Investigating the microstructure changes for silty soil during drying

Abstract

This note investigates the drying-induced microstructure evolution of reconstituted Jossigny silt through mercury intrusion porosimetry tests. It was observed that when the water content is higher than the shrinkage limit, the pore size distribution (PSD) curve shifts to smaller diameter, but with further drying, the PSD curve starts to shift to larger diameter. This suggests the possible presence of drying-induced internal micro-fissures, which cannot be visualised by the naked eye, and which have developed in the residual shrinkage stage. These fissures are believed to have occurred in the clay fractions and in the interface between silt grain and clay particles.