Study on the Self-healing Behavior of Silicon Carbide Asphalt Mastic and Determination of the Optimal Dosage

Self-healing technology has great advantages in prolonging the service life of asphalt pavement. Understanding the development of the self-healing behavior of bituminous material and enhancingits self-healing capacity are the prerequisite for its application in engineering. Microwave heating is an effective method for accelerating the healing of cracks in wave-absorbing asphalt materials. In this work, silicon carbide was used as the absorbing material to prepare self-healing asphalt mastic with filler-bitumen ratio of 0.9, which can improve the absorbing property and road performance of asphalt mastic. The effects of silicon carbide on rheological, mechanical and self-healing properties of asphalt were analyzed microscopically, and the heating behavior under microwave irradiation. The results show that the initial temperature of self-healing, the optimum temperature of self-healing and the elastic modulus of asphalt mastic show a ‘bimodal curve’ with the increase of silicon carbide replacement ratio. The reason for this is the change in particle gradation of the silicon carbide - limestone powder composite filler, which forms a different interfacial structure resulting in a change in the properties of the asphalt mastic. Based on the above parameters, the optimal volume replacement ratio of 40% is proposed. In addition, microwave test also shows that the optimal replacement dosage is 40vol%. Under the filler- bitumen ratio of 0.9, considering the road performance and self-healing property, the optimal replacement dosage of silicon is 40vol%. The results can provide theoretical reference for the development and design of silicon carbide absorbing asphalt material. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.