Thermodynamic Response of Crystalline Swelling and Double-Layer Swelling of Compacted Bentonite
Strong thermodynamic disequilibrium existed in HLW repository site often deteriorates the hydration swelling capacity of compacted bentonite, including the crystalline swelling and the double-layer swelling. In order to investigate the temperature effect on the crystalline swelling capacity and the double-layer swelling capacity, four swelling pressure tests and four swelling strain tests were conducted on compacted Gaomiaozi (GMZ) bentonite specimens saturated with de-ionized water under the temperature of 20 °C to 80 °C. Main observations show that the crystalline swelling capacity and the double-layer swelling capacity generally decrease with the temperature increases; whereas the crystalline swelling pressure and the double-layer swelling strain present a slight increase tendency under higher temperatures, especially the temperature 60 °C and 80 °C.
KeywordsCompacted bentonite Crystalline swelling Double-layer swelling Swelling pressure Swelling strain
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