Effect of Bentonite Content and Hydration Time on Mechanical Properties of Sand–Bentonite Mixture
The bentonite is commonly used mixed with soils for groundwater retention and waste contaminant facilities. The incorporation of bentonite could significantly reduce hydraulic conductivity. In this study, the effects of bentonite content, hydration time and effective confining pressure on the static...
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MDPI AG
2021-12-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/11/24/12001 |
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| author | Yue Qin Dongsheng Xu Borana Lalit |
| author_facet | Yue Qin Dongsheng Xu Borana Lalit |
| author_sort | Yue Qin |
| collection | DOAJ |
| description | The bentonite is commonly used mixed with soils for groundwater retention and waste contaminant facilities. The incorporation of bentonite could significantly reduce hydraulic conductivity. In this study, the effects of bentonite content, hydration time and effective confining pressure on the static properties of a sand–bentonite mixture were studied using experimental and numerical methods. Firstly, a large number of drainage static triaxial tests on the sand–bentonite mixture with various bentonite contents were conducted. The test results show that the increase in bentonite content and hydration time leads to a slight decrease in shear strength and initial tangent modulus of the sand–bentonite mixture. The presence of bentonite reduces the shear shrinkage and dilatancy trend of the mixture. The cohesion of the mixture increases with the increase in bentonite content and hydration time, but the internal friction angle decreases correspondingly. The hydration of bentonite on the surface of sand particles changes the contact form between particles. The bentonite slurry between pores of the sand skeleton also affects the mechanical behavior of the sand–bentonite mixture. Then, a series of 3D discrete element models were established for numerical simulations of drainage static triaxial tests. The numerical model parameters were calibrated by experimental results. The meso-mechanism of bentonite content affecting the mechanical behavior was revealed according to the contact force distribution between particles. The research results are helpful to understand further the mechanism of bentonite on the mechanical properties of the sand–bentonite mixture. |
| first_indexed | 2024-03-10T04:36:19Z |
| format | Article |
| id | doaj.art-10930b2b628644bdb2b233517616ef5f |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T04:36:19Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
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| series | Applied Sciences |
| spelling | doaj.art-10930b2b628644bdb2b233517616ef5f2023-11-23T03:41:41ZengMDPI AGApplied Sciences2076-34172021-12-0111241200110.3390/app112412001Effect of Bentonite Content and Hydration Time on Mechanical Properties of Sand–Bentonite MixtureYue Qin0Dongsheng Xu1Borana Lalit2School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, ChinaSchool of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, ChinaDepartment of Civil Engineering, Indian Institute of Technology Indore, Simrol, Indore 452020, IndiaThe bentonite is commonly used mixed with soils for groundwater retention and waste contaminant facilities. The incorporation of bentonite could significantly reduce hydraulic conductivity. In this study, the effects of bentonite content, hydration time and effective confining pressure on the static properties of a sand–bentonite mixture were studied using experimental and numerical methods. Firstly, a large number of drainage static triaxial tests on the sand–bentonite mixture with various bentonite contents were conducted. The test results show that the increase in bentonite content and hydration time leads to a slight decrease in shear strength and initial tangent modulus of the sand–bentonite mixture. The presence of bentonite reduces the shear shrinkage and dilatancy trend of the mixture. The cohesion of the mixture increases with the increase in bentonite content and hydration time, but the internal friction angle decreases correspondingly. The hydration of bentonite on the surface of sand particles changes the contact form between particles. The bentonite slurry between pores of the sand skeleton also affects the mechanical behavior of the sand–bentonite mixture. Then, a series of 3D discrete element models were established for numerical simulations of drainage static triaxial tests. The numerical model parameters were calibrated by experimental results. The meso-mechanism of bentonite content affecting the mechanical behavior was revealed according to the contact force distribution between particles. The research results are helpful to understand further the mechanism of bentonite on the mechanical properties of the sand–bentonite mixture.https://www.mdpi.com/2076-3417/11/24/12001sand–bentonite mixturebentonite contenthydration timemechanical behaviordiscrete element method (DEM) |
| spellingShingle | Yue Qin Dongsheng Xu Borana Lalit Effect of Bentonite Content and Hydration Time on Mechanical Properties of Sand–Bentonite Mixture Applied Sciences sand–bentonite mixture bentonite content hydration time mechanical behavior discrete element method (DEM) |
| title | Effect of Bentonite Content and Hydration Time on Mechanical Properties of Sand–Bentonite Mixture |
| title_full | Effect of Bentonite Content and Hydration Time on Mechanical Properties of Sand–Bentonite Mixture |
| title_fullStr | Effect of Bentonite Content and Hydration Time on Mechanical Properties of Sand–Bentonite Mixture |
| title_full_unstemmed | Effect of Bentonite Content and Hydration Time on Mechanical Properties of Sand–Bentonite Mixture |
| title_short | Effect of Bentonite Content and Hydration Time on Mechanical Properties of Sand–Bentonite Mixture |
| title_sort | effect of bentonite content and hydration time on mechanical properties of sand bentonite mixture |
| topic | sand–bentonite mixture bentonite content hydration time mechanical behavior discrete element method (DEM) |
| url | https://www.mdpi.com/2076-3417/11/24/12001 |
| work_keys_str_mv | AT yueqin effectofbentonitecontentandhydrationtimeonmechanicalpropertiesofsandbentonitemixture AT dongshengxu effectofbentonitecontentandhydrationtimeonmechanicalpropertiesofsandbentonitemixture AT boranalalit effectofbentonitecontentandhydrationtimeonmechanicalpropertiesofsandbentonitemixture |