A simple three dimensional model for salt diffusion and crystallization in historical masonry

The conservation of historical masonry structures is a problem of great importance in Europe and especially in Italy where the cultural heritage has unique dimensions. The causes of deterioration can be subdivided in two main groups: physico-chemical and mechanical ones. The mechanical behavior of the masonry has been extensively studied in literature, while less attention has been devoted to model the processes of environmental degradation of masonry. The aim of this work is to propose a simple model able to describe the diffusion and the crystallization of salt in masonry structures. The primary variables of the model are: the pore humidity, the dissolved salt concentration and the concentration of crystallized salt. Some numerical tests are shown to demonstrate the effectiveness of the model.