Effect of multi-cycle freeze-thaw tests on the physico-mechanical and thermal properties of some highly porous natural stones

The durability of natural stone on a given project is generally quantified by evaluating its degradation ability caused by a multitude of factors. Frost action has significant effects on the fracturing and granular disintegration of the stone due to the occurrence of minor and major breakages, especially in the presence of water. It refers to more porous structure and so decrease in the strength and thermal conductivity of the mineral fabric. The aim of this study is to quantify the weathering damage of some porous natural stones caused by laboratory-based freezing-thawing cycles by means of the changes in some physico-mechanical (apparent porosity, P-wave velocity, colourimetric values, water vapour transmission rate and point load strength) and thermal (thermal conductivity) properties. For this purpose, an experimental physical weathering simulation was carried out on two carbonate and two magmatic, commercially available porous natural stone types as travertine, limestone (biocalcarenite), trachyandesite and tuff stone (ignimbrite), respectively. Laboratory studies reveal considerable variations for the trachyandesite and tuff stone with respect to changes in some intrinsic properties. The results clearly demonstrate a quite different resistance of these stones to freezing and thawing damage, and this was found to be strongly correlated with their thermal conductivity values.