The changes in the structure of limestone as a result of calcium sulfate (Gypsum stone) formation caused by atmospheric polluters

Abstract

Limestone has been a frequently used building stone in many buildings and monuments throughout the history of civilization and it's still being used in today's buildings, especially the kind that's known as marble and it has a crucial importance among the natural building stones. Hovewer, when it is used as a building stone in the urban environments where the atmospheric polluters are dense, some negativeness could be faced due to the atmospheric polluters. Among these polluters, SO x (sulphur oxides), NO x (nitrogen oxides) and CO x (carbon oxides) found intensly in urban atmosphere turns into an aggressive structure and causes serious damages on the limestone by merging with various factors acting as catalyst. The most important of these damage formations is the formation of calcium sulfate (gypsum stone) crust. Calciumsulfate develops on the surface of the limestone with the chemical reaction of atmospheric polluters and reachs a certain thickness and forms a thick crust layer in time. And in the next stage it disolves, tears in pieces because of the mechanic inner tension and the atmospheric factors such as rain, wind and frost and forthcoming damages and decompositions that can occur take a different dimension