Corrosion-induced cracking behaviour of RC beams: experimental investigation, empirical modelling, and finite element analysis

This study investigates corrosion-induced cracking in reinforced concrete (RC) beams through experiments, empirical modelling, and finite element (FE) analysis. Specimens corroded using the galvanostatic (GS) and artificial chloride environment (ACE) methods were examined using X-ray imaging and surface crack-width measurements. The effects of cover-to-diameter ratio, rebar spacing, rebar position, and corrosion environment on crack development were systematically analysed. The results show that a smaller cover-to-diameter ratio and wet-dry cyclic exposure led to larger mean crack width at similar average corrosion levels. For multi-rebar RC members, corrosion-induced cracking is strongly influenced by rebar position and spacing; corner rebars dominate surface crack propagation, whereas crack development around the centre rebar is restrained by interactions between adjacent rebars. Based on these findings, a mean-level empirical model incorporating sectional parameters, environmental effects, and position-spacing correction factors is proposed within the investigated parameter range. The model was evaluated using data from previous studies and compared with existing empirical models, showing relatively stable performance in terms of prediction errors. In addition, a corrosion product expansion model was implemented in FE analysis to provide a mechanistic interpretation of the observed cracking behaviour and supplementary numerical evidence for the applicability and limitations of the empirical model.