Technical aspects of mercury intrusion porosimetry for clays

Abstract

This paper presents a comprehensive and consistent investigation on three technical aspects associated with mercury intrusion porosimetry (MIP) applied to clayey soils: the effect of intrusion rate, the effect of the freeze-drying method and the influence of sample size. Although a limited number of publications provide recommendations about the MIP technique, the aforementioned effects were largely left unaddressed. This study was performed on four different soils, having different microstructures. In order to obtain a quasi-static condition at the applied pressure, the smallest intrusion rate was suggested to be used in the MIP tests. It was found that the freezing technique does modify the pore size distribution, due to expansion of water on freezing. The more water in the soil specimen, the more pronounced the effect. The specimen size also matters for similar reasons. The outcome of this study provides a technical basis for MIP on clayey soils.