A multi-scale study of the effect of zinc and lead on the hydromechanical behaviour and fabric of a montmorillonite

Abstract

The paper presents a study of some macroscopic properties of a plastic clay saturated with water and lead or zinc solutions at 1M concentration, in relation to its fabric. The study shows that the zinc- and lead-saturated samples present lower liquid limit, lower free swelling strain and swelling pressure, and higher permeability. X-ray diffraction analysis shows that the presence of lead results in an increase in the anisotropy of the sample. With zinc, the fabric isotropy increases, which can be attributed to higher clay–metal interactions. Mercury intrusion porosimetry shows that the saturation of the sample with lead and zinc reduces the inter-aggregate pore volume.