Effects of K+ solutions on swelling behavior of compacted GMZ bentonite
Effects of K+ solutions on swelling behavior of compacted GMZ bentonite
复制标题
K溶液对压实GMZ膨润土膨胀行为的影响
DOI：
10.1016/j.enggeo.2018.12.020
复制
发表时间：
2019-01-31
影响因子：
7.4
通讯作者：
Cui, Yu-Jun
中科院分区：
文献类型：
--
作者：
He, Yong;Ye, Wei-Min;Cui, Yu-Jun
在深层地质储存库的长期运行过程中，压实膨润土的缓冲/回填性能会受到渗入孔隙水化学成分的影响。在本研究中，对初始干密度为1.5或1.7 mg/m(3)的GMZ膨润土在蒸馏水渗透以及KCI和KOH溶液(0.1和1.0M)中进行了膨胀试验和微观结构分析。研究了K+溶液对压实GMZ膨润土膨胀行为的影响。结果表明，K+溶液浓度和样品干密度对压实GMZ膨润土的溶胀性能有显著影响。K盐/碱溶液的渗透显著降低了压实GMZ膨润土的膨胀压力。在渗透KCI或KOH溶液的膨胀应变试验中，观察到的是体积坍塌阶段，而不是二次膨胀阶段。微观结构测试结果表明，膨胀性的减弱可以归因于K+交换或二氧化硅溶解。
During the long-term operation of a deep geological repository, the buffer/backfill properties of compacted bentonite could be affected by the chemistry of the infiltrated porewater. In this study, swelling tests and microstructural analyses were conducted on the compacted GMZ bentonite specimens with an initial dry density of 1.5 or 1.7 Mg/m(3) with infiltration of distilled water, as well as, KCI and KOH solutions (0.1 and 1.0 M). Influences of K+ solutions on the swelling behavior of compacted GMZ bentonite were investigated. Results show that swelling properties of compacted GMZ bentonite specimens could be significantly influenced by concentration of K+ solutions and dry density of specimens. Swelling pressure of compacted GMZ bentonite specimens was significantly attenuated by infiltration of K salt/alkaline solutions. For swelling strain tests with infiltration of KCI or KOH solutions, instead of a secondary swelling stage, a volumetric collapse stage was observed. Micro-structural test results demonstrate that the attenuation of swelling behavior could be attributed to the K+ exchange or silica dissolution.