1. Modeling the homogenization of a heterogeneous granular bentonite mixture
- Author
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Navarro Gámir, Vicente, Torres Serra, Joel, Romero Morales, Enrique Edgar, Asensio Sánchez, Laura, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, and Universitat Politècnica de Catalunya. GGMM - Grup de Geotècnia i Mecànica de Materials
- Subjects
Macroporosity ,Macroscopic approach ,Clay aggregate ,Microporosity ,Bentonite ,Grain ,Megaporosity ,Bentonita ,Enginyeria civil::Geotècnia::Mecànica de sòls [Àrees temàtiques de la UPC] ,Granular bentonite mixtures - Abstract
A hydro-mechanical model of a heterogeneous granular bentonite mixture is presented based on discretization into a finite number of “bentonite units”, systems in which “megapores” are considered between bentonite grains, which, in turn, contain micro- and macropores. A macroscopic approach is used, where pore levels are associated with superposed homogeneous continua. Mixture heterogeneity is incorporated into the model considering the potentially very different percentage of megapores and grains in adjacent bentonite unit pairs. Mechanical contact is therefore affected, so a strategy is proposed based on porosity values, controlling deformability by the most deformable of the two units in contact. The constitutive formulation was implemented on a numerical solver to simulate a confined hydration test on a granular bentonite mixture with a notable initial local heterogeneity. The reproduced experimental evolution of the swelling pressure, relative humidity distribution, and water inflow was satisfactory. Porosity variation data were synthesized through histograms, describing not only the variation of the maximum and minimum porosity values but also the evolution of the porosity distribution in the mixture. This provides a quantitative description of the homogenization process, allowing an assessment of its scope and technological interest. This work is part of the project PID2020-118291RB-I00 funded by MCIN/AEI/ 10.13039/501100011033. This work was also supported by a ‘Margarita Salas’ grant from Ministerio de Universidades – Gobierno de España, awarded to Joel Torres-Serra.
- Published
- 2023