Abstract
The impact of natural sodium bentonite on the microstructure, permeability and strength characteristics of bentonite-modified loess (BML) were evaluated by scanning electron microscope (SEM) test, triaxial flexible wall permeability test, uniaxial compression test and direct shear tests. The experimental results indicate that bentonite can be used for loess solidification attributed to its effective particle filling, water absorption and expansion characteristics. The quantitative parameters of SEM images such as the average pore area, width, length and surface porosity of BML declined first and then increased with bentonite content, and the lowest was observed at a bentonite content of 15%. The hydraulic conductivity of BML declined with increasing bentonite content and was lower than the maximum allowable limit of 1.0 × 10−9 m/s. The uniaxial compressive strength and shear strength parameters of BML increased initially and subsequently declined as bentonite content increased. A normalized prediction model was established for modified loess based on the correlation between mechanical characteristics and the microscopic pore parameters, which was verified to be rational in estimating the macro- and micro-scale properties of BML. Therefore, when the anti-seepage landfill layers are constructed in the Loess Plateau area, 15% of bentonite is recommended in modified loess, which has optimal impermeability and mechanical properties.
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References
ASTM D2487-17e1 (2017) Standard practice for classification of soils for engineering purposes (Unified Soil Classification System), ASTM International, West Conshohocken, PA, DOI: https://doi.org/10.1520/D2487-17E01
ASTM D5084-16a (2016) Standard test methods for measurement of hydraulic conductivity of saturated porous materials using a flexible wall permeameter, ASTM International, West Conshohocken, PA, DOI: https://doi.org/10.1520/D5084-16A
Chen HE, Jiang YL, Niu CC, Leng GJ, Tian GL (2019) Dynamic characteristics of saturated loess under different confining pressures: A microscopic analysis. Bulletin of Engineering Geology and the Environment 78(2):931–944, DOI: https://doi.org/10.1007/s10064-017-1101-9
Chen WW, Jia QQ, Liu P, Tong YM (2021) Determining the unsaturated hydraulic conductivity of remoulded loess with filter paper method and soil column seepage test. Environmental Earth Sciences 80(24):808, DOI: https://doi.org/10.1007/s12665-021-10100-2
Cheng G, Zhu HH, Wen YN, Shi B, Gao L (2020) Experimental investigation of consolidation properties of nano-bentonite mixed clayey soil. Sustainability 12(2):459, DOI: https://doi.org/10.3390/su12020459
Du YJ, Fan RD, Liu SY, Reddy KR, Jin F (2015) Workability, compressibility and hydraulic conductivity of zeolite-amended clayey soil/calcium-bentonite backfills for slurry-trench cutoff walls. Engineering Geology 195:258–268, DOI: https://doi.org/10.1016/j.enggeo.2015.06.020
Falamaki A, Eskandari M, Homaee M, Gerashi M (2018) An improved multilayer compacted clay liner by adding bentonite and phosphate compound to sandy soil. KSCE Journal of Civil Engineering 22(10):3852–3859, DOI: https://doi.org/10.1007/s12205-018-1554-9
Fan RD, Du YJ, Reddy KR, Liu SY, Yang YL (2014) Compressibility and hydraulic conductivity of clayey soil mixed with calcium bentonite for slurry wall backfill: Initial assessment. Applied Clay Science 101:119–127, DOI: https://doi.org/10.1016/j.clay.2014.07.026
GB/T 50123-2019 (2019) China national standards: Standard for geotechnical testing method. Standardization Administration of China, Ministry of Water Resources, China Planning Press, Beijing, China (in Chinese)
GB/T 51403-2021 (2021) China national standards: Technical standard for liner system of municipal solid waste sanitary landfill. Standardization Administration of China, Ministry of Housing and Urban-Rural Development of the People’s Republic of China, China Planning Press, Beijing, China (in Chinese)
Gibbs HJ, Holland WY (1960) Petrographic and engineering properties of loess. Engineering Monograph, US Bureau of Reclamation, Colorado, USA 12–13
He J, Wang Y, Li Y, Ruan XC (2015) Effects of leachate infiltration and desiccation cracks on hydraulic conductivity of compacted clay. Water Science and Engineering 8(2):151–157, DOI: https://doi.org/10.1016/j.wse.2015.04.004
