Thermo-hydro-mechanical behaviour of tuffeau stone masonry

This paper deals with thermo-hydromechanical behaviour of a stone masonry wall assembled with mortar. Macroscopic modelling is proposed that allows an evaluation of the impact of everyday thermal and hydraulic variations on the generation of variations in effective stress. The thermo-hydromechanic parameters of the unsaturated stone have been estimated by experimental tests for tuffeau, such as that found in the Chambord monument. An inverse identification has been used for the optimisation of these parameters based on in- situ measurements, before using the model for long-term analysis. The results of this numerical study show that the contrast between the properties alone is not sufficient to generate a stress that is superior to the stone strength. Otherwise, the variations in thermal and hydraulic conditions on the surface of the stone could lead to a fatigue-like degradation of historic monuments.