A semi-empirical model for phase composition of water in clay–water systems

A semi-empirical model describing the variation of the unfrozen water content wu in frozen soil–water systems as a function of temperature has been proposed based on the results of 141 DSC experiments on 6 monomineral soils. Taking into account the postulate of the simplicity of the model, the three-temperature-zone representation of the freezing process is assumed as an alternative to the five-zone image resulting from the DSC experiment. The characteristic temperatures are the freezing (or melting) point Tf and the temperature Tm, below which the unadsorbed water is all frozen. The main equation of the model describes the variation of the unfrozen water content in the mushy zone between Tf and the temperature Tm. In addition, the empirical equations for the freezing point and the unfreezable water are given. The model was validated with foreign empirical data. The results show a very good agreement between the simulated and the measured unfrozen water contents.