Investigation of the weathering properties of rocks used in historical structures in the Konya region

In this study, it is aimed to investigate the weathering properties of trachyte, tuff, travertine and marble used in historical structures located in the Konya region. For this purpose, the weathering occurred in different rock materials, which were used in construction of historical monuments located in Konya center such as Hacı Veyis Mosque, Mevlâna Museum and Lodge, Aziziye Mosque, Kapı Mosque, Alâeddin Mosque, İnce Minareli Madrasa and the Sahip Ata Complex, was investigated. The locations of rock units that are thought to be used in the construction of these historical monuments were identified by field studies. Core and hand samples were extracted from these locations to be used in laboratory studies. For the determination of the physical, mineralogical and mechanical properties of the collected samples, porosity, water absorption by weight, unit weight, X-ray diffraction analysis (XRD), petrographic analysis as well as uniaxial compressive strength tests were carried out. In addition, wetting-drying and freezing-thawing experiments were carried out to determine the effect of physical weathering processes on the disintegration behavior of these rock units. Beside these experimental studies, in order to investigate the weathering behavior of selected rocks used in the construction of the historical monuments at natural field condition, core and hand samples extracted from these rocks were subjected to weathering processes in an open garden in Konya center during one year, and the mass losses were recorded. Considering the weathering depths measured in historical structures, it was determined that the weathering rates of trachyte, tuff, travertine and marbles are 0.01-0.10 mm/year, 0.02-0.08 mm/year, 0.01-0.30 mm/year, and 0.009-0.03 mm/year respectively. Based on the test results of freezing-thawing and wetting-drying, it was found that the mass loss percentages of trachyte, tuff, travertine and marbles are 0.58-1.52, 16.11-17.68, 0.11-0.34, and 0.58-2.67 respectively. In addition, the mass loss percentages of trachyte, tuff, travertine and marble samples kept in the natural environment were determined as 0.794-1.008, 17.02-17.268, 0.32-0.374 and 0.648-0.852 respectively. Considering the results obtained, it was found that the weathering behaviors of the rocks determined at the field conditions and the laboratory are similar. In comparison with tuff, it was determined that the mass loss values of the rock materials such as trachyte, travertine and marble are quite low (between 1-3%). Taking into account the durability of the selected rocks against weathering processes, Sille tuffs are thought not to be used in restoration of historical monuments and engineering projects such as construction of new structures. Keywords: Weathering, weathering behavior, Marble, Historical Monuments, Trachyte, Travertine, Tuff.