Durability assessment of Central Anatolian (Kayseri- aksaray) tuffs to be used as building stone

Ertaş Deniz, Burcu
Tuffs have been extensively used as a source of building stone for outdoor and indoor decorations because of their light color, light weight, good heat and sound insulation characteristics. However, there are no successful criteria in the world to be applicable for durability assessment of the tuffs. The purpose of this study is to assess the longterm durability of the tuffs taken from different local quarries and used as building materials in the ancient monuments mainly located in Kayseri and Aksaray provinces of Central Anatolia. In order to accomplish this task, field studies were undertaken to find the original quarries from which the tuffs were taken in selected ancient monuments. From nine quarries, 13 fresh tuff samples were taken and analyzed in the laboratory for their chemical, petrographical and physico-mechanical properties. Durabilities of the tuffs were assessed using available methods such as average pore diameter, saturation coefficient, wet-to-dry strength ratio and static rock durability index. Furthermore, new durability assessment methods were suggested using two index parameter correlation graphs and statistical methods such as factor analysis, multiple regression analysis (MRA) and analytical hierarchical process (AHP). The outputs of these new durability assessment methods were compared with the existing durability assessment methods and field performances of the tuffs in the ancient monuments. Based on these comparisons, it is found that the use of two selected physico-mechanical properties correlation graphs, MRA and AHP models can successfully predict the durability of tuffs to be used as building stone.