Salts in the deterioration of porous materials: An overview

The present overview on salt induced deterioration of inorganic porous mate rials focuses on those topics considered the most relevant for understandin g this phenomenon. these are movement of both water/moisture and salts with in the pore system; influence of the presence of salts in moisture absorpti on; effect of the simultaneous presence of more than one salt; salt distrib ution in masonry; deterioration mechanisms; and weathering patterns. Of the latter, the most ubiquitous are powdering and scaling, and they have been found to occur on most stone types. However, the mechanism that induces the same outward appearance on different stones can vary significantly dependi ng on the synergism that develops among porous material, salt, and moisture .