COLLABORATIVE CONTROL OF WORKABILITY FOR LOESS MIXED WITH BENTONITE-HDTMA
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摘要: 选取河南三门峡地区马兰黄土,掺加不同比例的膨润土与十六烷基三甲基溴化铵(HDTMA),开展界限含水率和标准击实试验,探讨膨润土-HDTMA对垃圾填埋场黄土衬里材料可施工性能的调控机理。研究表明:当膨润土的质量掺量超过10%时,黄土物理指标由粉土类过渡为黏土类;掺入质量掺量小于4%的HDTMA,有助于改善黄土的物理性质;此外,膨润土与HDTMA能够缓冲盐分对黄土衬里材料物理性质的消极影响。随着膨润土增加,改性黄土最大干密度和最优含水率分别增大和减小;HDTMA的掺入加剧了黄土最大干密度的减小趋势,但对最优含水率影响有限。从微观角度,HDTMA的掺入,改变了黏土颗粒层间结构;膨润土的掺入,导致包裹粗颗粒的黏土细颗粒占据了更多的空间。据此,建立了膨润土改性黄土最大干密度与最优含水率的线性函数关系。从可施工性角度而言,黄土作为垃圾填埋场衬里材料,膨润土掺量需不小于10%,HDTMA掺量建议不超过2%。Abstract: The tests for the limit moisture content and compaction on Malan loess from Sanmenxia in Henan mixed with different proportions of bentonite and HDTMA were conducted to explore the effect mechanism of bentonite and HDTMA on the workability of loess liners in landfills. The plasticity index of loess increased from silt to clay when the mass content of bentonite was more than 10%, and to mix HDTMA with a mass content less than 4% could optimize the physical properties of loess. Besides, both of the bentonite and HDTMA could buffer the negative effects of salts on physical properties of loess. The maximum dry density and optimal moisture content of the loess would respectively be increased and reduced with the increase of the bentonite content. The addition of HDTMA was benefit to reduce the maximum dry density of loess, but had a little influence on the optimal moisture content. In the microstructure, the HDTMA changed the structure of clay particles; the increase of bentonite made clay particles of being adhered to coarse particles occupy more spaces. Based on the data by tests,a linear function relation between the maximum dry density and the optimal moisture content for the modified loess was proposed. From the perspective of workability, the proportion of bentonite should be more than 10% and the proportion of HDTMA should be less than 2% in loess for liners of landfills.
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Key words:
- loess /
- bentonite-HDTMA /
- limit moisture content test /
- compaction test /
- workability
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[1] RUNGROJ A K S, POTPREECHA P M E. Assessment of Geological, Hydrogeological and Geotechnical Characteristics of a Proposed Waste Disposal Site:A Case Study in Khon Kaen, Thailand[J/OL]. Geosciences, 2020, 10(3). DOI: 10.3390/geosciences10030109. [2] 钱琪所, 孔慈明, 孔繁亮. 渗滤液腐蚀黏土衬垫的力学特性及孔隙变化[J]. 环境科学与技术, 2020, 43(1):201-206. [3] 张虎元, 赵天宇, 吴军荣, 等. 膨润土改性黄土衬里防渗性能室内测试与预测[J]. 岩土力学, 2011, 32(7):1963-1969,1974. [4] LIU Y S, BAI Q Z, NIE Y F. Properties of Bentonite Enhanced Loess and Laterite[J]. Chinese Journal of Chemical Engineering, 2004(1):43-47. [5] 郄玥颖. 膨润土改性宁夏黄土的性能[D]. 银川:宁夏大学, 2018. [6] XU H Q, SHU S, WANG S W, et al. Studies on the Chemical Compatibility of Soil-Bentonite Cut-Off Walls for Landfills[J]. Journal of Environmental Management, 2019, 237:155-162. [7] XU S F, BIAN M D, LI C F, et al. Effects of Calcium Concentration and Differential Settlement on Permeability Characteristics of Bentonite-Sand Mixtures[J]. Applied Clay Science, 2018, 153:16-22. [8] 董军, 赵勇胜, 蒋惠忠. 改性黏土防渗层性能研究及影响因素分析[J]. 环境工程, 2005, 23(1):87-91. [9] KOLSTAD D C, BENSON C H, EDIL T B. Hydraulic Conductivity and Swell of Nonrehydrated Geosynthetic Clay Liners Permeated with Multispecies Inorganic Solutions[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2004, 130(12):1236-1249. [10] IRENE M C, LO R K M, SAMUEL, et al. Modified Clays for Waste Containment and Pollutant Attenuation[J]. Journal of Environmental Engineering, 1997, 123(1):25-32. [11] AGNIESZKA G P, MAREK M, STANISŁAW P, et al. Simultaneous Adsorption of Chromium (VI) and Phenol on Natural Red Clay Modified by HDTMA[J]. Chemical Engineering Journal, 2012, 179:140-150. [12] CHEN S P, QI Y S, JORDAO J C, et al. Efficient Removal of Radioactive Iodide Anions from Simulated Wastewater by HDTMA-Geopolymer[J]. Progress in Nuclear Energy, 2019, 117:103112. [13] 中华人民共和国住房和城乡建设部.土工试验方法标准:GB/T 50123-2019[S].北京:中国建筑工业出版社,2019. [14] 中华人民共和国住房和城乡建设部.生活垃圾卫生填埋处理技术规范:GB 50869-2013[S]. 北京:中国建筑工业出版社,2013. [15] PENG Y, LI Y, PENG Q. Method for Raising Accuracy of Limit Moisture Content in Combined Measurement of Liquid and Plastic Limits[J]. Soil Engineering and Foundation, 2007, 21(4):81-84. [16] Zhang H Y,CUI S L, ZHANG M, et al. Swelling Behaviors of GMZ Bentonite-Sand Mixtures Inundated in NaCl-Na2SO4 Solutions[J]. Nuclear Engineering and Design, 2012, 242:115-123. [17] YU X F. The Preparation and Characterization of Cetyltrimethyla-mmonium Intercalated Muscovite[J]. Microporous & Mesoporous Materials, 2007, 98(1/2/3):70-79. [18] 赵天宇, 吴军荣, 张虎元. 粉煤灰堆场膨润土改性黄土衬里的击实性能研究[J]. 粉煤灰, 2010(2):28-32. [19] 黄英, 符必昌. 确定土的最大干密度和最优含水率的数解法[J]. 岩土工程学报, 2002, 24(4):538-540.
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