Computational Simulation of Salt Transport and Crystallization in Surface Layers of Building Envelopes

A computational model of heat, moisture and salt transport in multi-layered systems of porous materials including salt crystallization is presented. A practical application of the model is illustrated for two different types of wall provided with interior and exterior plasters which are exposed to the climatic conditions characteristic for Central Europe. Temperature, water content, salt concentration and crystallized-salt amount fields are calculated for the time period of five years. Computational results show that water and salt transport parameters of both the load bearing structures and plasters play a very important role in the salt crystallization in surface layers. Lower transport parameters of materials of surface layers and higher transport parameters of materials of load bearing structures are found preferable.