Influence of Five Additives on No Loading Swelling Potential of Red Clay
In this study, cement, zeolite powder and three industrial by-products (blast furnace slag, steel slag, and fly ash) were selected as additives to study their effects on the swelling potential of red clay with different curing ages and dosages. At the same time, the mechanism of additives reducing t...
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| Format: | Article |
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MDPI AG
2022-03-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/7/3455 |
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| author | Bing Yue Ziye Zhao Zengzhen Qian |
| author_facet | Bing Yue Ziye Zhao Zengzhen Qian |
| author_sort | Bing Yue |
| collection | DOAJ |
| description | In this study, cement, zeolite powder and three industrial by-products (blast furnace slag, steel slag, and fly ash) were selected as additives to study their effects on the swelling potential of red clay with different curing ages and dosages. At the same time, the mechanism of additives reducing the swelling potential of red clay was analyzed by scanning electron microscope (SEM) and X-ray fluorescence (XRF) tests. The X-ray diffraction (XRD) test was used to detect the clay mineral content of the red clay specimens before and after the modification to determine the change in the clay mineral content of the specimens. The direct shear test was used to explore the influence of additives on the strength of red clay. The results show that with 9% cement content, the no loading swelling potential of specimens can be reduced by 82.5% under 28 days of curing, and the cohesion of the specimens can be greatly increased by 82%. However, the specimens with cement have an increase in no loading swelling potential under the condition of no curing. In contrast, when steel slag is used as an additive to modify the swelling properties of red clay, the swelling potential can be reduced without curing, but the addition of steel slag will reduce the cohesive strength of specimens. XRD testing shows that the clay mineral composition in cement-modified specimens and steel slag-modified specimens experienced a relative change, the relative content of montmorillonite and illite decreased, and the relative content of kaolinite increased. Combined with SEM and XRF test results, it is concluded that cement’s reduction in the swelling potential of red clay depends on pozzolanic reaction products filling the pores in specimens and bonding clay particles, so as to reduce the permeability of red clay and increase the resistance during swelling. The addition of cement can also convert hydrophilic clay minerals into nonhydrophilic clay minerals. Compared with cement, the reduction in swelling potential caused by steel slag mainly depends on the adsorption of ions to reduce the adsorption of water molecules on the surface of clay slices. |
| first_indexed | 2024-03-09T12:07:32Z |
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| language | English |
| last_indexed | 2024-03-09T12:07:32Z |
| publishDate | 2022-03-01 |
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| series | Applied Sciences |
| spelling | doaj.art-4c915c6eba1a496b879ce0f92d7813242023-11-30T22:55:58ZengMDPI AGApplied Sciences2076-34172022-03-01127345510.3390/app12073455Influence of Five Additives on No Loading Swelling Potential of Red ClayBing Yue0Ziye Zhao1Zengzhen Qian2School of Engineering and Technology, China University of Geosciences (Beijing), Beijing 100083, ChinaSchool of Engineering and Technology, China University of Geosciences (Beijing), Beijing 100083, ChinaSchool of Engineering and Technology, China University of Geosciences (Beijing), Beijing 100083, ChinaIn this study, cement, zeolite powder and three industrial by-products (blast furnace slag, steel slag, and fly ash) were selected as additives to study their effects on the swelling potential of red clay with different curing ages and dosages. At the same time, the mechanism of additives reducing the swelling potential of red clay was analyzed by scanning electron microscope (SEM) and X-ray fluorescence (XRF) tests. The X-ray diffraction (XRD) test was used to detect the clay mineral content of the red clay specimens before and after the modification to determine the change in the clay mineral content of the specimens. The direct shear test was used to explore the influence of additives on the strength of red clay. The results show that with 9% cement content, the no loading swelling potential of specimens can be reduced by 82.5% under 28 days of curing, and the cohesion of the specimens can be greatly increased by 82%. However, the specimens with cement have an increase in no loading swelling potential under the condition of no curing. In contrast, when steel slag is used as an additive to modify the swelling properties of red clay, the swelling potential can be reduced without curing, but the addition of steel slag will reduce the cohesive strength of specimens. XRD testing shows that the clay mineral composition in cement-modified specimens and steel slag-modified specimens experienced a relative change, the relative content of montmorillonite and illite decreased, and the relative content of kaolinite increased. Combined with SEM and XRF test results, it is concluded that cement’s reduction in the swelling potential of red clay depends on pozzolanic reaction products filling the pores in specimens and bonding clay particles, so as to reduce the permeability of red clay and increase the resistance during swelling. The addition of cement can also convert hydrophilic clay minerals into nonhydrophilic clay minerals. Compared with cement, the reduction in swelling potential caused by steel slag mainly depends on the adsorption of ions to reduce the adsorption of water molecules on the surface of clay slices.https://www.mdpi.com/2076-3417/12/7/3455red clayexpansive soilcementsteel slagmodificationswelling potential |
| spellingShingle | Bing Yue Ziye Zhao Zengzhen Qian Influence of Five Additives on No Loading Swelling Potential of Red Clay Applied Sciences red clay expansive soil cement steel slag modification swelling potential |
| title | Influence of Five Additives on No Loading Swelling Potential of Red Clay |
| title_full | Influence of Five Additives on No Loading Swelling Potential of Red Clay |
| title_fullStr | Influence of Five Additives on No Loading Swelling Potential of Red Clay |
| title_full_unstemmed | Influence of Five Additives on No Loading Swelling Potential of Red Clay |
| title_short | Influence of Five Additives on No Loading Swelling Potential of Red Clay |
| title_sort | influence of five additives on no loading swelling potential of red clay |
| topic | red clay expansive soil cement steel slag modification swelling potential |
| url | https://www.mdpi.com/2076-3417/12/7/3455 |
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