Accumulated Vertical Strain Without Confining Pressure for Compacted Bentonite Due to Hydration Effort
To use high dense compacted bentonite or bentonite-sand mixture material are accepted as engineered barriers for high level nuclear waste disposal waste. The bentonite as engineered barrier is initially in unsaturated condition before pore water coming from natural host rock. The bentonite subjected to thermo-hydro-mechanical actions by natural geological situation and the canisters of high-level radioactive disposal waste. This study conducted out the creep test for compacted bentonite, and the developed relative humidity circulation triaxial apparatus. Two different initial water contents were prepared to make the specimens at constant dry density. As parameter for this creep test, the stress ratio was defined using specified unconfined compressive strength. All specimens were applied without confining pressure. The vapor transfers due to changing of relative humidity induced some hydration efforts that were controlled using vapor pressure technique. Performing the creep test in this study is of couple hydro-mechanical and is applied to identification for two efforts (i.e. strain due to hydration and stain by deviator compression stress). Investigation of creep behavior that accumulated strains associated to couple thermo-mechanical actions are measured at constant deviator compression stress.
KeywordsBentonite Creep test Suction
- Alonso EE, Romero E, Hoffmann C, Garcıa-Escudero E (2005) Expansive bentonite–sand mixtures in cyclic controlled-suction drying and wetting. Eng GeolGoogle Scholar
- Nishimura T, Koseki J (2013) Influence of shear speed on direct shear strength for compacted bentonite with different soil suctions. In: Third international conference on geotechnique, construction materials and environment, Nagoya, Geo-Mate 2013, pp 598–603 (2013)Google Scholar
- Nishimura T, Koseki J (2014) Deformation of compacted bentonite due to changes in relative humidity. In: Proceedings of the sixth international conference on unsaturated soils, UNSAT2014, pp 923–928 (2014)Google Scholar