A mesoscale damage framework is developed for investigating the extent of crack or damage penetration in a large-scale concrete component induced by corrosion process under various boundary conditions. The framework synthesizes a robust particle generation algorithm, a state of the art mesoscale damage model and a global optimization algorithm. Three-point bending experiments on geometrically similar specimens, designed to capture the size effect reasonably well, are reported and used as the basis for estimating mesoscale damage parameters. The results show how boundary conditions control damage evolution, realising scenarios from complete penetration to arrest of damage at different penetration levels within the component. In particular, it is shown that damage is arrested under external pressure and fixed displacement boundary conditions, but fully penetrates under stress-free boundary condition. The outcome is significant for the integrity assessment of concrete elements encapsulating corroding metallic containers.