Читать книгу Monument Future - Siegfried Siegesmund - Страница 339

This study was carried out in two main stages: field studies and laboratory research. These field studies consist of site observation and sampling. During the site observation, special emphasis was given to the forms of stone weathering on the monuments located in Mardin. More than 20 monuments located in the study area were visited and their major forms of deterioration were recorded. For the sampling, limestone blocks were extracted from a quarry, located in Midyat, a district of Mardin. The stone blocks extracted from the quarry were then cut into 5 centimeters cubic samples. For the laboratory studies, a total of 30 cubic samples with 5-centimeter edge lengths were prepared. The samples were used to determine such physico-mechanical properties of the stone material as effective porosity, unit weight, water absorption, uniaxial compressive strength (UCS), thermal conductivity, volumetric heat capacity and saturation coefficient.

Figure 1: City of Mardin: (up) a view of historical city; (down) a sketch of Mardin (After Gabriel, 2014).

The laboratory tests were performed in the rock mechanics and natural stone laboratories of the Mining Engineering Department at Dicle University, in accordance with the standards and suggestions (ISRM 1981). Thermal properties of the limestone samples were examined on specimens having edge lengths of 7 centimeters. Thermal measurements 229were conducted using ISOMET 2104 device (supplied by Applied Precision) by following the procedure described in ASTM (2014). The measurements of thermal properties were based on the analysis of the thermal response of the questioned samples to the impulses of heat flow. Measurements were conducted on all faces of the cubic samples, and the arithmetic means of the measurements were considered as the final values of thermal conductivity and volumetric heat capacity.