New Insights Into Freezing Behavior of Saturated and Air-Entrained Porous Media via a Micromechanics-Based Thermo-Hydro-Mechanical Model

A micromechanics-based thermo-hydro-mechanical model for capturing the freezing behavior of porous media is devised, where a microstructure-dependent constitutive relation, thermo-hydro-mechanical conditions, and the origin of freezing deformation are comprehensively considered. A micromechanical upscaling approach is proposed to improve the physical understanding of the freezing behavior of porous media. Comparisons against experimental and theoretical results suggest that the present model is a reliable means to predict the freezing deformation of saturated and air-entrained porous media. The results show that the freezing deformation induced by the hydraulic pressure strongly depends on the boundary and air-entrained conditions, and the undercooling phenomenon can be captured well. Moreover, the magnitude of surface energy (0-8 MPa) is in the ascending order of saturated undrained, drained, and air-entrained conditions. The proposed model sheds light on the quantitative effects of freezing rate, liquid water transfer, and pore shape on the freezing deformation of porous media, which can provide insights into the freezing resistance mechanism of porous media.