Physical and Chemical Properties of Bentonite Modified by Electrochemical Treatment
Publication: International Journal of Geomechanics
Volume 24, Issue 10
Abstract
Expansive soils are characterized by significant swelling and shrinkage due to changes in water content, which could threaten the safety of buildings. In this study, an electrochemical treatment method was used to modify bentonite, with subsequent analysis focused on evaluating the alterations in its physical and chemical properties. The electrical resistance between the soil and the electrodes was significantly reduced by injecting a CaCl2 solution, leading to a substantial decrease in voltage loss at the anode. The thickness of the electrical double layer decreased as the Na+ cations adsorbed by smectite particles were exchanged by Ca2+ ions, which significantly decreased the water adsorption and free swelling ratio. The electrochemical treatment method removed more pore water from soil samples than the electroosmotic consolidation method. Furthermore, the results indicated that the injection of a CaCl2 solution could be effective in restraining the swelling potential of bentonite. The most suitable concentration for CaCl2 solution to modify bentonite by electrochemical treatment method might be 1 mol/L, and the injection volume could be 125 mL/L of soil. The results indicated that the electrochemical treatment method could be a promising in situ technique for modifying expansive soil.
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Data Availability Statement
All data, models, and codes generated or used during the study appear in the published article. The optical images for electrical current, electrical potential distribution, electroosmosis conductivity, and other parameters used for validation, possible discussions, comparisons, and other procedures used for interpretations are available from the corresponding author upon reasonable request.
Acknowledgments
This work was supported by the National Natural Science Foundation of China (Project No. 51979144), the State key Laboratory of Hydroscience and Engineering, the Tsinghua University (SKLHSE-2022-D-02), and the Fundamental Research Funds for the Central Universities (Project No. 2022MS050).
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Published In
International Journal of Geomechanics
Volume 24 • Issue 10 • October 2024
Copyright
© 2024 American Society of Civil Engineers.
History
Received: Jul 14, 2023
Accepted: Apr 29, 2024
Published online: Aug 8, 2024
Published in print: Oct 1, 2024
Discussion open until: Jan 8, 2025
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