Differentiated intra- and inter-aggregate water content models of mx-80 bentonite

• Differentiated models of intra and inter-aggregate water content are proposed.
• An MX-80 bentonite is analysed.
• Data from suction-water content retention curves are used.
• A macro–micro double porosity model is used as conceptual framework.
• An isotropic swelling test is modelled illustrating the advisability of the method.

The current research proposes a method for obtaining the intra-aggregate (microstructural) and inter-aggregate (macrostructural) water content of MX-80 bentonite using data from water retention curves. Data associated with high suction were used to define the microstructural water content model. By extrapolating this model to low suction, microstructural and macrostructural water contents were separated to obtain a macrostructural water content model. Micro- and macrostructural water content models have been used to simulate an isotropic swelling test, thus illustrating the advisability of using a double and differentiated macro/micro description of the water content to characterise the hydro-mechanical behaviour of MX-80 bentonite.