Swelling pressure in compacted bentonite: Laboratory tests and modelling

The aim of this work is to extend an existent double structure model for expansive clays (Sanchez et al., 2005) to include the thermal effects in the analysis. Experimental results obtained in the context of the NF-PRO project have been used to extend the constitutive law. A fundamental characteristic of the double structure framework is the explicit distinction of two actual structural levels existent within the material: the macrostructural level, which accounts for the larger scale structure of the material and the microstructural level, associated with the active clay responsible for the swelling behaviour. In addition, the model considers the interaction between the two structural levels. In this paper the dependence of the swelling behaviour on temperature has been directly included in the constitutive law that describes the microstructural behaviour. This is the natural way to consider the thermal effects in expansive clays, as their swelling behaviour is controlled mainly by the clay minerals (microstructure).