Modelling of electro-osmosis in clayey materials including pH effects

A multiscale approach (periodic homogenization) is carried out to model clayey materials behaviour, and especially the coupled phenomena that govern electro-osmotic process. Clays are composed of a charged solid phase saturated by an aqueous electrolyte containing four ionic species Na+, Cl−, H+ and OH−. The novelty of this approach consists in the integration of chemical reactions in our description. Thus influence of ionic exchanges that occur at the platelet’s scale can be propagated at the macroscale. In particular, suction effects observed in electrokinetic soil processing can be explained by this approach.