ASSESSMENT OF SALT CRYSTALLIZATION THROUGH NUMERICAL MODELLING

Salt crystallization is one of the major factors of degradation of porous materials such as masonry. This paper presents a coupled multiphase model for hygrothermal analysis of masonry structures and the effective prediction of stress induced by salt crystallization. The independent variables chosen to describe all the process are: the pore humidity, the concentration of dissolved salt and the temperature. The governing equations of the model are: the moisture balance equation, expressed in function of the humidity, the conservation equation for the total stored energy, the balance equation for the dissolved salt and a kinetic expression for the salt crystallization law. The model is used to simulate the results of an extensive experimental campaign carried out on a masonry wall exposed to weather conditions for four months.