Nonlinear structural performance and seismic fragility of corroded reinforced concrete structures: modelling guidelines

Abstract

The current paper provides modelling guidelines for nonlinear analysis and fragility assessment of corrosion-damaged reinforced concrete (RC) structures. A systematic guideline is proposed to model the adverse impact of corrosion on mechanical properties of steel and concrete materials including the negative impact of corrosion on inelastic buckling and low-cycle fatigue (LCF) degradation of reinforcing bars. The proposed fibre-based modelling technique is capable of simulating the spatial variability of localised corrosion and the influence of corrosion on damage states (DS). Corrosion-dependent pushover and cyclic analyses, incremental dynamic analyses (IDAs) and fragility analyses are carried out on three different case studies: (i) a cantilever square RC column, (ii) a cantilever circular RC column and (iii) a RC frame. The analyses results indicate that corrosion significantly affects the DS, sequence of failure mode, flexural capacity and energy dissipation capacity of RC structures. Moreover, alongside the corrosion, the geometry of RC components also affects their failure sequence, cyclic behaviour and energy dissipation capacity. It is shown that increasing degree of corrosion penetration results in the concentration of damage mainly in confined concrete.