Effects of the freeze–thaw (F–T) cycle on the andesitic rocks (Sille-Konya/Turkey) used in construction building

• Physical and mechanical properties of andesite exposed to F–T cycles change.
• The most important factor in F–T process is the existence of water.
• New macro and micro fractures occur at andesites exposed to F–T cycles.
• The weathering of andesites depends on their dimensions and position.

Stones used in the construction of cultural and historical buildings are exposed to various direct or indirect atmospheric effects depending on climatic and seasonal conditions. Stones deteriorate partially or fully as a result of this exposure. Therefore, the historicity of these buildings cannot withstand long. The freeze–thaw (F–T) process is one of the prominent conditions of this kind. Water penetration into the building stone via capillarity promotes weathering. When the temperature falls below 0 °C, the water freezes in the pores and tiny cracks of the building stones, causing volume expansion and exerting pressure on the stones. This cycle occurs most in areas where the temperature fluctuates above and below freezing often and causes and induces undesired weathering within the building stones. The Konya city, having been an old settlement province from 9000 B.C., encompasses quite valuable ancient buildings. Andesitic rocks, which are called Sille Stone in the region, were used in most of these buildings.In this study, fresh andesitic rocks obtained from the stone quarry were tested in five F–T cycles in the laboratory. Textural changes that occurred in the deteriorated stones were examined by a polarizing microscope. Changes in porosity (n), uniaxial compressive strength (σu), point load strength (IS(50)), Brazilian tensile strength (σt), Böhme abrasion loss (BA), and ultrasonic velocity were statistically evaluated, and the effects of the number of F–T cycles on basic physical and mechanical properties of the stone were determined. In addition, weathering effects in the historical buildings constructed from the Sille andesite were investigated.