A new double-porosity macroscopic model of bentonite free swelling

A macroscopic model based on a double-porosity approach is proposed to simulate the swelling caused by subdivision of particles and aggregates that occurs when bentonites are hydrated under high water content low confinement. In model, it assumed although occupies this new porous structure can be considered mobile (associated with macrostructure), its contribution variations in energy system similar immobile microstructure. Assuming isothermal conditions, functional relationship between increase void ratio decrease internal was defined from Clausius-Duhem equation. From relationship, constitutive derived determine macrostructural as function microstructural effective stress. The applied both tests large (up 50) processes notable variation salinity (from deionized 1 M solution), satisfactory results were obtained all cases. This study proposes simple strategy incorporate into equations generally used solve hydro-chemical-mechanical boundary problems at engineering scale thus direct practical interest.