Investigation of discrepancy between tuff used as building stones in historical and modern buildings in western Turkey

Tuffs located around the town of Alaçatı, Turkey have been used in building construction for many years in the past. Recently, based on the efforts of the local government to develop a unique identity for the town, this practice is re-initiated. After about five years from construction, tuff used in newly constructed buildings started to show signs of deterioration. Even though tuff used in recent and older buildings in the town appeared to be the same to the naked eye, a similar deterioration has not been observed in the buildings constructed in the past (some are more than 100 years old). A previous research study has documented the suitability of tuff used in new constructions but the reasons for the discrepancy between the tuffs used in construction of the older and newer buildings has not been previously investigated. In this study the different field performances of tuffs used for historical and modern buildings were investigated against deterioration in the same environment based on the material properties and their durability. This comparison showed that the mineralogical composition and amount of clay contents of the tuffs were one of the major factors resulting in difference in deterioration and durability rates of the tuffs used in building construction within the region.