WU W L,PENG J L,LI Z,et al．Numerical simulation of microwave thermal induction in asphalt mixtures［J］.Journal of Henan Polytechnic University( Natural Science)

doi:10.16186/j.cnki.1673-9787.2023110060.

doi:10.16186/j.cnki.1673-9787.2023110060

Received：2023-11-30

Revised：2024-02-22

Online：2024-05-21

Numerical simulation of microwave thermal induction in asphalt mixtures (Online)

WU Wenliang, PENG Junlin, LI Zhi

（School of Civil Engineering & Transportation, South China University of Technology,Guangzhou 510641,Guangdong,China）

Abstract: In engineering applications, microwave thermal induction techniques were measured and evaluated based solely on the surface temperature of the structure. Objectives To address the problem of the unknown mechanism of microwave action on the interior, Methods COMSOL finite element simulation was adopted in this study. The electromagnetic parameters of the asphalt mixture as a whole are calculated from the electromagnetic parameters of each material, and the electromagnetic-thermal coupling finite element numerical analysis is carried out. This method can analyze the electric field strength distribution law of microwave inside the square specimen and infer the induction mechanism of microwave on the temperature change inside the asphalt pavement structure. Combined with the square asphalt mixture specimen in the microwave thermal induced environment specimen surface temperature changes by the induction time changes are verified. Finally, it is clarified that the internal temperature of asphalt mixtures with different gradations is uniformly distributed under the microwave thermal induction environment.Ｒesults The wave-absorbing performance of different minerals can be evaluated by their ability to dissipate energy, and the calculation shows that diabase has better wave-absorbing performance than other stone materials under microwave thermal induced action. After finite element numerical simulation, the internal structure of all grades of diabase asphalt mixtures was heated for 200s under the dynamic microwave thermal induced environment, and the overall average temperature of the structure reached more than 80℃, which meets the healing temperature requirements of small cracks inside the mixtures. Conclusions The asphalt mixture with pyroxene as the skeleton can be warmed up to 80°C within 200s of microwave thermal induction, which meets the healing requirements of the internal structural cracks, and can more efficiently utilize the microwave thermal-induced healing technology to prevent the cracks in the asphalt mixture from developing into functional diseases such as potholes and looseness.

Key words: microwave thermal induction;numerical simulation;COMSOL;diabase;induction mechanism