Effect of coral sand powders and seawater salinity on the impact mechanical properties of cemented coral sand
Coral sand is one kind of the important building materials in coral reef engineering practice. The use of cement as a stabilizing agent can significantly improve the mechanical properties of coral sands and is widely applied in the subbase engineering construction in coral reef islands. Cement-stabi...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-10-01
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| Series: | Soils and Foundations |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0038080622001147 |
| _version_ | 1828100124682747904 |
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| author | Jinjian Yang Dongsheng Xu Jianhua Shen Houzhen Wei Ren Wang Xianbo Xiao |
| author_facet | Jinjian Yang Dongsheng Xu Jianhua Shen Houzhen Wei Ren Wang Xianbo Xiao |
| author_sort | Jinjian Yang |
| collection | DOAJ |
| description | Coral sand is one kind of the important building materials in coral reef engineering practice. The use of cement as a stabilizing agent can significantly improve the mechanical properties of coral sands and is widely applied in the subbase engineering construction in coral reef islands. Cement-stabilized coral sand structures may contain high contents of fine coral particles and salinity because of the high crushability of coral sands and the existence of seawater surrounding them. In this study, the effects of coral sand powders and seawater salinity on the dynamic mechanical properties of cemented coral sand (CCS) were investigated through the split Hopkinson pressure bar (SHPB) tests and Scanning Electron Microscope (SEM) analysis. It was found that the strength (i.e., the peak stress) of CCS specimens increased firstly and then decreased with the increase of powder content. The specimens reached the maximum peak stress when 3% powder content was included. The initial improvement of CCS strength was attributed to the pore-filling effect of coral powders, namely, the micro pores of the CCS specimens could be more effectively filled with higher percentages of coral powders being used in the experiments. However, excessive coral powders resulted in the reduction of specimen strength because these powders could easily be cemented into agglomerates by absorbing water from the specimens. These agglomerates could reduce the cementation strength between the coarse coral particles and the cement. Meanwhile, the peak stress of CCS specimens was found to be negatively correlated with the average strain rate and the ultimate strain. The degree of specimen fracture was found to be correlated with the amount of specific energy absorption during the tests. Furthermore, the “sulfate attack” caused by the inclusion of salinity of water had different influences on the CCS specimens with different coral powder contents. The ettringite and gypsum produced in “sulfate attack” could fill the pores and lead to cracking of the specimens, significantly affecting the specimen strength. |
| first_indexed | 2024-04-11T08:24:27Z |
| format | Article |
| id | doaj.art-3d90a48246e340a1bedea0fbc76a1d60 |
| institution | Directory Open Access Journal |
| issn | 2524-1788 |
| language | English |
| last_indexed | 2024-04-11T08:24:27Z |
| publishDate | 2022-10-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Soils and Foundations |
| spelling | doaj.art-3d90a48246e340a1bedea0fbc76a1d602022-12-22T04:34:49ZengElsevierSoils and Foundations2524-17882022-10-01625101206Effect of coral sand powders and seawater salinity on the impact mechanical properties of cemented coral sandJinjian Yang0Dongsheng Xu1Jianhua Shen2Houzhen Wei3Ren Wang4Xianbo Xiao5School of Civil Engineering and Architecture, Guangxi University, Nanning 530004, Guangxi, ChinaSchool of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan 430070, Hubei, China; Corresponding author.State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, Hubei, ChinaState Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, Hubei, ChinaSchool of Civil Engineering and Architecture, Guangxi University, Nanning 530004, Guangxi, China; State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, Hubei, ChinaHuzhou Key Laboratory of Green Building Technology, Huzhou 313002, Zhejiang, ChinaCoral sand is one kind of the important building materials in coral reef engineering practice. The use of cement as a stabilizing agent can significantly improve the mechanical properties of coral sands and is widely applied in the subbase engineering construction in coral reef islands. Cement-stabilized coral sand structures may contain high contents of fine coral particles and salinity because of the high crushability of coral sands and the existence of seawater surrounding them. In this study, the effects of coral sand powders and seawater salinity on the dynamic mechanical properties of cemented coral sand (CCS) were investigated through the split Hopkinson pressure bar (SHPB) tests and Scanning Electron Microscope (SEM) analysis. It was found that the strength (i.e., the peak stress) of CCS specimens increased firstly and then decreased with the increase of powder content. The specimens reached the maximum peak stress when 3% powder content was included. The initial improvement of CCS strength was attributed to the pore-filling effect of coral powders, namely, the micro pores of the CCS specimens could be more effectively filled with higher percentages of coral powders being used in the experiments. However, excessive coral powders resulted in the reduction of specimen strength because these powders could easily be cemented into agglomerates by absorbing water from the specimens. These agglomerates could reduce the cementation strength between the coarse coral particles and the cement. Meanwhile, the peak stress of CCS specimens was found to be negatively correlated with the average strain rate and the ultimate strain. The degree of specimen fracture was found to be correlated with the amount of specific energy absorption during the tests. Furthermore, the “sulfate attack” caused by the inclusion of salinity of water had different influences on the CCS specimens with different coral powder contents. The ettringite and gypsum produced in “sulfate attack” could fill the pores and lead to cracking of the specimens, significantly affecting the specimen strength.http://www.sciencedirect.com/science/article/pii/S0038080622001147Cemented coral sandCoral sand powderSeawater salinitySplit Hopkinson pressure bar testDynamic behavior |
| spellingShingle | Jinjian Yang Dongsheng Xu Jianhua Shen Houzhen Wei Ren Wang Xianbo Xiao Effect of coral sand powders and seawater salinity on the impact mechanical properties of cemented coral sand Soils and Foundations Cemented coral sand Coral sand powder Seawater salinity Split Hopkinson pressure bar test Dynamic behavior |
| title | Effect of coral sand powders and seawater salinity on the impact mechanical properties of cemented coral sand |
| title_full | Effect of coral sand powders and seawater salinity on the impact mechanical properties of cemented coral sand |
| title_fullStr | Effect of coral sand powders and seawater salinity on the impact mechanical properties of cemented coral sand |
| title_full_unstemmed | Effect of coral sand powders and seawater salinity on the impact mechanical properties of cemented coral sand |
| title_short | Effect of coral sand powders and seawater salinity on the impact mechanical properties of cemented coral sand |
| title_sort | effect of coral sand powders and seawater salinity on the impact mechanical properties of cemented coral sand |
| topic | Cemented coral sand Coral sand powder Seawater salinity Split Hopkinson pressure bar test Dynamic behavior |
| url | http://www.sciencedirect.com/science/article/pii/S0038080622001147 |
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