A chemo-mechanical constitutive model accounting for cation exchange in expansive clays Academic Article uri icon


  • The paper presents a chemo-mechanical model for expansive clays that takes into account the effects of cation content and cation exchange. These factors play a key role in the mechanical behaviour of very active clays, particularly with regard to volumetric behaviour. The model is based on an existing double-structure formulation that distinguishes specifically between microstructure and macrostructure. Chemical effects are defined at the microstructural level, the seat of the basic physico-chemical phenomena affecting highly swelling clays. The microstructural model accounts for changes in both osmotic suction and in cation content. Microstructural strains are considered to be reversible; material irreversibility arises from the interaction between the two structural levels. The formulation is developed for general unsaturated conditions; saturation is considered as a limiting case. The model is successfully applied to the reproduction of experimental behaviour observed in oedometer tests on saturated bentonite subjected to chemo-mechanical loadings, and in hydration tests of unsaturated bentonite performed using different solute concentrations.

published proceedings


altmetric score

  • 9

author list (cited authors)

  • Guimaraes, L., Gens, A., Sanchez, M., & Olivella, S.

citation count

  • 64

complete list of authors

  • Guimaraes, L Do N||Gens, A||Sanchez, M||Olivella, S

publication date

  • January 2013