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Xi Y, Sun M, Li H, Li G, Wang P, Li L. Permeability and Disintegration Characteristics of Loess Solidified by Guar Gum and Basalt Fiber. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3150. [PMID: 38998233 PMCID: PMC11242473 DOI: 10.3390/ma17133150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 06/15/2024] [Accepted: 06/19/2024] [Indexed: 07/14/2024]
Abstract
Loess has the characteristics of loose, large pore ratio, and strong water sensitivity. Once it encounters water, its structure is damaged easily and its strength is degraded, causing a degree of subgrade settlement. The water sensitivity of loess can be evaluated by permeability and disintegration tests. This study analyzes the effects of guar gum content, basalt fiber content, and basalt fiber length on the permeability and disintegration characteristics of solidified loess. The microstructure of loess was studied through scanning electron microscopy (SEM) testing, revealing the synergistic solidification mechanism of guar gum and basalt fibers. A permeability model was established through regression analysis with guar gum content, confining pressure, basalt fiber content, and length. The research results indicate that the addition of guar gum reduces the permeability of solidified loess, the addition of fiber improves the overall strength, and the addition of guar gum and basalt fiber improves the disintegration resistance. When the guar gum content is 1.00%, the permeability coefficient and disintegration rate of solidified soil are reduced by 50.50% and 94.10%, respectively. When the guar gum content is 1.00%, the basalt fiber length is 12 mm, and the fiber content is 1.00%, the permeability of the solidified soil decreases by 31.9%, and the disintegration rate is 4.80%. The permeability model has a good fitting effect and is suitable for predicting the permeability of loess reinforced with guar gum and basalt fiber composite. This research is of vital theoretical worth and great scientific significance for guidelines on practicing loess solidification engineering.
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Affiliation(s)
- Yu Xi
- Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, China
| | - Mingming Sun
- Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, China
| | - Huanhuan Li
- School of Civil Engineering and Architecture, NingboTech University, Ningbo 315100, China
| | - Gang Li
- Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, China
| | - Pengzhou Wang
- China Construction Fourth Engineering Division Corp., Ltd., Guangzhou 511400, China
| | - Li Li
- Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, China
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Xi Y, Sun M, Li H, Li G, Wang P, Li L. Study on the Shear Strength of Loess Solidified by Guar Gum and Basalt Fiber. MATERIALS (BASEL, SWITZERLAND) 2024; 17:3116. [PMID: 38998199 PMCID: PMC11242063 DOI: 10.3390/ma17133116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 06/18/2024] [Accepted: 06/21/2024] [Indexed: 07/14/2024]
Abstract
Loess is widely distributed in the northwest and other regions, and its unique structural forms such as large pores and strong water sensitivity lead to its collapsibility and collapse, which can easily induce slope instability. Guar gum and basalt fiber are natural green materials. For these reasons, this study investigated the solidification of loess by combining guar gum and basalt fiber and analyzed the impact of the guar gum content, fiber length, and fiber content on the soil shearing strength. Using scanning electron microscopy (SEM), the microstructure of loess was examined, revealing the synergistic solidification mechanism of guar gum and basalt fibers. On this basis, a shear strength model was established through regression analysis with fiber length, guar gum content, and fiber content. The results indicate that adding guar gum and basalt fiber increases soil cohesion, as do fiber length, guar gum content, and fiber content. When the fiber length was 12 mm, the fiber content was 1.00%, and the guar gum content was equal to 0.50%, 0.75%, or 1.00%, the peak strength of the solidified loess increased by 82.80%, 85.90%, and 90.40%, respectively. According to the shear strength model, the predicted and test data of the shear strength of solidified loess are evenly distributed on both sides of parallel lines, indicating a good fit. These findings are theoretically significant and provide practical guidance for loess solidification engineering.
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Affiliation(s)
- Yu Xi
- Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, China
| | - Mingming Sun
- Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, China
| | - Huanhuan Li
- School of Civil Engineering and Architecture, Ningbo Tech University, Ningbo 315100, China
| | - Gang Li
- Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, China
| | - Pengzhou Wang
- China Construction Fourth Engineering Division Corp., Ltd., Guangzhou 511400, China
| | - Li Li
- Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, Xijing University, Xi’an 710123, China
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Huang Z, Su Q, Liu T, Huang J, Wang X, Kaewunruen S. Full-Scale Experimental and Field Investigations into Expansion Mechanism of Foamed Polyurethane and its Lifting Behaviors for Repair and Maintenance of Railway Slab Track Systems. Polymers (Basel) 2024; 16:404. [PMID: 38337293 DOI: 10.3390/polym16030404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
Excessive settlement of the subgrade seriously reduces the service quality of slab tracks and threatens trains' running safety. While the utilization of foamed polyurethane is recognized as an effective solution, previous research on its expansion mechanism and its impact on track lifting requires further refinement. Accordingly, a series of full-scale tests, including expansion force tests on foamed polyurethane with diverse qualities and lifting tests of polyurethane grouting with varied qualities on the track structure, have been conducted. The expansion development process of foamed polyurethane is meticulously elucidated, and key expansion parameters are analyzed. Simultaneously, this research explores the lifting behavior of foamed polyurethane grouting under the slab tracks, yielding new insights into essential lifting parameters for track formation repair and maintenance. Based on the experimental data, this study proposes new empirical formulas to comprehensively describe both the expansion mechanism of foam polyurethane and its lifting behavior under the slab tracks. The outcomes of this research offer a new breakthrough for the design of lifting mechanism for maintaining slab track structures through the utilization of foam polyurethane slurry grouting, such as determining the optimal grouting quantity. In addition, these results are instrumental to the evaluation of lifting effects and service life, enhancing the circular economy of railway track systems.
