Rheological Properties of Silicon Carbide Powder-Modified Asphalt Mastic and Microwave Heating Application

Silicon carbide powder, as a high-performance microwave-absorbing material, can be used for self-healing of microcracks in asphalt pavements, which is promising to lift the limitation of the application of microwave heating technology in road maintenance. The primary adhesive skeleton in asphalt mixtures, known as asphalt mastic, plays a crucial role in determining the overall properties of the mixtures. In this study, conventional limestone asphalt mastic and silicon carbide powder asphalt mastic with high microwave absorption capacity were designed and prepared using varying filler-bitumen ratio (FBR). The performance and properties of the filler were tested by XRD and SEM. The microwave heating test and DSR test were carried out on the fillers and asphalt mastics to study the microwave heating properties and rheological properties. Based on rheological properties, initial and optimal temperatures for self-healing are determined. The results show that the addition of silicon carbide powder had a significant increase in the initial self-healing temperature of asphalt mastic, but had little effect on the optimal self-healing temperature. Moreover, the difference in temperature to achieve the same rutting factor (1 or 10 kPa) is not significant. These indicate that it is feasible to consider silicon carbide powder as a filler in asphalt mixtures from the point of view of self-healing temperature. The exceptional microwave absorption capabilities of silicon carbide powder boost the microwave absorption of silicon carbide asphalt mastic, significantly reducing the time required to reach the necessary self-healing temperature. Overall, silicon carbide powder can be used in road engineering to enhance the microwave absorption properties of asphalt mixtures, which advances the application of microwave maintenance technology in road engineering.