Concrete perturbation in a 13-year in situ concrete/bentonite interaction from FEBEX experiments. New insight of 2:1 Mg phyllosilicate precipitation at the interface

The Engineered Barrier System (EBS) implemented in full-scale experiments are designed to provide an understanding of the long-term performance of Deep Geological Repositories (DGR) as nuclear waste repositories. The existing interfaces between the engineered barrier materials, such as concrete and bentonite, constitute reactive surfaces on which the thickness and intensity of degradation of the material, which may affect the confinement properties, are under investigation. This study focuses on a concrete projected on a saturated compacted bentonite from the in situ FEBEX experiment, emplaced in the Grimsel Test Site (GTS, Switzerland) and dismantled during 2015 after 13 years of functioning.