Investigation on the Microstructure, Unconfined Compressive Strength, and Thermal Conductivity of Compacted CDG Soil by MICP Treatment during Curing.
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| Title: | Investigation on the Microstructure, Unconfined Compressive Strength, and Thermal Conductivity of Compacted CDG Soil by MICP Treatment during Curing. |
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| Authors: | Wang, Han-Lin1 (AUTHOR) wanghanlin@hnu.edu.cn, Pathak, Bidur2 (AUTHOR) bidur.pathak@connect.polyu.hk, Yin, Zhen-Yu3 (AUTHOR) zhenyu.yin@polyu.edu.hk |
| Source: | Journal of Materials in Civil Engineering. Jun2023, Vol. 35 Issue 6, p1-12. 12p. |
| Subjects: | Thermal conductivity, Compressive strength, Microstructure, Calcium carbonate, Scanning electron microscopy |
| Abstract: | As an eco-friendly treatment method, the microbially induced calcite precipitation (MICP) approach has been widely adopted in sand, but its use on compacted fine-grained soils remains scarce. In this study, compacted completely decomposed granite (CDG) soils at both the dry and wet side of the optimum water content (dry- and wet-of-optimum) were treated by the MICP approach, using a bacterial suspension and chemical reagents at fixed concentrations. After various curing periods, the microstructure (by scanning electron microscopy testing), the produced calcium carbonate content, the unconfined compressive strength (UCS), and the thermal conductivity were analyzed through a series of laboratory tests. The testing results indicate that the sample at dry-of-optimum exhibits a flocculated microstructure, while a dispersed microstructure is shown for the sample at wet-of-optimum. The calcium carbonate content increases with the curing period until reaching a stable value at around 6 days' curing. After 6 days' curing, the MICP process is relatively static, without significant amounts of calcium carbonate produced. With this treatment, the UCS of the sample is improved, where higher efficiency was observed for the sample at wet-of-optimum conditions. The variation of UCS for the MICP-treated samples with respect to the curing period follows the same trend as that of calcium carbonate content. At dry-of-optimum, the air-solid phases control the heat transfer in the MICP-treated samples with a discontinuous water phase, leading to insignificant effects of the MICP treatment on the thermal conductivity. In contrast, the water-solid phases dominate the heat transfer in the MICP-treated samples at wet-of-optimum, resulting in variation of the thermal conductivity with the curing period similar to that for the calcium carbonate content. [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of Materials in Civil Engineering is the property of American Society of Civil Engineers and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 163135674 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Investigation on the Microstructure, Unconfined Compressive Strength, and Thermal Conductivity of Compacted CDG Soil by MICP Treatment during Curing. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Wang%2C+Han-Lin%22">Wang, Han-Lin</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> wanghanlin@hnu.edu.cn</i><br /><searchLink fieldCode="AR" term="%22Pathak%2C+Bidur%22">Pathak, Bidur</searchLink><relatesTo>2</relatesTo> (AUTHOR)<i> bidur.pathak@connect.polyu.hk</i><br /><searchLink fieldCode="AR" term="%22Yin%2C+Zhen-Yu%22">Yin, Zhen-Yu</searchLink><relatesTo>3</relatesTo> (AUTHOR)<i> zhenyu.yin@polyu.edu.hk</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Materials+in+Civil+Engineering%22">Journal of Materials in Civil Engineering</searchLink>. Jun2023, Vol. 35 Issue 6, p1-12. 12p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Thermal+conductivity%22">Thermal conductivity</searchLink><br /><searchLink fieldCode="DE" term="%22Compressive+strength%22">Compressive strength</searchLink><br /><searchLink fieldCode="DE" term="%22Microstructure%22">Microstructure</searchLink><br /><searchLink fieldCode="DE" term="%22Calcium+carbonate%22">Calcium carbonate</searchLink><br /><searchLink fieldCode="DE" term="%22Scanning+electron+microscopy%22">Scanning electron microscopy</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: As an eco-friendly treatment method, the microbially induced calcite precipitation (MICP) approach has been widely adopted in sand, but its use on compacted fine-grained soils remains scarce. In this study, compacted completely decomposed granite (CDG) soils at both the dry and wet side of the optimum water content (dry- and wet-of-optimum) were treated by the MICP approach, using a bacterial suspension and chemical reagents at fixed concentrations. After various curing periods, the microstructure (by scanning electron microscopy testing), the produced calcium carbonate content, the unconfined compressive strength (UCS), and the thermal conductivity were analyzed through a series of laboratory tests. The testing results indicate that the sample at dry-of-optimum exhibits a flocculated microstructure, while a dispersed microstructure is shown for the sample at wet-of-optimum. The calcium carbonate content increases with the curing period until reaching a stable value at around 6 days' curing. After 6 days' curing, the MICP process is relatively static, without significant amounts of calcium carbonate produced. With this treatment, the UCS of the sample is improved, where higher efficiency was observed for the sample at wet-of-optimum conditions. The variation of UCS for the MICP-treated samples with respect to the curing period follows the same trend as that of calcium carbonate content. At dry-of-optimum, the air-solid phases control the heat transfer in the MICP-treated samples with a discontinuous water phase, leading to insignificant effects of the MICP treatment on the thermal conductivity. In contrast, the water-solid phases dominate the heat transfer in the MICP-treated samples at wet-of-optimum, resulting in variation of the thermal conductivity with the curing period similar to that for the calcium carbonate content. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Materials in Civil Engineering is the property of American Society of Civil Engineers and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1061/JMCEE7.MTENG-14901 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 12 StartPage: 1 Subjects: – SubjectFull: Thermal conductivity Type: general – SubjectFull: Compressive strength Type: general – SubjectFull: Microstructure Type: general – SubjectFull: Calcium carbonate Type: general – SubjectFull: Scanning electron microscopy Type: general Titles: – TitleFull: Investigation on the Microstructure, Unconfined Compressive Strength, and Thermal Conductivity of Compacted CDG Soil by MICP Treatment during Curing. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Wang, Han-Lin – PersonEntity: Name: NameFull: Pathak, Bidur – PersonEntity: Name: NameFull: Yin, Zhen-Yu IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 06 Text: Jun2023 Type: published Y: 2023 Identifiers: – Type: issn-print Value: 08991561 Numbering: – Type: volume Value: 35 – Type: issue Value: 6 Titles: – TitleFull: Journal of Materials in Civil Engineering Type: main |
| ResultId | 1 |
