-MAP) containing conductive metals can be heated to the pavement temperature required for self-healing, snow-melting and hole repair through energy conversion. However, there is a serious waste of magnetic energy during the energy conversion process. In this case, a novel EM-MAP was designed to enhance conversion efficiency by solving the waste of magnetic energy, and the random dispersed heat source numerical model was established to analyze the novel EM-MAP directional energy conversion behavior. The effects of the content of the conductive metals (S), heating frequency (f), power (P) and time (t) on the energy conversion efficiency were investigated by the numerical model. Results show that the energy conversion efficiency for novel EM-MAP is increased up to 49.7%. In addition, based on the analysis of the economic benefits of unit pavement, the optimal operation scheme (S: 6%, P: 6 kW and f: 40 kHz) was recommended. Finally, the comparison between the laboratory testing results of the previous study and this study shows that the novel EM-MAP can significantly improve heating efficiency, and the maximum surface temperature of the conventional and novel EM-MAP using the optimal operation scheme is 76.8 °C and 93.5 °C respectively in the on-site heating test.