Thermomechanical model of hydration swelling in smectitic clays: II three-scale inter-phase mass transfer: homogenization and computational validation
✍ Scribed by Murad, Márcio A.
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 339 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0363-9061
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✦ Synopsis
In Part I a two-scale thermomechanical theory of expansive compacted clays composed of adsorbed water and clay platelets was derived using a mixture-theoretic approach and the Coleman and Noll method of exploitation of the entropy inequality. This approach led to a two-scale model which describes the interaction between thermal and hydration e!ects between the adsorbed water and clay minerals. The purpose of this paper is twofold. Firstly, partial results toward a three-scale model are derived by homogenizing the two-scale model for the clay particles (clusters of clay platelets and adsorbed water) with the bulk water (water next to the swelling particles). The three-scale model is of dual porosity type wherein the clay particles act as sources/sinks of water to the macroscale bulk phase #ow. One of the notable consequences of the homogenization procedure is the natural derivation of a generalized inter-phase mass transfer equation between adsorbed and bulk water. Further, variational principles and "nite element approximations based on the Galerkin method are proposed to discretize the two-scale model. Numerical simulations of a bentonitic clay used for engineered barrier of nuclear waste repository are performed and numerical results are presented showing the in#uence of physico-chemical e!ects on the performance of the clay bu!er.