Stones are one of the most widely used building materials that have unique properties an‎d are not interchangeable with any other materials, even Engineered stones. All rocks are affected by weathering an‎d lose some of their original properties. One of these weathering factors is temperature, which affects the properties of rock in various ways. Given that rocks are composed of different minerals an‎d the size of their constituent particles is different, their responses to the weathering factor of temperature are also different. Therefore, the science of choosing the right stones, especially for decorative an‎d facade uses, requires knowing their sensitivity to different temperatures. In this study, the surface properties of 7 granite rocks an‎d 5 carbonate rocks with polished surfaces were studied to study the effect of low temperatures, an‎d few studies have been conducted in this field. The stone samples were subjected to 25 cycles of aging an‎d thermal shock, an‎d then their roughness was measured an‎d their gloss was measured at an angle of 60 degrees an‎d studied. Thermal aging tests involve keeping the samples in an oven at 105°C for 18 hours an‎d then at room temperature of 20°C for 6 hours. Thermal shock testing is similar to thermal aging testing, except that instead of staying at room temperature, the samples are placed in water at a constant room temperature for 6 hours. These treatments have been used in the past by other researchers, an‎d on hot summer days, especially in hot regions an‎d some parts of Iran, this temperature is almost achieved on surfaces exposed to sunlight. Finally, they were analyzed in statistical software to compare the relationships between changes in roughness an‎d gloss with some of the primary properties of the stone. It was found that during this study, roughness increased by an average of 25.5% in thermal aging treatment an‎d 85.4% in thermal shock treatment, an‎d gloss decreased by an average of 2.4% in thermal aging treatment an‎d 8.4% in thermal shock treatment, indicating damage to the surface.

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لهراسب فرامرزي

راحب باقرپور , عليرضا باغبانان