工业微波照射下混凝土砂浆-骨料界面力学性能与多场效应数值分析

Numerical Analysis on Mechanical Properties and Multi-field Effects of Concrete Mortar-aggregate Interface under Industrial Microwave Irradiation

针对微波加热特点,采用Comsol Multiphysics数值软件建立了含界面层的砂浆-骨料模型,分析了模型内部电磁场、温度场、应力场的分布情况,得出了砂浆-骨料界面处热力学性能的变化规律及多物理场耦合作用下界面过渡区的微波响应。通过与微波照射砂浆-骨料模型实验对比,验证了数值分析的可靠性。研究结果表明,微波照射后会在界面过渡区域产生很大的温度梯度和热应力,更高的功率和更长的加热时间能使温度梯度、拉应力和压应力变大,从而更有利于砂浆与骨料的界面剥离,实现粗骨料的回收。分析了同一微波能量层级不同照射模式下,试件的热力响应情况。

Based on microwave heating characteristics,Comsol Multiphysics numerical software was used to establish a mortar-aggregate model with an interface transition zone.The distribution of electromagnetic fields,temperature fields and stress fields inside the model was analyzed,as well as the thermos-mechanics characteristics of the mortar-aggregate interface.The microwave response of the interface transition zone under the coupling of multiple physical fields were obtained.The reliability of the numerical analysis is verified by comparing with the microwave irradiation experiment.The results show that microwave irradiation leads to a considerable temperature gradient and thermal stress in the interface transition zone.Higher power and longer heating time can enhance the temperature gradient,reduce the tensile stress and compressive stress of interface,making the interface between the mortar and the aggregate more favourable to the recovery of the coarse aggregate.This article also analyzes the thermal response of the specimen under different irradiation modes at the same microwave energy level.