ABSTRACT
A macroscopic model for highly compacted expansive clays composed of a charged solid phase saturated by a binary monovalent aqueous electrolyte solution is derived based on a scale-up of the microstructure. The homogenization technique is applied to propagate information available in the pore-scale model to the macroscale. Macroscopic electrokinetic phenomena such as electro-osmotic flow driven by streaming potential gradients, electrophoretic motion of mobile charges and osmotically induced swelling are rigorously derived by homogenizing the microscopic electro-hydrodynamics coupled with the Poisson-Boltzmann problem governing the movement of the electrolyte solution and electric potential distribution. A notable consequence of the upscaling procedure proposed herein are the micromechanical representations for the electrokinetic coefficients and swelling pressure.
