کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4743887 1641843 2012 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Swelling pressures of compacted Ca-bentonite
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات مهندسی ژئوتکنیک و زمین شناسی مهندسی
پیش نمایش صفحه اول مقاله
Swelling pressures of compacted Ca-bentonite
چکیده انگلیسی

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/m3. 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.


► Swelling pressures were measured to investigate the swelling behavior of Ca-bentonite.
► The effects of dry density and salinity on the swelling pressures were investigated.
► The swelling mechanism for the Ca-bentonite in NaCl solutions was different from that for Na-bentonite.
► The swelling mechanism was conceptualized and explained based upon experimental results.
► The obtained results suggest an engineering significance in the design of a HLW repository.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Engineering Geology - Volumes 129–130, 19 March 2012, Pages 20–26
نویسندگان
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