Sustainable Induction-Heatable Cold Patching Using Microwave and Reclaimed Asphalt Pavement

Patching is a common pavement treatment, and it is implemented using hot and cold process patching. Hot process patching is not an efficient implementation method because keeping asphalt temperature in long hauls is difficult, on-site mixing equipment is required, and transport costs are generally high. Moreover, hot process patching requires a significant amount of energy, so it is not an eco-friendly process. Although cold process patching significantly reduces the energy consumption of patching, its implementation reduces the patching quality. To this end, this study aimed to propose a new cold process patching using induction heating. Furthermore, this study attempted to apply waste materials in the proposed mixtures to preserve the environment. Accordingly, high percentages of reclaimed asphalt pavement (RAP) were used in the proposed mixture. Since induction heating was applied in the introduced patching method, two waste materials, including steel slag and electronic waste, were utilized in the mixtures to enhance the sensitivity to electromagnetic radiation. Moreover, different experimental tests were conducted to evaluate the mixtures' mechanical properties. Ultimately, gray relational analysis was performed to assess the proposed mixtures' sustainability. The results indicated that using steel slag and electronic waste as conductive materials could considerably reduce the heating time to raise the fabricated mixtures' temperature. Moreover, replacing the Neat mixture with the proposed asphalt mixtures containing the waste materials significantly reduced the unit price, greenhouse gas emission, energy consumption, and raw material utilization.