SALT CRYSTALLIZATION IN POROUS CONSTRUCTION MATERIALS .1. ESTIMATION OF CRYSTALLIZATION PRESSURE

The crystallization process of soluble salts inside the natural and ar tificial porous materials partially immersed in different saline solut ions has been studied. This procedure is used to simulate the conditio ns of exposure to salt weathering in which foundations and lower walls of building structures are within the zone of capillary rise of salin e ground water. Crystallization pressures that can develop in the samp les, which are a function of the pore size and salt-solution interfaci al tension, have been calculated and are compared with experimental va lues of the materials tensile strength, since both these parameters al low the prediction of porous materials behaviour against salt weatheri ng.