Coupled thermal–hygric characterisation of elastic behaviour for soft and porous limestone

• Soft limestone was exposed to −8 °C to 40 °C and 0–100% relative humidity.
• The measurements include strain, elastic modulus and Poisson’s ratio.
• The DOE methodology was successfully applied to obtain mathematical relationships.
• Determined elastic properties were compared with elastic properties at dry state.
• Dry state elastic properties are inaccurate to simulate field conditions.

The experimental work presented in this study was focused on examining the effect of the variation of two parameters: temperature and water saturation, on the elastic modulus, Poisson’s ratio, and dilation properties of a limestone used widely in French construction called tuffeau. Experimental results were treated using a design of experiment to assess the coupling effects of the studied parameters, and to create mathematical models used to estimate the measured elastic properties in the range of −8 °C to 40 °C for temperature and 0–100% for water saturation. The elastic properties, generally characterised in the dry state or without real coupling with water saturation, proved to be inaccurate for most environmental conditions, suggesting that the proposed models represent an essential contribution to any further research involving the simulation of outdoor conditions in soft limestone construction.