Modelling Concrete Degradation by Coupled Non-linear Processes

Concrete in a transuranic (TRU) waste repository is considered a suitable material to ensure safety, provide structural integrity and retard radionuclide migration after the waste containers fail. Modelling of concrete degradation often focuses solely on solid-water chemical reactions and related changes in porosity, however, cracking and damage from steel corrosion will likely exert significant control over the mass-transport properties of concrete. In the current study, coupling between chemical, mass-transport and mechanical, so-called non-linear processes that control concrete degradation and crack development were investigated by coupled numerical models. Application of such coupled numerical models allows identification of the dominant non-linear processes that will control long-term concrete degradation and crack development in a TRU waste repository.