Interaction processes at the concrete-bentonite interface after 13 years of FEBEX-Plug operation. Part II: Bentonite contact

摘要

The in situ FEBEX experiment performed at the URL in Grimsel (Swizerland) was dismantled after 18 years of operation. Interface samples between bentonite and a shotcreted concrete plug that was constructed in a second operational phase have been studied after 13 years of interaction. Mineralogical and geochemical characterization of samples have been performed by XRD, SEM-EDX, TG and FTIR techniques in addition to determinations of major ions by chemical analysis of aqueous extracts, delta O-18 and delta C-13 stable isotopes both in concrete paste and bentonite, and exchangeable cations in bentonite.