Modelling Concrete Degradation by Couple

Concrete in a transuranic (TRU) waste repository is regarded as a vital material for ensuring safety, maintaining structural integrity, and hindering the migration of radionuclides after the failure of waste containers. Traditional modeling of concrete degradation has predominantly focused on solid-water chemical reactions and changes in porosity; however, this study highlights the significant impact of cracking and steel corrosion on the mass-transport properties of concrete. The objective of this research was to investigate the coupling between chemical, mass-transport, and mechanical non-linear processes that play a role in concrete degradation and crack formation. To achieve this, coupled numerical models were employed to simulate the relevant processes. The results indicate that the application of coupled numerical models can effectively identify the dominant non-linear processes governing the long-term degradation of concrete and the development of cracks within a TRU waste repository. These findings suggest a need to reconsider safety assessments that treat concrete as a homogeneous and continuous material, as they may overlook the complexities of concrete degradation and its implications for radionuclide migration.