Water Retention Properties of a Mine Chalk

The water retention properties of a chalk from an abandoned underground mine in Northern France were studied and related to changes in relative humidity (RH) in the mine in an attempt to better predict the long term stability of the mine. Chalk microstructure was investigated by scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP). It has been shown that some experimental techniques commonly employed for controlling and measuring suction in unsaturated soils can be easily used to determine the retention properties of chalk. The comparisons between the results obtained using these techniques allowed to have an insight into the effect of mineralogy and pore morphology on the retention properties of the chalk.