Micromechanical analysis on deterioration due to freezing and thawing in porous brittle materials

A porous brittle material such as concrete or rock deteriorates when subjected to freezing and thawing. Based on a hypothesis that the cause of the deterioration is the fracture of micropores due to water freezing and moving in them, a micromechanical model is constructed for these microscopic processes and an analysis method of predicting the deterioration degree is developed. The validity of the deterioration analysis is examined by conducting numerical simulation for experiments which were carried out in various conditions. It is shown that the analysis can reproduce the measured data quantitatively. Since the temperature and local stress influence the deterioration process, an FEM is formulated for the deterioration analysis; this is coupled with the heat transfer and mechanical deformation analysis. As an example, the deterioration is analyzed for a rock cavern which stores LNG. The results appear in good agreement with the qualitative prediction of experts.