Modelling the hydromechanical behaviour of expansive granular mixtures upon hydration

Bentonite pellet-powder mixtures are candidate sealing materials in radioactive waste disposal concepts. The mixture is installed in galleries in dry state as a granular material. The material is progressively hydrated by the pore water of the host rock and becomes homogeneous. Before homogenisation...

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Bibliographic Details
Published inE3S web of conferences Vol. 195; p. 2006
Main Authors Darde, Benjamin, Tang, Anh Minh, Pereira, Jean-Michel, Dangla, Patrick, Roux, Jean-Noël, Talandier, Jean, Vu, Minh Ngoc
Format Journal Article
LanguageEnglish
Published EDP Sciences 01.01.2020
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Summary:Bentonite pellet-powder mixtures are candidate sealing materials in radioactive waste disposal concepts. The mixture is installed in galleries in dry state as a granular material. The material is progressively hydrated by the pore water of the host rock and becomes homogeneous. Before homogenisation, the granular structure controls the material behaviour. In the present work, a modelling approach able to address particular features of pellet-powder mixtures is introduced. Two domains are considered: i ) granular, and ii ) homogeneous. The material behaviour before homogenisation is studied through Discrete Element Method (DEM) simulations. Constitutive laws for the granular state are proposed from DEM results. The behaviour of the homogenised material is described by a modified Barcelona Basic Model (BBM). Transition from granular to homogeneous states depends on suction and relative volume fractions of pellets and powder. Swelling pressure tests performed in the laboratory are satisfactorily simulated using this approach.
ISSN:2267-1242
2267-1242
DOI:10.1051/e3sconf/202019502006