Mesoscale Simulation of Deformation for Mortar and Concrete under Cyclic Freezing and Thawing Stress

Abstract

As one kind of porous medium, even without external loading, concrete material is still possible to be damaged by the internal pore pressures, such as hydraulic, crystallization and cryosuction pressures during freezing and thawing cycles (FTC). In this paper, a mesoscale model using Rigid Body Spring Method (RBSM) is developed to simulate the defor-mation behaviors of concrete under FTC cycles. On one hand, the macroscopic material is divided into small rigid ele-ments of mesoscale; on the other hand, the microscale internal pore pressures are regarded as average values in mesoscale based on poromechanical theories. The constitutive relation is also developed to reflect deformation compatibility be-tween porous body and ice-water system. Finally, the internal cracking and residual deformation are simulated for mortar and concrete using RBSM, which are found in a good agreement with previous experimental data.