A study of the behaviors of cement-based materials subject to freezing

The freezing behavior of cement-based materials is studied in this paper. The freezing-related pore structure is investigated, the fundamental relationship between liquid water saturation degree and freezing temperature is established and the material cryo-deformation is given through poroelastic approach. The effective pressure from freezing is divided into contributions of hydraulic pressure by viscous water flow and pore crystallization pressure by phase change as well as the interface factor. The cryo-deformations of air-entrained mortars with different spacing factors are evaluated through the poromechanical model. The results indicate that both thermal contraction and negative liquid pressure dominate the freezing shrinkage of materials, and the hydraulic pressure contributes most to the freezing expansion as spacing factor increasing.