Effect of supercooling on the instantaneous freezing dilation of cement-based porous materials

Abstract

This study seeks to assess the instantaneous deformation of saturated cement-based porous materials induced by supercooling of pore fluid. Thermodynamic equilibria account for the physical behaviors of the confined crystallization of ice for partially frozen porous systems. Pore pressure is built up when ice forms in pores, and this can be intimately related to the pore structure of the porous materials. To overcome the metastability of supercooled water that surpasses a normal poromechanical description, a special program for cooling has been designed. The hydraulic pressure resulting from rapid ice formation and the thermal shock caused by heat release account for an observed dilation peak. The lower the supercooled temperature, the larger the dilation peak becomes. Rapid pore pressure relaxation accounts for significant contraction following the dilation peak. The pore structure also has a significant impact on the freezing deformation of the cement-based porous materials. Results obtained in these examples are comparable with previously published data, which confirms the importance of the detrimental effects of supercooling in porous materials.