环境参数对冻融循环后GCL材料中膨润土膨胀指数的影响

发布时间：2018-01-08 01:20

本文关键词：环境参数对冻融循环后GCL材料中膨润土膨胀指数的影响　出处：《东南大学学报(自然科学版)》2016年S1期 　论文类型：期刊论文

【摘要】：为了解不同环境参数对经一定次数冻融循环后GCL材料中膨润土膨胀性的影响,通过室内试验研究了不同温度、盐浓度、pH值条件下,经10,20和40次冻融循环后GCL材料中膨润土膨胀指数的变化规律及颗粒粒径分布.结果表明,在相同冻融循环次数下,膨胀指数随温度的升高而增大,最大增幅为30.77%;随盐浓度和溶液酸碱度的增大而减小,最大减幅分别为65.22%和15.38%.在相同盐浓度或pH值条件下,膨胀指数与冻融循环次数无明显关系,而在相同水浴温度下,膨胀指数与冻融循环次数呈明显正相关.激光粒度仪试验结果表明,环境参数会对GCL材料中膨润土的颗粒粒径分布产生显著影响,继而影响试样的膨胀指数.
[Abstract]:In order to understand the effect of different environmental parameters on the swelling properties of bentonite in GCL materials after a certain number of freeze-thaw cycles, the effects of different temperature, salt concentration and pH value on the expansion of bentonite were studied in laboratory. The change rule of bentonite expansion index and particle size distribution in GCL materials after 20 and 40 freeze-thaw cycles. The results show that the expansion index increases with the increase of temperature under the same freezing and thawing cycles. The largest increase was 30.77; With the increase of salt concentration and pH of the solution, the maximum decreases are 65.22% and 15.38 respectively. Under the same salt concentration or pH value, the expansion index has no obvious relationship with the number of freeze-thaw cycles. However, at the same water bath temperature, the expansion index was positively correlated with the number of freeze-thaw cycles. The results of laser granulometer showed that the environmental parameters had a significant effect on the particle size distribution of bentonite in GCL materials. Then the expansion index of the sample is affected.
【作者单位】：东南大学岩土工程研究所;东南大学江苏省城市地下工程与环境安全重点实验室;
【基金】：国家自然科学基金资助项目(41272311,41330641,41672280)
【分类号】：TU443
【正文快照】： 土工织物膨润土垫(GCL)由于其优越的防渗性,在水利、岩土、环境等工程领域得到了广泛应用.同时,GCL材料的膨胀性又很大程度上决定了其防渗性能,因此对其膨胀性的研究对了解其防渗机理有重要意义.陈宝等[1]对不同初始干密度的膨润土试样在3种浓度的Na OH溶液环境下分别开展渗透

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