Chapter 9 - Mechanical Properties of Clays and Clay Minerals

Abstract

Abstract Consistency and strength of cohesive and non-cohesive soils are very different. In general, higher clay contents in a soil cause higher plasticity, greater shrinkage and swell potential, higher compressibility and lower shear strength. Most mechanical properties of clays depend on the type and content of clay minerals, the interactions between the clay mineral particles and pore water, as well as on the sedimentary and consolidation history. Damages on clay-containing buildings can occur at a long time after construction because of volume changes due to swelling or shrinkage processes or very slow but extensive settlement. Another important characteristic of clays is the very low hydraulic conductivity as well as gas permeability. The soil mechanical behaviour of some problematic clays like expansive or swelling soils, quick clays and black shales is described in detail.