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

Fuyuan Gong, Evdon Sicat, Tamon Ueda and Dawei Zhang Journal of Advanced Concrete Technology, 11, 49-60, 2013 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.

The meso-scale model, which is the original model developed by the authors’ research group, was again extended in this study to simulate the mortar deformation under freeze thaw load. Although only theoretical basis has been given without showing precisely quantitative prediction with the test results, the proposed model exhibits the continuous advancement to cover one more aspect. (Prof. Somnuk Tangtermsirikul) The authors have proposed an analytical model based on heat and moisture transfer mechanism and ice formation process in mortar. The model has the potential for quantifying the degradation of mortar and concrete due to freeze-thaw action. (Prof. Folker H. Wittmann)