Computational and analytical modelling of carbonation-induced spalling of the concrete cover

Concrete is one of the most abundantly used materials in the building industry and corrosion of the reinforcement steel is one of the main reasons of degradation in concrete structures.Corrosion of the rebars not only reduces the steel cross-section, it is also accompanied by a volume increase due to the formation of rust products, resulting in rising internal expansion stresses on the concrete.Eventually, cracks may form when the tensile stress reaches the tensile strength of concrete, and further propagation of these cracks towards adjacent rebars or to the surface may lead, respectively, to delamination and spalling of the concrete cover.In this work, spalling behaviour due to a uniform radial pressure, relevant for carbonation-induced corrosion, is analysed using a 2D Finite Element model.This numerical model is used to assess the adequacy of existing analytical models in literature predicting the peak pressure during spalling.The allowable peak pressure can be seen as a resistance against spalling, which may be related to the corrosion level and hence is relevant in relation to the reliability-based assessment of degrading structures.