To control heat and mass transfer during freezing, it is essential to understand the phase change behavior of ice crystals. However, limited research has been performed on the coupling effects involved in the kinetics of ice crystal nucleation and growth with fluid flow and heat transfer in porous media. In this paper, the conditions of nucleation and crystal growth, which must be met during the ice crystallization process, were studied. In the process of water freezing, we thought water activity is the inducing factor of the ice-water phase transformation. Based on the 'water-activity criterion', a macro kinetic model of ice crystal growth was established, which is useful to quantify the processes of nucleation and growth coupled with fluid flow and heat transfer. The driving force of moisture migration is the chemical potential gradient under different temperatures based on thermodynamics, which is different from the conventional form obtained from Darcy's law. In addition, a mathematical model coupling the heat-fluid transport in a fully saturated soil with phase change was proposed. Because the problem is significantly nonlinear, a numerical method for its solution was applied, and the temperature, moisture and frost heave of a soil column during the freezing process were calculated. Validation of the model is illustrated by comparisons between the simulation and experimental results. From this study, it is found that temperature has a great influence on the distribution of the total water content during ice crystallization and moisture migration, and the relationship between water velocity and temperature can be used to explain the distribution of the water content. The predicted values are consistent with the experimental data and verify the accuracy of the crystallization kinetics approach that couples heat and mass transfer in porous media. (C) 2015 Elsevier Ltd. All rights reserved.