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Affiliation(s)
- Zhichao Huang
- School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China
- Department of Civil Engineering, School of Engineering, University of Birmingham, Birmingham B15 2TT, UK
| | - Qian Su
- School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Ting Liu
- China Railway Construction Kunlun Investment Group Co., Ltd., Chengdu 610040, China
| | - Junjie Huang
- School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Xun Wang
- School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Sakdirat Kaewunruen
- Department of Civil Engineering, School of Engineering, University of Birmingham, Birmingham B15 2TT, UK
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Chen K, Shao D, Liu Z, Chen L, He G. Experimental study on basic engineering properties of loess improved by burnt rock. Sci Rep 2023; 13:11023. [PMID: 37419992 DOI: 10.1038/s41598-023-38083-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 07/03/2023] [Indexed: 07/09/2023] Open
Abstract
Modifying the loess foundation effectively solved the deformation and settlement of the building foundation and improved its stability. However, burnt rock-solid waste was often used as filling material and light aggregate, while there were few studies on the engineering mechanical properties of modified soil. This paper proposed a method of burnt rock solid waste-modified loess. Therefore, we conducted compression-consolidation and direct shear tests on burnt rock solid waste-modified loess under different burnt rock contents to explore its improved loess's deformation and strength characteristics. Then, we used an SEM to investigate the modified loess's micro-structures under different burnt rock contents. The results showed that as the burnt rock-solid waste particle content continued to increase, the void ratio and compressibility coefficient of the samples with different ranges of burnt rock-solid waste particles gradually decreased with rising vertical pressure, while the compressive modulus increased first, then reduced and then increased with the increase of vertical pressure; the shear strength indexes all showed an increasing trend with the increased content of burnt rock-solid waste particles; when the content of burnt rock-solid waste particles was 50%, the compressibility of mixed soil was the lowest, the shear strength was the largest, and the compaction effect and shear resistance were the best. However, when the content of burnt rock particles was 10-20%, the shear strength of the soil improved significantly within the content range. The mechanism of burnt rock-solid waste to enhance the strength of the loess structure was mainly to reduce the porosity and average area of soil, significantly improve the strength and stability of mixed soil particles, and thus significantly improve the mechanical properties of soil. The results of this research will provide technical support for safe engineering construction and geological disaster prevention and control in loess areas.
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Affiliation(s)
- Kai Chen
- School of Geology and Mining Engineering, Xinjiang University, Urumqi, 830017, China.
- School of Resource and Earth Science, China University of Mining & Technology, Xuzhou, 221116, China.
- State Key Laboratory for Geomechanics and Deep Underground Engineering, Xuzhou, 221116, China.
| | - Dan Shao
- School of Geology and Mining Engineering, Xinjiang University, Urumqi, 830017, China
- Northwest Bureau of China Metallurgical Geology Bureau, Xi'an, 710000, China
| | - Zhiqi Liu
- School of Geology and Mining Engineering, Xinjiang University, Urumqi, 830017, China
| | - Lifeng Chen
- School of Geology and Mining Engineering, Xinjiang University, Urumqi, 830017, China
| | - Genyi He
- The Second Hydrology Engineering Geology Brigade of Xinjiang Bureau of Geology and Mineral Re-sources, Xinjiang, 831100, Changji, China
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Zhang X, Gao J, Qiang M, Zhang H, Li X, Long S, Gao Z, Fan H. Mechanical Characterization and Constitutive Modeling of Nano-Stabilized Soil under Uniaxial Compression. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1488. [PMID: 36837118 PMCID: PMC9961830 DOI: 10.3390/ma16041488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/06/2023] [Accepted: 02/09/2023] [Indexed: 06/18/2023]
Abstract
The stress-strain constitutive model under uniaxial compression is a basic element and important characterization method for determining physical and mechanical properties in cement-based materials research. In this study, a stress-strain constitutive model under uniaxial compression was established, which was based on a new nano-stabilized soil (NSS) through typical mechanical tests and constitutive relationship research. The results indicate that the unconfined compressive strength (UCS) of the nano-stabilized soil was enhanced with the increase in curing period and nano-stabilizer dosage, and that the strength growth rate reaches the maximum at a 12% dosage in the tested samples. The UCS of NSS under a 12% dosage is about 10~15% higher than that of ordinary stabilized soil (SS) without nano doping, and 25~40% higher compared with grade 42.5 cement-soil. The established constitutive model could accurately describe the linear-elastic and elastic-plastic deformation characteristics of NSS under uniaxial compression, which will be conducive to revealing the curve variation law of the stress-strain process. The research results could provide scientific support for the theoretical innovation and engineering application of green environmental protection materials.
