Microstructural changes in red clay on drying-wetting paths

Abstract

<p indent=0mm>Taking Guilin red clay as the research object, scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) tests were conducted to study the microstructural evolution laws of compacted and reconstituted soils with different initial void ratios on drying-wetting paths. The SEM results show that the microstructure of the saturated compacted soils mainly comprises aggregates, interaggregate pores, and intraaggregate pores (interparticle pores). The microstructure of the saturated reconstituted soils mainly comprises layered clay particles and relatively uniform interparticle pores. The MIP results show that the pore size distribution curves of the compacted and reconstituted soils exhibit a bimodal and a unimodal distribution, respectively. On the drying-wetting paths, the changes in the interaggregate pores are the main factor for the compacted soils, while the changes in the interparticle pores are the only factor for the reconstituted soils. Compared with the compacted soils, the initial void ratio has less effect on the pore change of the reconstituted soils.