Modelling the Stiffness Reduction of Corroded Reinforced Concrete Beams after Cracking

The serviceability of reinforced concrete structures (i.e., bending stiffness) is mostly affected by the corrosion of the tension reinforcement (steel cross-section and the steel-concrete bond reduction). This paper presents two models aiming to predict the stiffness degradation of corroded reinforced concrete beams particularly after cracking. The two modelling approaches are: beam Macro-Finite-Elements (MFE) using cross-section analysis developed at the LMDC Toulouse and 2D nonlinear finite element analysis developed at Politecnico di Milano. Both, the steel cross-section and bond reduction versus corrosion rate are taken into account. The models are validated by simulating tests on a 23 year old corroded beam from long term experiments still in progress at LMDC. Results show a good agreement between both simulations and the experimental responses and highlight the predominant influence of the steel-concrete bond loss.