Aspects of the Clay/Electrolyte/Water System with Special Reference to the Geotechnical Properties of Clays: Fid-Bau Portal

Aspects of the Clay/Electrolyte/Water System with Special Reference to the Geotechnical Properties of Clays

Stçepkowska, Ewa T.

Abstract The solid phase of the clay/electrolyte/water system is composed of platy clay particles (of variable thickness, δ, and variable specific surface, S) and of crystal phase (hygroscopic) water, wherefrom δ and S may be estimated. Diffuse layer water between parallel particles and other structural elements at the mutual distance 2d, Wd = d S ρw, and macropore water form the liquid phase. Particles are arranged in domains and and clusters, these in aggregates in an “aggregate lattice” with vacancies (macropores) and further superstructures are formed. Contact bonds may develop and long-range forces exist between structural elements, which govern the clay geotechnical behaviour. Cohesion is usually due to van der Waals attraction, friction component–to contact bonds and particle delamination, swelling and suction–to diffuse layer repulsion. Most phenomena may be explained in terms of the equilibrium condition between attraction and repulsion. Heat dissipation must be considered in mechanical processes. The angle of effective stress env envelope is correlated with particle thickness, thus therefrom clay strength may be estimated.