Concrete cover delamination model for non-uniform corrosion of reinforcements

Abstract

Cover delamination failure caused by the corrosion of closely spaced rebars is commonly found in deteriorated reinforced concrete (RC) structures. However, analytical studies carried out on this failure mode of RC structures are rare. In response, this paper proposes a novel analytical model for cover delamination which takes into account the interaction between the neighboring corroded rebars, non-uniform distribution of rust around the steel/concrete interface, and boundary conditions of the concrete surface. This simple model enables manual prediction of the bulging deformation of the cover surface and the maximum thickness of rust. The predicted results are then verified with numerically derived results from a nonlinear finite element analysis. Finally, the effects of the rebar spacing, tensile strength of concrete and cover thickness on the bulging of the concrete cover surface and the maximum thickness of rust are studied with the verified analytical model.