Influence of microwave heating on the swelling properties of expansive soil in Hefei

The swelling deformation of expansive soil after immersion often lead to engineering disasters. In this paper, the experiments on the swelling properties of expansive soil in Hefei after microwave heating have been carried out. The results show that, the soil samples change from fine particles to coarse particles after microwave heating. With the increase of microwave heating time, the specific gravity of soil samples first increases and then decreases, while the liquid and plastic limit continue to decrease. In addition, microwave heating significantly affects the swelling behaviors of soil samples. With the increase of microwave heating time, both the free swelling ratio and vertical free swelling strain decrease. In the process of microwave heating, there are a series of physical and chemical changes in expansive soil, such as the water escaping from the interlayer structure of clay minerals, the transformation and decomposition of material components, which significantly changes the physical and mechanical properties of expansive soil.