Abstract: Asphalt undergoes rheological behavior at high temperatures, which enables it to fill cracks in the mixture to achieve self-healing. The use of microwave-induced heating will accelerate its self-healing process; however, asphalt mixtures have slow heating rates and uneven temperature distribution under microwave action. Therefore, ferrite and silicon carbide powder were added into asphalt according to a certain proportion, and research on the effect of microwave on the heating law of the mixture was carried out by numerical simulation and indoor test respectively. The research results show that ferrite and silicon carbide affect both the heating rate and temperature uniformity of the mixture. When the mixing ratio of ferrite: silicon carbide is 6∶4, the asphalt mixture has the best warming performance, and the warming rate is 0.6 ℃/s. Under the action of microwave, a temperature concentration zone will appear at the center of the specimen, with a temperature of 173 ℃ and a maximum temperature difference of 103 ℃ between the inside and outside. The mixture undergoes heat conduction during microwave heating, and its heat transfer rate is inversely proportional to the temperature difference, with an average rate of 0.95 ℃/s.

Key words: road engineering; modified asphalt; asphalt mixture; microwave heating; numerical simulation; warming mechanism

摘要： 沥青在高温时会产生流变现象，这一特性使得其能够填补混合料中的裂缝而实现自愈合；微波诱导加热则会加速其自愈合过程，但沥青混合料在微波作用下存在升温速度慢以及温度分布不均等缺陷。基于此，将铁氧体和碳化硅粉末按一定比例添加到沥青中，分别采取数值模拟与室内试验相结合方法对混合料在微波作用下的升温性能影响展开研究。研究结果表明：铁氧体与碳化硅对混合料的升温速率与温度均匀性均有影响，当铁氧体：碳化硅的掺配比例为6∶4时，沥青混合料的升温性能最佳，此时升温速度为0.6 ℃/s；在微波作用下，试件中心会出现温度集中区，其温度为173 ℃，内外温度差最大为103 ℃；混合料在微波升温的同时会伴随着热传导现象，其传热速率与温差成反比，平均速率为0.95 ℃/s。

关键词: 道路工程；改性沥青；沥青混合料；微波加热；数值模拟；升温机理