Jadda K, Bag R (2020) Variation of swelling pressure, consolidation characteristics and hydraulic conductivity of two Indian bentonites due to electrolyte concentration. Engineering Geology 272:105637, DOI: https://doi.org/10.1016/j.enggeo.2020.105637
Jin GL, Xu HQ, Zhou AZ, Jiang PM (2021) Permeability of soil-bentonite cut-off wall backfill material. Materials Letters 305:130775, DOI: https://doi.org/10.1016/j.matlet.2021.130775
Jing X, Cui ZZ, Doh S, Ma L, Wei L, Liu D (2021) Effect of freeze-thaw cycles on shear strength of unsaturated bentonite modified clay. Physics and Chemistry of the Earth 121:102955, DOI: https://doi.org/10.1016/j.pce.2020.102955
Li X, Lu YD, Zhang XZ, Fan W, Lu YC, Pan WS (2019) Quantification of macropores of Malan loess and the hydraulic significance on slope stability by X-ray computed tomography. Environmental Earth Sciences 78(16):522, DOI: https://doi.org/10.1007/s12665-019-8527-2
Liu JY, Li XA, Xue Q, Guo ZZ (2020a) Experimental study on air permeability and microscopic mechanism of intact and remolded Malan loess, Loess Plateau, China. Bulletin of Engineering Geology and the Environment 79(8):3909–3919, DOI: https://doi.org/10.1007/s10064-020-01810-1
Liu Z, Liu FY, Ma FL, Wang M, Bai XH, Zheng YL, Yin H, Zhang GP (2016) Collapsibility, composition, and microstructure of loess in China. Canadian Geotechnical Journal 53(4):673–686, DOI: https://doi.org/10.1139/cgj-2015-0285
Liu C, Shi B, Zhou J, Tang CS (2011) Quantification and characterization of microporosity by image processing, geometric measurement and statistical methods: Application on SEM images of clay materials. Applied Clay Science 54(1):97–106, DOI: https://doi.org/10.1016/j.clay.2011.07.022
Liu JF, Song SB, Cao XL, Meng QB, Pu H, Wang YG, Liu JF (2020b) Determination of full-scale pore size distribution of Gaomiaozi bentonite and its permeability prediction. Journal of Rock Mechanics and Geotechnical Engineering 12(2):403–413, DOI: https://doi.org/10.1016/j.jrmge.2019.12.005
Liu C, Tang CS, Shi B, Suo WB (2013) Automatic quantification of crack patterns by image processing. Computers & Geosciences 57:77–80, DOI: https://doi.org/10.1016/j.cageo.2013.04.008
Ma GL, He X, Jiang X, Liu HL, Chu J, Xiao Y (2021) Strength and permeability of bentonite-assisted biocemented coarse sand. Canadian Geotechnical Journal 58(7):969–981, DOI: https://doi.org/10.1139/cgj-2020-0045
Mishra AK, Ohtsubo M, Li L, Higashi T (2011) Controlling factors of the swelling of various bentonites and their correlations with the hydraulic conductivity of soil-bentonite mixtures. Applied Clay Science 52(1):78–84, DOI: https://doi.org/10.1016/j.clay.2011.01.033
Mu QY, Zhou C, Ng CWW (2020) Compression and wetting induced volumetric behavior of loess: Macro- and micro-investigations. Transportation Geotechnics 23:100345, DOI: https://doi.org/10.1016/j.trgeo.2020.100345
Naeini SA, Gholampoor N, Jahanfar MA (2019) Effect of leachate’s components on undrained shear strength of clay-bentonite liners. European Journal of Environmental and Civil Engineering 23(3):395–408, DOI: https://doi.org/10.1080/19648189.2017.1278725
Niu ZL, Xu J, Li YF, Wang ZF, Wang B (2022) Strength deterioration mechanism of bentonite modified loess after wetting-drying cycles. Scientific Reports 12(1):3130, DOI: https://doi.org/10.1038/s41598-022-06962-6
Parastar F, Hejazi SM, Sheikhzadeh M, Alirezazadeh A (2017) A parametric study on hydraulic conductivity and self-healing properties of geotextile clay liners used in landfills. Journal of Environmental Management 202:29–37, DOI: https://doi.org/10.1016/j.jenvman.2017.07.013
Pokharel B, Siddiqua S (2021) Effect of calcium bentonite clay and fly ash on the stabilization of organic soil from Alberta, Canada. Engineering Geology 293:106291, DOI: https://doi.org/10.1016/j.enggeo.2021.106291
Qasaimeh A, Sharo AA, Bani-Melhem K (2020) Clayey soil amendment by hydrophilic nano bentonite for landfill cover barrier: a case study. Journal of Environmental Engineering and Landscape Management 28(3):148–156, DOI: https://doi.org/10.3846/jeelm.2020.12715
