Modelling the spatial-temporal progression of corrosion with special emphasis on its influence on structural reliability

Reinforced concrete (RC) structures constitute an essential part of the building infrastructure. This infrastructure is aging and a large number of structures will exceed the prescribed service period in the near future. The aging of concrete structures is often accompanied by corresponding deterioration mechanisms. One of the major deterioration mechanisms is the corrosion of the reinforcing steel, caused by chloride ions and carbon dioxide exposure. Corrosion is a complex physical, chemical and mechanical process. The modelling of this process is subjected to significant uncertainties, which originate from a simplistic representation of the actual physical process and limited information on material, environmental and loading characteristics. The present work proposes a probabilistic model for the assessment of spatial and temporal effects of corrosion for the estimation of structural reliability of a potentially corroded RC structure. The model is developed for the consideration of simply supported RC beams in flexure. In a case study various member spans, bar diameters and number of bars in a given cross-section are considered. The study concludes with an analysis of model results and a discussion on how the model can be extended to complex structural details and systems.