复杂环境条件下改性膨润土的抗盐性能  

Salt resistance of modified bentonite in complex environment

作　　者：杨微 任孟健[1,2,3] 陈仁朋 刘雪莹 康馨[1,2,3] YANG Wei;REN Meng-jian;CHEN Ren-peng;LIU Xue-ying;KANG Xin(Key Laboratory of Building Safety and Energy Efficiency of Ministry of Education,Hunan University,Changsha 410082,China;National Center for International Research Collaboration in Building Safety and Environment,Hunan University,Changsha 410082,China;College of Civil Engineering,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学建筑安全与节能教育部重点实验室,湖南长沙410082 [2]湖南大学建筑安全与环境国际联合研究中心,湖南长沙410082 [3]湖南大学土木工程学院,湖南长沙410082

出　　处：《浙江大学学报（工学版）》2021年第10期1885-1893,共9页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(52078207,51938005);国家自然科学基金青年科学基金资助项目(41807261);湖南省科技计划资助项目(2019RS1030).

摘　　要：为了增强膨润土防水毯(GCL)的抗盐性,使用聚丙烯酸钠对膨润土进行改性,采用扫描电镜(SEM)、傅里叶变换红外光谱(FTIR)、Zeta电位和自动比表面及孔隙度分析仪(BET),分析材料的微观结构及特性.结果表明,膨润土颗粒与聚合物发生了良好的结合作用,改性膨润土表面出现新的亲水官能团,土颗粒分散更均匀,片层结构更清晰.在改性剂作用下原有小孔隙被包裹和填充,改性土比表面积减小,平均孔径增大.改性土在不同pH、阳离子类型和不同浓度盐溶液作用下的自由膨胀试验结果表明,改性土的膨胀性能提升显著.渗透试验结果显示,改性土水中渗透系数由原土的10^(−8) m/s减少至10^(−9) m/s数量级,且在同浓度盐溶液中抗渗性能有明显增强.The bentonite was modified with sodium polyacrylate,and the microstructure characteristics of the material were analyzed by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR),Zeta potential and BET in order to enhance the salt resistance of geosynthetic clay liner(GCL).Results show that the bentonite particles have a good combination with the polymer,and new hydrophilic functional groups appear on the surface of the modified bentonite.The dispersion of the modified bentonite is more uniform,and the lamella structure is clearer.The specific surface area of the modified soil decreases and the average pore diameter increases as the small pores are wrapped and filled by the modifier.The swelling properties of the modified bentonite with different pH,cation types and cation concentrations showed that the swelling performance of modified bentonite was significantly improved.The results of the permeability test showed that the permeability coefficient of the modified soil was reduced from 10^(−8) m/s of the bentonite to the order of 10^(−9) m/s,and the impermeability of the modified soil was significantly enhanced in the same concentration of salt solution.

关 键 词：改性膨润土 抗盐性 膨润土防水毯(GCL) 膨胀性 渗透性 

分 类 号：TU411[建筑科学—岩土工程]