Qie YY, Zhang P, Cui ZZ, Hu Y Ma XB (2017) The strength characteristics of loess modified with bentonite. Journal of Agricultural University of Hebei 40(6):125–128, DOI: https://doi.org/10.13320/j.cnki.jauh.2017.0138 (in Chinese)
Rahmani A, Hazzab A, Aimer H, Ghenaim A, Terfous A (2020) Improvement of physical-chemical and rheological properties of Ghardaïa loess (southern Algeria) using bentonite clay and lime. Clays and Clay Minerals 68(5):499–512, DOI: https://doi.org/10.1007/s42860-020-00092-8
Rout S, Singh SP (2020) Characterization of pond ash-bentonite mixes as landfill liner material. Waste Management and Research 38(12): 1420–1428, DOI: https://doi.org/10.1177/0734242X20918013
Sun WJ, Xu G Wei G, Zhang WJ, Sun DA (2021) Effects of ammonium ion and bentonite content on permeability of bentonite-clay mixture. Environmental Earth Sciences 80(4):151, DOI: https://doi.org/10.1007/s12665-021-09440-w
Wang HK, Qian H, Gao YY (2021) Characterization of macropore structure of remolded loess and analysis of hydraulic conductivity anisotropy using X-ray computed tomography technology. Environmental Earth Sciences 80(5):197, DOI: https://doi.org/10.1007/s12665-021-09405-z
Wei YN, Fan W, Yu B, Deng LS, Wei TT (2020) Characterization and evolution of three-dimensional microstructure of Malan loess. CATENA 192:104585, DOI: https://doi.org/10.1016/j.catena.2020.104585
Wu JW, Xie HJ, Zhang CH, Bouazza A, Sun ZL, Qiu ZH (2022) Adsorption behavior of bisphenol A on bentonite-loess mixtures. Environmental Science and Pollution Research 29(4):6360–6374, DOI: https://doi.org/10.1007/s11356-021-15888-x
Xu PP, Zhang QY Qian H, Hou K (2020a) Investigation into microscopic mechanisms of anisotropic saturated permeability of undisturbed Q2 loess. Environmental Earth Sciences 79(18):412, DOI: https://doi.org/10.1007/s12665-020-09152-7
Xu PP, Zhang QY, Qian H, Qu WG (2020b) Effect of sodium chloride concentration on saturated permeability of remolded Loess. Minerals 10(2):199, DOI: https://doi.org/10.3390/min10020199
Yan XQ, Fang YG, Zhang P (2011) Experiment study on the effects of bentonite on the micropore structure characteristics of soil. Chinese Journal of Geotechnical Engineering 33(8):1302–1307 (in Chinese)
Yang B, Zhang HY, Zhao TY, Liu JS, Chen H (2011) Responsibility of permeability of modified loess soil on microstructure. Hydrogeology and Engineering Geology 38(6):96–101, DOI: https://doi.org/10.16030/j.cnki.issn.1000-3665.2011.06.024 (in Chinese)
Zhang M, Chen GZ, Liu Y, Huang SH (2021) Experimental study on the mechanical property of loess mixed with bentonite-HDTMA. Advances in Materials Science and Engineering 2021:1–9, DOI: https://doi.org/10.1155/2021/7623682
Zhang WP, Sun YF, Chen WW, Song YP, Zhang JK (2019) Collapsibility, composition, and microfabric of the coastal zone loess around the Bohai Sea, China. Engineering Geology 257:105142, DOI: https://doi.org/10.1016/j.enggeo.2019.05.019
Zhang HY, Zhao TY, Wu JR, Yan GS, Feng L (2011) Laboratory measurement and prediction to the permeability of bentonite-modified loess as a landfill liner. Rock and Soil Mechanics 32(7): 1963–1969,1974, DOI: https://doi.org/10.16285/j.rsm.2011.07.007 (in Chinese)
Zhao TY, Zhang HY, Yan GS, Wu JR, Liu JS (2010) Influence of penetrative conditions on permeability of modified loess soil by bentonite. Hydrogeology and Engineering Geology 37(5):108 (in Chinese)
Zhou J, Xu J, Yu LG, Luo LH (2019) Microscopic mechanism regarding permeability anisotropy of kaolin-montmorillonite mixed clays. Chinese Journal of Geotechnical Engineering 41(6):1005–1013, DOI: https://doi.org/10.11779/CJGE201906003 (in Chinese)
Zou WL, Ding LQ, Han Z, Wang XQ (2020) Effects of freeze-thaw cycles on the moisture sensitivity of a compacted clay. Engineering Geology 278:105832, DOI: https://doi.org/10.1016/j.enggeo.2020.105832
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This work was supported by the National Natural Science Foundation of China (Grant No. 51878551). This financial support is gratefully acknowledged.
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Li, Y., Xu, J., Wang, Z. et al. Experimental Study on Microstructure and Hydraulic Performance of Bentonite Modified Loess. KSCE J Civ Eng 27, 2778–2791 (2023). https://doi.org/10.1007/s12205-023-0868-4
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DOI: https://doi.org/10.1007/s12205-023-0868-4