Estimation of Solute Concentrations in Micro-pore and Macro-pore Solutions of Compacted Bentonite–Sand Mixtures

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• 作者：K. Ravi ; Sudhakar M. Rao
• 关键词：Bentonite ; Cation concentrations ; Micro ; structure
• 刊名：Geotechnical and Geological Engineering
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：35
• 期：1
• 页码：517-525
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Geotechnical Engineering & Applied Earth Sciences; Hydrogeology; Terrestrial Pollution; Waste Management/Waste Technology; Civil Engineering;
• 出版者：Springer International Publishing
• ISSN：1573-1529
• 卷排序：35

文摘

Densely compacted bentonite has been identified as a potential buffer in deep geological repositories as the expansive clay satisfies the hydro-mechanical and physico-chemical functions of the buffer material. A key feature in understanding the hydro-mechanical behaviour of compacted bentonite upon exposure to chemical concentration gradients is to estimate the solute concentrations in micro-pore and macro-pore solutions. This study describes a method based on measurements of total surface area, external surface area, c-axis (2d) spacings and volumetric calculations to determine the solute concentrations in micro-pore and macro-pore solutions of compacted bentonite-enhanced sand (BES) specimens. Results of the study with Barmer bentonite-based BES specimens illustrate that cation concentrations in micro-pore and macro-pore solutions are sensitive to variations in dry density. Further, the exchangeable cation concentrations in the micro-pore solution exceed the soluble salt-cation concentrations in the macro-pore solution of Barmer bentonite.