Experimental Study on the Road Performance of Phosphogypsum-Modified Lime-Fly Ash Stabilized Red Clay
To assess the impact of solid waste phosphogypsum on the road performance of lime-fly ash-stabilized red clay, we conducted comprehensive tests on the road performance, swelling and shrinkage characteristics, and mechanical properties of lime-fly ash soil with varying phosphogypsum content and curin...
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| Format: | Article |
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MDPI AG
2023-11-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/13/23/12689 |
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| author | Shibin Huang Yanzhou Ma Jiaquan Wang Zhinan Lin Tianxin Chen |
| author_facet | Shibin Huang Yanzhou Ma Jiaquan Wang Zhinan Lin Tianxin Chen |
| author_sort | Shibin Huang |
| collection | DOAJ |
| description | To assess the impact of solid waste phosphogypsum on the road performance of lime-fly ash-stabilized red clay, we conducted comprehensive tests on the road performance, swelling and shrinkage characteristics, and mechanical properties of lime-fly ash soil with varying phosphogypsum content and curing age. Additionally, we analyzed the microstructure and composition changes using scanning electron microscopy and X-ray diffraction tests. The results revealed that phosphogypsum significantly enhances the early strength and moisture stability of lime-fly ash soil. The mechanical properties of lime-fly ash soil continue to improve with increased curing age, with performance improvements tapering off after 60 days and eventually stabilizing. Moreover, as the phosphogypsum content increases, the unconfined compressive strength (UCS), splitting strength, and CBR value of the lime-fly ash soil initially increase and then decrease. The optimal mixing ratio was determined to be 4% phosphogypsum, resulting in a 7-day UCS increase of 67.2%, a 28-day UCS increase of 3 times, and a 28-day splitting strength increase of 4.3 times. The moisture stability coefficient also exhibited a 43% increase after 7 days, and its anti-disintegration ability was enhanced, reaching 0.91 after 28 days, which meets the specified standards. Microscopic analysis revealed that the addition of phosphogypsum improved the overall integrity of the lime-fly ash soil, and the formation of ettringite effectively filled the soil’s pores. However, excessive ettringite caused increased expansion and deformation. To optimize the use of phosphogypsum-modified lime-fly ash-stabilized red clay as subgrade filler, it is advisable to incorporate additives to further reduce swelling deformation. |
| first_indexed | 2024-03-09T01:55:56Z |
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| id | doaj.art-a1f1336486594e888b265bdab8ef10fa |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-09T01:55:56Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-a1f1336486594e888b265bdab8ef10fa2023-12-08T15:11:25ZengMDPI AGApplied Sciences2076-34172023-11-0113231268910.3390/app132312689Experimental Study on the Road Performance of Phosphogypsum-Modified Lime-Fly Ash Stabilized Red ClayShibin Huang0Yanzhou Ma1Jiaquan Wang2Zhinan Lin3Tianxin Chen4Guangxi University Key Laboratory of Disaster Prevention and Mitigation and Prestress Technology, Guangxi University of Science and Technology, Liuzhou 545006, ChinaGuangxi University Key Laboratory of Disaster Prevention and Mitigation and Prestress Technology, Guangxi University of Science and Technology, Liuzhou 545006, ChinaGuangxi University Key Laboratory of Disaster Prevention and Mitigation and Prestress Technology, Guangxi University of Science and Technology, Liuzhou 545006, ChinaGuangxi University Key Laboratory of Disaster Prevention and Mitigation and Prestress Technology, Guangxi University of Science and Technology, Liuzhou 545006, ChinaGuangxi University Key Laboratory of Disaster Prevention and Mitigation and Prestress Technology, Guangxi University of Science and Technology, Liuzhou 545006, ChinaTo assess the impact of solid waste phosphogypsum on the road performance of lime-fly ash-stabilized red clay, we conducted comprehensive tests on the road performance, swelling and shrinkage characteristics, and mechanical properties of lime-fly ash soil with varying phosphogypsum content and curing age. Additionally, we analyzed the microstructure and composition changes using scanning electron microscopy and X-ray diffraction tests. The results revealed that phosphogypsum significantly enhances the early strength and moisture stability of lime-fly ash soil. The mechanical properties of lime-fly ash soil continue to improve with increased curing age, with performance improvements tapering off after 60 days and eventually stabilizing. Moreover, as the phosphogypsum content increases, the unconfined compressive strength (UCS), splitting strength, and CBR value of the lime-fly ash soil initially increase and then decrease. The optimal mixing ratio was determined to be 4% phosphogypsum, resulting in a 7-day UCS increase of 67.2%, a 28-day UCS increase of 3 times, and a 28-day splitting strength increase of 4.3 times. The moisture stability coefficient also exhibited a 43% increase after 7 days, and its anti-disintegration ability was enhanced, reaching 0.91 after 28 days, which meets the specified standards. Microscopic analysis revealed that the addition of phosphogypsum improved the overall integrity of the lime-fly ash soil, and the formation of ettringite effectively filled the soil’s pores. However, excessive ettringite caused increased expansion and deformation. To optimize the use of phosphogypsum-modified lime-fly ash-stabilized red clay as subgrade filler, it is advisable to incorporate additives to further reduce swelling deformation.https://www.mdpi.com/2076-3417/13/23/12689phosphogypsumlime-ash stabilized red clayroad performancemoisture stabilitymicroscopic mechanism |
| spellingShingle | Shibin Huang Yanzhou Ma Jiaquan Wang Zhinan Lin Tianxin Chen Experimental Study on the Road Performance of Phosphogypsum-Modified Lime-Fly Ash Stabilized Red Clay Applied Sciences phosphogypsum lime-ash stabilized red clay road performance moisture stability microscopic mechanism |
| title | Experimental Study on the Road Performance of Phosphogypsum-Modified Lime-Fly Ash Stabilized Red Clay |
| title_full | Experimental Study on the Road Performance of Phosphogypsum-Modified Lime-Fly Ash Stabilized Red Clay |
| title_fullStr | Experimental Study on the Road Performance of Phosphogypsum-Modified Lime-Fly Ash Stabilized Red Clay |
| title_full_unstemmed | Experimental Study on the Road Performance of Phosphogypsum-Modified Lime-Fly Ash Stabilized Red Clay |
| title_short | Experimental Study on the Road Performance of Phosphogypsum-Modified Lime-Fly Ash Stabilized Red Clay |
| title_sort | experimental study on the road performance of phosphogypsum modified lime fly ash stabilized red clay |
| topic | phosphogypsum lime-ash stabilized red clay road performance moisture stability microscopic mechanism |
| url | https://www.mdpi.com/2076-3417/13/23/12689 |
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