Résumé
This study investigates the hygrothermal behaviour of six French limestones commonly used in construction. An extensive experimental program was carried out to characterize their mineralogical, microstructural, thermal, and hydric properties. The results reveal clear relationships between pore structure and hygrothermal performance. The capillary absorption coefficient increases with the volume fraction of pores larger than 2 μm, confirming the key role of pore size in liquid transport. Water vapour permeability decreases exponentially with tortuosity, highlighting the combined effect of pore connectivity and pore size distribution. Thermal conductivity decreases with increasing total porosity following a geometric-mean relationship, as described by the Woodside and Messmer model, while volumetric heat capacity shows a linear correlation with dry apparent density. Despite compositional similarities, significant variability in performance is observed among the stones. Under transient climatic conditions, coupled heat and moisture simulations – based on the Künzel model – closely match experimental temperature measurements and reasonably capture humidity variations. Minor discrepancies are attributed to sorption hysteresis, not accounted for in the modelling. The quantified links between hygrothermal properties and pore structure provide valuable insights for the selection and simulation of natural stone in energy-efficient envelope design.