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Communication dans un congrès

Optimization of pore network characterization of compacted clay materials by TEM and FIB/SEM imaging

Abstract : The transport properties of clay-rocks are controlled by their complex pore network and the reactive and negatively charged clay mineral surfaces. The Pore Size Distribution (PSD) and the geometrical features of the pore network constitute key parameters governing the migration of solvate elements through the clay formations. Upon the last few years, some works have contributed to improve the knowledge of some clay-rich rock pore networks by using innovative microscopic imaging techniques (FIB-nt, BIB, X-ray…). Even if these techniques allow imaging the mesostructure scale organization of clay-rocks and clay materials, these studies have however highlighted several limitations to fully represent the spatial distribution of pores in terms of PSD, geometry and connectivity. In the present work, we demonstrate that a multi-scale characterization of pore network of clay materials based on FIB-nt and TEM techniques is feasible and could be robustly achieved for providing some useful input data in order to assess a future modeling task. The studied material was a compacted clay materials composed of illite, a non-swelling mineral. Illite was chosen in order to represent an analog system mimicking the clay matrix of the clay-rocks. This compacted clay plug allows working on homogeneous system with a controlled porosity, facilitating the comparison between different methods. All the techniques used in the present work whether bulk or microscopic methods show that all results converge to a similar and entire PSD (figure 1). The main improvement of this work was to demonstrate how the usual resolution limitations and the data handling of the FIB-nt techniques could be improved in order to recognize a fully connected pore network.
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Communication dans un congrès
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https://hal-brgm.archives-ouvertes.fr/hal-01120597
Contributeur : Stéphane Gaboreau <>
Soumis le : jeudi 26 février 2015 - 10:12:43
Dernière modification le : mercredi 16 janvier 2019 - 14:05:08

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  • HAL Id : hal-01120597, version 1

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Stéphane Gaboreau, Jean-Charles Robinet, Dimitri Pret. Optimization of pore network characterization of compacted clay materials by TEM and FIB/SEM imaging. Clays in Natural and Engineered Barriers for Radioactive Waste Confinement, Mar 2015, Bruxelles, Belgium. ⟨hal-01120597⟩

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