Screening Additives for Amending Compacted Clay Covers to Enhance Diffusion Barrier Properties and Moisture Retention Performance
The cover systems in contaminated sites have some problems, including desiccation cracks, which would lead to degradation of the barrier performance. This study presented a systemic laboratory experimental investigation on the liquid–plastic limit, moisture retention, hydraulic conductivity (<i&g...
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MDPI AG
2022-07-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/14/7341 |
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| author | Min Wang Jiaming Wen Heng Zhuang Weiyi Xia Ningjun Jiang Yanjun Du |
| author_facet | Min Wang Jiaming Wen Heng Zhuang Weiyi Xia Ningjun Jiang Yanjun Du |
| author_sort | Min Wang |
| collection | DOAJ |
| description | The cover systems in contaminated sites have some problems, including desiccation cracks, which would lead to degradation of the barrier performance. This study presented a systemic laboratory experimental investigation on the liquid–plastic limit, moisture retention, hydraulic conductivity (<i>k</i>), and gas diffusion barrier properties of amended compacted clay by attapulgite and diatomite for controlling desiccation cracks and migration of water and volatile organic compounds (VOCs). The results showed that the attapulgite could enhance the moisture retention and liquid limit of amended compacted clay. Diatomite could reduce the gas diffusion coefficient (<i>D<sub>θ</sub></i>) significantly. The compacted clay amended by the dual-additives component of attapulgite and diatomite could enhance the liquid limit, moisture retention percent, gas barrier property, and hydraulic performance compared with the unamended clay. Based on the experimental data obtained, the dosage of additives was targeted to be 5%. The moisture retention percent of dual-additives (attapulgite 4% and diatomite 1%) amended clay increased by 82%, the <i>k</i> decreased by 25%, and the <i>D<sub>θ</sub></i> decreased by 42% compared with unamended clay. Scanning electron microscopy (SEM), BET-specific surface area test method (BET), Mercury Intrusion Porosimetry (MIP), and thermogravimetric analysis (TGA) indicated the enhancement mechanism of additives-amended compacted clay. |
| first_indexed | 2024-03-09T12:16:44Z |
| format | Article |
| id | doaj.art-526c0a93524b40cc82786d3957dbfe4f |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-09T12:16:44Z |
| publishDate | 2022-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-526c0a93524b40cc82786d3957dbfe4f2023-11-30T22:46:07ZengMDPI AGApplied Sciences2076-34172022-07-011214734110.3390/app12147341Screening Additives for Amending Compacted Clay Covers to Enhance Diffusion Barrier Properties and Moisture Retention PerformanceMin Wang0Jiaming Wen1Heng Zhuang2Weiyi Xia3Ningjun Jiang4Yanjun Du5Jiangsu Key Laboratory of Urban Underground Engineering & Environmental Safety, Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, ChinaZijin (Changsha) Engineering Technology Co., Ltd., Changsha 410006, ChinaJiangsu Key Laboratory of Urban Underground Engineering & Environmental Safety, Institute of Geotechnical Engineering, Southeast University, Nanjing 210096, ChinaJiangsu Environmental Engineering Technology Co., Ltd., Nanjing 210019, 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 cover systems in contaminated sites have some problems, including desiccation cracks, which would lead to degradation of the barrier performance. This study presented a systemic laboratory experimental investigation on the liquid–plastic limit, moisture retention, hydraulic conductivity (<i>k</i>), and gas diffusion barrier properties of amended compacted clay by attapulgite and diatomite for controlling desiccation cracks and migration of water and volatile organic compounds (VOCs). The results showed that the attapulgite could enhance the moisture retention and liquid limit of amended compacted clay. Diatomite could reduce the gas diffusion coefficient (<i>D<sub>θ</sub></i>) significantly. The compacted clay amended by the dual-additives component of attapulgite and diatomite could enhance the liquid limit, moisture retention percent, gas barrier property, and hydraulic performance compared with the unamended clay. Based on the experimental data obtained, the dosage of additives was targeted to be 5%. The moisture retention percent of dual-additives (attapulgite 4% and diatomite 1%) amended clay increased by 82%, the <i>k</i> decreased by 25%, and the <i>D<sub>θ</sub></i> decreased by 42% compared with unamended clay. Scanning electron microscopy (SEM), BET-specific surface area test method (BET), Mercury Intrusion Porosimetry (MIP), and thermogravimetric analysis (TGA) indicated the enhancement mechanism of additives-amended compacted clay.https://www.mdpi.com/2076-3417/12/14/7341additivescompacted clay covermoisture retentiongas diffusion barrierhydraulic conductivity |
| spellingShingle | Min Wang Jiaming Wen Heng Zhuang Weiyi Xia Ningjun Jiang Yanjun Du Screening Additives for Amending Compacted Clay Covers to Enhance Diffusion Barrier Properties and Moisture Retention Performance Applied Sciences additives compacted clay cover moisture retention gas diffusion barrier hydraulic conductivity |
| title | Screening Additives for Amending Compacted Clay Covers to Enhance Diffusion Barrier Properties and Moisture Retention Performance |
| title_full | Screening Additives for Amending Compacted Clay Covers to Enhance Diffusion Barrier Properties and Moisture Retention Performance |
| title_fullStr | Screening Additives for Amending Compacted Clay Covers to Enhance Diffusion Barrier Properties and Moisture Retention Performance |
| title_full_unstemmed | Screening Additives for Amending Compacted Clay Covers to Enhance Diffusion Barrier Properties and Moisture Retention Performance |
| title_short | Screening Additives for Amending Compacted Clay Covers to Enhance Diffusion Barrier Properties and Moisture Retention Performance |
| title_sort | screening additives for amending compacted clay covers to enhance diffusion barrier properties and moisture retention performance |
| topic | additives compacted clay cover moisture retention gas diffusion barrier hydraulic conductivity |
| url | https://www.mdpi.com/2076-3417/12/14/7341 |
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