Nearfield behaviour of clay barriers and their interaction with concrete
In order to guarantee the safety of underground waste disposal, engineered barriers will be implemented as backfill materials in galleries and access shafts and as buffer materials between the host medium and the waste packages. One of the first requirements for engineered barriers is to minimise water and chemical species transfer. The materials being considered are essentially swelling clays, in particular calcium smectite clays from French deposits and hydraulic binders, and, especially, a ternary cement named CLC. Vitrified waste disposal in granite is taken as the most constraining scenario as far as an engineered barrier is concerned. The clay buffer material is placed between the packages and the host rock. The main properties which are determined are directly related to the engineered barrier requirements i.e. thermal conductivity, hydraulic conductivity, swelling pressure and swelling capacity. Moreover, results are obtained for the effect of temperature on clay microstructure and properties in both cases - with and without water intake. The concrete durability with regard to clay-pore water attack is evaluated in order to ensure LLW disposal safety.
Bibliographic Reference: EUR 13877 EN (1991) 63 pp., FS, ECU 6.25
ISBN: ISBN 92-826-3312-8
Record Number: 199210021 / Last updated on: 1994-12-02
Original language: en
Available languages: en