The role of different salt solutions and their concentration ratios in salt crystallization test on the durability of the Döğer tuff (Afyonkarahisar, Turkey) used as building stones of cultural heritages

Volcanic tuff is widely used in Anatolian architecture and represents building stones of cultural heritage. The present study included a relevant assessment of the effect of four salt types and their four different concentrations on the durability of the Döğer tuff used as building stones of cultural heritages, which is subjected to salt crystallization tests. For this purpose, an investigation was conducted on their chemical, mineralogical-petrographical (polarized microscopy, XRD, SEM analyses, pore size distribution), and physical and mechanical properties as well as their deterioration behavior in the salt crystallization test by different salt solutions (and their different concentrations). In salt crystallization tests, sodium sulfate (Na₂SO₄·10H₂O), magnesium sulfate (MgSO₄·7H₂O), sodium chloride (NaCl), and potassium chloride (KCI) solutions were used, and 2, 5, 10, and 14% concentration ratios were used for each salt solution. In this work, it was observed some physical and mechanical values decreased along with weight loss in samples. The ultrasound pulse velocity (UPV) and uniaxial compression strength (UCS) values of the Döğer tuff samples in all the salt solutions and concentrations decreased after the 15 test cycles. The tested Döğer tuff samples completely broke down in the 10% and 14% concentrations in the sodium sulfate, magnesium sulfate, and potassium chloride solutions.