Materials analyses guiding for repairs in conservation: An Historical Bath Structure “Yeni Hamam” in Sivrihisar, Turkey

The Ottoman baths which have survived for hundreds of years are the historical structures still keeping their authentic architectural and technological properties. The study deals with the discovery of the knowledge on materials technology that contributes to the long-term durability of those structures. The authentic materials of an 18 th century Ottoman bath structure, Yeni Hamam (Sivrihisar, Turkey) were examined in this regard, in order to define the specifications for compatible repair materials which is essential for conservation studies. The physical and physicomechamical properties of the original stone, brick, mortar and plaster samples as well as their compositional and raw materials characteristics were examined. The results have shown that a gradual decrease in ultrasonic pulse velocity and modulus of elasticity values was observed through the wall section starting from stone-brick masonry followed by levelling mortar and finishing plaster layers. These values were also in correlation with gradual decrease in density and gradual increase in porosity of the same materials layers, respectively. In terms of raw materials characteristics, all mortars and plasters were found to be highly-pozzolanic materials. A gradual decrease in pozzolanic activity characteristics was also observed within the layers of wall masonry, starting from stone masonry mortars continuing with levelling mortars/plasters and finishing plasters. In addition, the same materials layers present high breathing capabilities and that is also very crucial for a highly-moisture loaded hamam structure. The presence of such healthier relationships exhibits a proper combination of layers contributing to good adherence between their interfaces and a durable structure. The knowledge achieved on compositional properties of authentic materials has vital importance for the preparation of compatible repair materials. The presence salt problem and growth of macro and micro plants on roof, ceiling and floor signal the severe dampness problems in the structure. Further analyses supported with non-destructive testing methods are needed for maintenance studies