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Affiliation(s)
- Xingchen Zhang
- Institute of Soil and Water Conservation, Northwest Agriculture and Forestry University, Xianyang 712100, China
- Northwest Engineering Corporation Limited, Power China, Xi’an 710065, China
| | - Jianen Gao
- Institute of Soil and Water Conservation, Northwest Agriculture and Forestry University, Xianyang 712100, China
| | - Minmin Qiang
- Northwest Engineering Corporation Limited, Power China, Xi’an 710065, China
| | - Haochen Zhang
- Northwest Engineering Corporation Limited, Power China, Xi’an 710065, China
| | - Xinghua Li
- College of Civil Engineering, Yan’an University, Yan’an 716000, China
| | - Shaobo Long
- Institute of Soil and Water Conservation, Northwest Agriculture and Forestry University, Xianyang 712100, China
| | - Zhe Gao
- College of Water Resources and Architectural Engineering, Northwest Agriculture and Forestry University, Xianyang 712100, China
| | - Henghui Fan
- College of Water Resources and Architectural Engineering, Northwest Agriculture and Forestry University, Xianyang 712100, China
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Wang W, Cheng Y, Chen H, Tan G. Polymeric Composites in Road and Bridge Engineering: Characterization, Production and Application. Polymers (Basel) 2023; 15:polym15040874. [PMID: 36850158 PMCID: PMC9966063 DOI: 10.3390/polym15040874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 02/09/2023] [Indexed: 02/12/2023] Open
Abstract
As a result of their rapid development, polymer composites are seeing wider use in transportation infrastructure in China and worldwide [...].
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Affiliation(s)
- Wensheng Wang
- College of Transportation, Jilin University, Changchun 130022, China
- Correspondence:
| | - Yongchun Cheng
- College of Transportation, Jilin University, Changchun 130022, China
| | - Heping Chen
- Ingram School of Engineering, Texas State University, San Marcos, TX 78666, USA
| | - Guojin Tan
- College of Transportation, Jilin University, Changchun 130022, China
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Du Y, He X, Wu C, Wu W. Long-term monitoring and analysis of the longitudinal differential settlement of an expressway bridge-subgrade transition section in a loess area. Sci Rep 2022; 12:19327. [PMID: 36369340 PMCID: PMC9652310 DOI: 10.1038/s41598-022-23829-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022] Open
Abstract
To solve the problem of "bridgehead bumping" in the transition section between the road and bridge of an expressway in a collapsible loess area, a lime-soil compaction pile composite foundation is used for the first time in the transition section between the road and bridge of an expressway in China; the loess subgrade is improved by adding lime, and the subgrade is arranged in a multilayer geogrid for the joint treatment of various engineering measures. At the same time, a new type of precision differential pressure settlement meter is used to monitor the long-term settlement of a bridge-subgrade transition section with a small settlement magnitude after the joint treatment, and the distribution characteristics and variation laws of the settlement along the longitudinal direction of the line are obtained. The results show that the effect is better and the differential settlement is smaller when using a lime-soil compaction pile composite foundation; lime improves the loess subgrade backfill, and the multilayer geogrid addresses the bridge-subgrade transition in the collapsible loess area. The differential settlement and settlement rate of the subgrade and abutment increase with increased monitoring time, and the differential settlement increases gradually, while the growth rate decreases gradually and finally tends to be stable. The differential settlement of the transition section is predicted and analysed by using a hyperbolic curve, exponential curve and their combination in a prediction model, and the prediction analysis shows that the combined prediction model has the best prediction effect. These research results can provide guidance and reference for the design and construction of subgrade structures similar to the wet transition section between roads and bridges.
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Affiliation(s)
- Yang Du
- grid.162110.50000 0000 9291 3229School of Transportation and Logistics Engineering, Wuhan University of Technology, Wuhan, 430063 China ,grid.495869.f0000 0004 8343 6714Wuhan Municipal Engineering Design & Research Institute Co., Ltd, Wuhan, 430023 China
| | - Xiongjun He
- grid.162110.50000 0000 9291 3229School of Transportation and Logistics Engineering, Wuhan University of Technology, Wuhan, 430063 China
| | - Chao Wu
- grid.162110.50000 0000 9291 3229School of Transportation and Logistics Engineering, Wuhan University of Technology, Wuhan, 430063 China
| | - Weiwei Wu
- grid.162110.50000 0000 9291 3229School of Transportation and Logistics Engineering, Wuhan University of Technology, Wuhan, 430063 China
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