The effect of thermal stresses on the mechanical behaviour of natural building stones

The physical and mechanical properties of natural stones used in buildings and monuments are affected by degradation processes due to weathering agents such as thermal actions. The effect of this degradation on rock results in increasing microcrack density and, consequently, in different strength and deformability features of the rock materials. In order to investigate the influence of different crack densities in calcitic stones several experimental and theoretical studies have been carried out. Both destructive and non destructive test procedures have been adopted to evaluate the capability of different experimental techniques to estimate the rock material integrity. On the basis of experimental data and subsequently of their mathematical simulations through the analytical models this paper proposes an experimental methodology which, by means of non destructive measurements, would give a theoretical prediction of the rock material deformability in relation to the crack density.