Microstructural and hydro-mechanical behaviour of bentonite pellets and powder mixtures

Binary mixtures of high-density MX-80 bentonite pellets (80%) and bentonite powder (20%) at hygroscopic water content have been recently considered as an alternative engineered barrier system for the long-term disposal of radioactive wastes. These mixtures display a dry density of around 1.49 Mg/m3...

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Detalles Bibliográficos
Autores: Mesa Alcantara, Arisleidy, Romero Morales, Enrique Edgar|||0000-0002-4105-8941, Mokni, Nadia, Olivella Pastallé, Sebastià|||0000-0003-3976-4027
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/339970
Acceso en línea:https://hdl.handle.net/2117/339970
https://dx.doi.org/10.1051/e3sconf/202019504003
Access Level:acceso abierto
Palabra clave:Radioactive waste disposal in the ground
Bentonite deposits
Residus radioactius -- Emplaçament
Bentonita -- Propietats mecàniques
Àrees temàtiques de la UPC::Enginyeria civil::Geotècnia::Mecànica de sòls
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament dels residus
Descripción
Sumario:Binary mixtures of high-density MX-80 bentonite pellets (80%) and bentonite powder (20%) at hygroscopic water content have been recently considered as an alternative engineered barrier system for the long-term disposal of radioactive wastes. These mixtures display a dry density of around 1.49 Mg/m3 on pouring and present components with multi-modal pore size distributions that significantly evolve during the hydro-mechanical paths. To better understand the hydro-mechanical behaviour of this multiple porosity mixture, the contribution initially focuses on describing the initial state, as well as the main microstructural features determined by mercury intrusion porosimetry tests for the mix and each of the components (pellets and powder). Afterwards, hydro-mechanical results of both components and the mixture are presented. The hydraulic results focus on the water retention and water permeability, while the mechanical tests concentrate on the compressibility properties on loading.