Meso-scale Mechanical Model for Mortar Deformation under Freeze Thaw Cycles

Frost damage mechanism under freezing and thawing cycles is an important issue for service life evaluation of concrete structures in cold regions. In order to simulate the frost damage mechanism, this paper presents a simulation method in meso-scale for coupled mechanical and transfer analysis in which Rigid Body Spring Model (RBSM) is applied. This method can simulate the coupled heat and moisture transfer in mortar, and also the ice formation process based on thermodynamic equilibrium. In addition, a degradation constitutive model is proposed to describe the deformation behavior under several Freezing and Thawing Cycles (FTCs). To evaluate the effectiveness of this method, the simulation results are compared with experimental data of the strain behavior under FTCs and found in satisfactory agreement with the experimental data.