Modelling of compacted bentonite swelling accounting for salinity effects

This paper presents a formulation to incorporate the influence of water salinity on the swelling behaviour of a MX-80 bentonite into previously developed hydro-mechanical models that can reproduce swelling under dilute conditions. The effects of salinity on macro- and microstructural water chemical...

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Detalles Bibliográficos
Autores: Navarro Gamir, Vicente, Yustres Real, Ángel, Asensio Sánchez, Laura, Morena Borja, Gema de la, González Arteaga, Jesús, Laurila, Teemu, Pintado, Xavier
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universidad de Castilla-La Mancha
Repositorio:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/24819
Acceso en línea:https://doi.org/10.1016/j.enggeo.2017.04.016
https://hdl.handle.net/10578/24819
Access Level:acceso abierto
Palabra clave:Bentonite swelling
Salinity effects
Electrochemical potential
Destructuration
Modelling
Descripción
Sumario:This paper presents a formulation to incorporate the influence of water salinity on the swelling behaviour of a MX-80 bentonite into previously developed hydro-mechanical models that can reproduce swelling under dilute conditions. The effects of salinity on macro- and microstructural water chemical potentials were introduced. In addition, a description of solute transport was included to characterise the evolution of the system’s salinity. A simplified geochemical model was adopted to idealise the geochemical complexity of bentonite. In addition, the modelling of the destructuration process that occurs during swelling was modified to account for the effect of salinity. The formulation was implemented in a multiphysics partial differential equation finite element solver, and the numerical model was used to simulate several vertical free swelling tests with feed water of different salt contents (deionised, 10, 35 and 70 g/L). The results demonstrate that even though the model can be developed further, it represents a significant improvement over models that do not account for the effects of salinity.