An overview on finite element-modelling techniques for structural capacity assessment of corroded reinforced concrete structures

About 80% of the observed damage in existing reinforced concrete structures is related to corrosion. Typical corrosion-associated phenomena that affect structural capacity concern: (i) cross-section and ductility reduction of steel, (ii) concrete cracking, (iii) concrete area reduction due to spalling and (iv) modification of the bond properties. A number of models have been presented in recent years addressing these issues. The paper presents a critical review of such models and their application to the analysis of corroded reinforced concrete members using nonlinear finite element analysis. The accuracy of different modelling approaches is assessed through comparison with experimental results on corroded beams subjected to monotonic and cyclic loading. Specimens showing different failure modes were selected, such as flexure, combined flexure-shear and bond failure. Sensitivity studies are performed in order to gain better understanding of the contribution of each degradation phenomenon. Finally, recommendations are given for reliable capacity assessment of existing concrete structures affected by corrosion.