Genesis of Quick Clay: A Nanometric Experimental Investigation on Geological Environment

Abstract Quick clays are fine-grained soils with high sensitivity that transform into a liquid when remoulded. The deposition history directly impacts the composition and microstructure of natural clays. This study examines the morphology at the nanoscale of two different sensitive Swedish clays (Lödöse and Kärra clay) to establish a connection between the microscopic features and the macroscopic mechanical behaviour observed at their intact and remoulded state. Using in-line holotomography, the nano-scale imaging instrument at the ID16B beamline of ESRF is employed to capture nano-level features in the natural clay specimens. The results illustrate that the size of the silt grains and the macroporosity are smaller for Lödöse clay than for Kärra clay. This might indicate the higher sensitivity of Lödöse clay. Although the macroporosity of Kärra clay reduces by 32% after remoulding, the difference in macropores recorded after remoulding Lödöse clay is negligible.