Validation of thick-walled cylinder analogy for modelling corrosion-induced concrete cover cracking

Abstract

The main objective of this paper is to validate the use of the thick-walled cylinder (TWC) analogy to model corrosion-induced crack propagation in reinforced concrete (RC) structures. The TWC analogy neglects the effects of member geometry to create an idealized axisymmetric stress state. Although this simple approach has been used by many researchers, its suitability to various geometries and reinforcement configurations has not been comprehensively investigated previously. To achieve this goal, four different geometries are modeled using finite element analysis. The finite element models are two-dimensional, and they consist of plane membrane, quadrilateral elements under plane-stress conditions. Corrosion-induced expansion at the rebar/concrete interface is simulated using truss elements subjected to an equivalent thermal load. As a part of this validation, the effect of an adjacent corroding rebar and asymmetry of geometry were also investigated. The results are compared against the analytical solutions found using the TWC analogy. This study found that, in general, the use of the TWC analogy to model corrosion-induced cover cracking is appropriate; however, its limitations are also discussed.