Swelling Behavior and Flow Rates of a Novel Hydrophilic Gasket Used in Composite Geomembrane Vertical Cutoff Walls and Infrastructures Exposed to Contaminated Groundwater
The swelling capacity of novel hydrophilic gaskets used in geomembrane cutoff walls and infrastructures is critical for decreasing the flow rates of contaminated groundwater. This study investigated the swelling behavior, relaxation characteristics, flow rates, and micro-morphology of a hydrophilic...
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MDPI AG
2022-12-01
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| Series: | Buildings |
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| Online Access: | https://www.mdpi.com/2075-5309/12/12/2207 |
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| author | Min Wang Xianlei Fu Zheyuan Jiang Chi Che Ningjun Jiang Yanjun Du |
| author_facet | Min Wang Xianlei Fu Zheyuan Jiang Chi Che Ningjun Jiang Yanjun Du |
| author_sort | Min Wang |
| collection | DOAJ |
| description | The swelling capacity of novel hydrophilic gaskets used in geomembrane cutoff walls and infrastructures is critical for decreasing the flow rates of contaminated groundwater. This study investigated the swelling behavior, relaxation characteristics, flow rates, and micro-morphology of a hydrophilic gasket with different testing liquids. The radial swelling tests were performed using a device modified from single-lever consolidation instrument. A flow rates model apparatus was manufactured and employed to measure the flow rates of the poor-sealing hydrophilic gasket. According to the test results, the swelling ratio of the hydrophilic gaskets soaked in the DIW were the highest, followed by the NaCl solution, the MSW landfill leachate, and the CaCl<sub>2</sub> solution. Relaxation phenomena appeared in all the specimens regardless of the testing liquids. The flow rates of the specimens penetrated with DIW, NaCl, and CaCl<sub>2</sub> decreased to a stable state, and then increased extremely slowly to stable values. Moreover, self-healing of the hydrophilic gasket was observed. The micro-morphology indicated that sodium polyacrylate (PAAS) with insufficient expansion could separate from the matrix under high multivalent ionic strength or loading pressure conditions. Therefore, it is critical to develop the modified hydrophilic gasket with resistance to contaminated groundwater for a better barrier performance for use in contaminated sites and infrastructures. |
| first_indexed | 2024-03-09T17:15:06Z |
| format | Article |
| id | doaj.art-43721d041d06416299c878e6a56254b6 |
| institution | Directory Open Access Journal |
| issn | 2075-5309 |
| language | English |
| last_indexed | 2024-03-09T17:15:06Z |
| publishDate | 2022-12-01 |
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| spelling | doaj.art-43721d041d06416299c878e6a56254b62023-11-24T13:43:38ZengMDPI AGBuildings2075-53092022-12-011212220710.3390/buildings12122207Swelling Behavior and Flow Rates of a Novel Hydrophilic Gasket Used in Composite Geomembrane Vertical Cutoff Walls and Infrastructures Exposed to Contaminated GroundwaterMin Wang0Xianlei Fu1Zheyuan Jiang2Chi Che3Ningjun Jiang4Yanjun Du5Jiangsu Key Laboratory of Urban Underground Engineering & Environmental Safety, Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, ChinaJiangsu Key Laboratory of Urban Underground Engineering & Environmental Safety, Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, ChinaJiangsu Key Laboratory of Urban Underground Engineering & Environmental Safety, Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, ChinaJiangsu Key Laboratory of Urban Underground Engineering & Environmental Safety, Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, ChinaJiangsu Key Laboratory of Urban Underground Engineering & Environmental Safety, Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, ChinaJiangsu Key Laboratory of Urban Underground Engineering & Environmental Safety, Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, ChinaThe swelling capacity of novel hydrophilic gaskets used in geomembrane cutoff walls and infrastructures is critical for decreasing the flow rates of contaminated groundwater. This study investigated the swelling behavior, relaxation characteristics, flow rates, and micro-morphology of a hydrophilic gasket with different testing liquids. The radial swelling tests were performed using a device modified from single-lever consolidation instrument. A flow rates model apparatus was manufactured and employed to measure the flow rates of the poor-sealing hydrophilic gasket. According to the test results, the swelling ratio of the hydrophilic gaskets soaked in the DIW were the highest, followed by the NaCl solution, the MSW landfill leachate, and the CaCl<sub>2</sub> solution. Relaxation phenomena appeared in all the specimens regardless of the testing liquids. The flow rates of the specimens penetrated with DIW, NaCl, and CaCl<sub>2</sub> decreased to a stable state, and then increased extremely slowly to stable values. Moreover, self-healing of the hydrophilic gasket was observed. The micro-morphology indicated that sodium polyacrylate (PAAS) with insufficient expansion could separate from the matrix under high multivalent ionic strength or loading pressure conditions. Therefore, it is critical to develop the modified hydrophilic gasket with resistance to contaminated groundwater for a better barrier performance for use in contaminated sites and infrastructures.https://www.mdpi.com/2075-5309/12/12/2207hydrophilic gasketswelling ratiomodel apparatusflow ratesrelaxationsodium polyacrylate |
| spellingShingle | Min Wang Xianlei Fu Zheyuan Jiang Chi Che Ningjun Jiang Yanjun Du Swelling Behavior and Flow Rates of a Novel Hydrophilic Gasket Used in Composite Geomembrane Vertical Cutoff Walls and Infrastructures Exposed to Contaminated Groundwater Buildings hydrophilic gasket swelling ratio model apparatus flow rates relaxation sodium polyacrylate |
| title | Swelling Behavior and Flow Rates of a Novel Hydrophilic Gasket Used in Composite Geomembrane Vertical Cutoff Walls and Infrastructures Exposed to Contaminated Groundwater |
| title_full | Swelling Behavior and Flow Rates of a Novel Hydrophilic Gasket Used in Composite Geomembrane Vertical Cutoff Walls and Infrastructures Exposed to Contaminated Groundwater |
| title_fullStr | Swelling Behavior and Flow Rates of a Novel Hydrophilic Gasket Used in Composite Geomembrane Vertical Cutoff Walls and Infrastructures Exposed to Contaminated Groundwater |
| title_full_unstemmed | Swelling Behavior and Flow Rates of a Novel Hydrophilic Gasket Used in Composite Geomembrane Vertical Cutoff Walls and Infrastructures Exposed to Contaminated Groundwater |
| title_short | Swelling Behavior and Flow Rates of a Novel Hydrophilic Gasket Used in Composite Geomembrane Vertical Cutoff Walls and Infrastructures Exposed to Contaminated Groundwater |
| title_sort | swelling behavior and flow rates of a novel hydrophilic gasket used in composite geomembrane vertical cutoff walls and infrastructures exposed to contaminated groundwater |
| topic | hydrophilic gasket swelling ratio model apparatus flow rates relaxation sodium polyacrylate |
| url | https://www.mdpi.com/2075-5309/12/12/2207 |
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