Soluble Salts Transport in Building Materials

The most widely used materials in building construction are porous materials and the combined effect of rising dampness with soluble salts is one major problem. This phenomenon is caused by the migration of the salt ions dissolved in water into the porous network of the construction materials in the building walls, which causes fractures in the materials after several cycles of crystallization/dissolution. This work presents an extensive experimental campaign with different cycles of water absorption (capillarity absorption tests) and drying (drying tests). The samples of building material used are red brick, and the samples were, previously, submitted to capillarity absorption tests with two different saturated solutions (sodium sulphate and potassium chloride). The results showed that the two salts studied influence the porous materials and their capillary coefficient in clearly different ways and the samples immersed in sodium chloride present higher drying rates than those immersed in a saturated sodium sulphate solution.