Swelling pressures of compacted Ca-bentonite
Swelling pressures of compacted Ca-bentonite
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DOI：
10.1016/j.enggeo.2012.01.005
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发表时间：
2012-03-19
影响因子：
7.4
通讯作者：
Kwon, Sangki
中科院分区：
文献类型：
--
作者：
Lee, Jae Owan;Lim, Jin Gyu;Kwon, Sangki
高放废物处置库膨润土缓冲层的主要功能之一是通过其与自由水接触时膨胀的能力提供具有自密封能力的缓冲层。通过膨胀压测量来研究钙基膨润土的膨胀行为。实验结果表明，膨胀压力随干密度的增加而增加，当干密度大于1.6 Mg/m3时，膨胀压力对干密度的依赖性增大。矿化度对钙基膨润土和钠基膨润土膨胀压力的影响不同。与软化水相比，钙基膨润土在稀释浓度的NaCl溶液（0.04 M）中的膨胀压力较高，然后随着NaCl溶液浓度的增加而降低，超过0.04 M。钙基膨润土的这种膨胀行为是由溶液中的Ca 2+与Na+的离子交换，然后与水分子水合和由于NaCl溶液浓度的差异而引起的渗透来解释的。(C)2012爱思唯尔有限公司版权所有。
One of the major functions of a bentonite buffer for a HLW repository is to provide the buffer with a self-sealing capacity through its ability to swell on contact with free water. Swelling pressure measurements were carried out to investigate the swelling behavior of Ca-bentonite. Experimental results showed that the swelling pressure increased with an increase in dry density, and its dependence on dry density increased at higher dry densities beyond 1.6 Mg/m(3). The effect of salinity on the swelling pressure for the Ca-bentonite was different from that for Na-bentonite. The swelling pressure of the Ca-bentonite was higher in a diluted concentration of NaCl solution (0.04 M) compared with de-mineralized water, and it then decreased with an increase in the concentration of the NaCl solution beyond 0.04 M. Such a swelling behavior of the Ca-bentonite was explained by the ion-exchange of Ca2+ for Na+ from the solution followed by hydration with water molecules and osmosis due to the differences in concentrations of the NaCl solutions. (C) 2012 Elsevier B.V. All rights reserved.