Numerical evaluation of the seismic performance of existing reinforced concrete buildings with corroded smooth rebars

Exposure to aggressive environments is one of the most critical problems of reinforced concrete (RC) structures, which can affect both their static and dynamic behaviour. In this paper, the linear and non-linear performance of existing corroded RC framed structures were studied through an advanced numerical model. Moreover, an extensive literature review of models and approaches used for the assessment of RC structures exposed to different levels of corrosion was presented. The numerical evaluation of an existing RC structure subjected to different exposures and degradation was considered. A new approach was presented for the evaluation of the ultimate capacity of RC elements. Such an approach has been compared and validated against a set of the experimental results from the literature. The results of comparative analyses showed that the proposed approach could predict the ultimate capacity of corroded RC components. Linear and non-linear analyses were performed using a refined Finite Element method; the seismic performance evaluated in terms of shear strength degradation, inter-storey displacements, ductility, and maximum base shear. The outcomes of the present study demonstrated that corrosion had a significant impact on the structural response of the existing building. Such an effect depended on the type of exposure. The elastic dynamic analyses of the building demonstrated that corrosion increased the fundamental periods and, changed the mass participation factor and the mode of vibration, i.e. the external exposure. Non-linear static analyses showed a significant reduction of the shear capacity and the translation ductility with the increase of the corrosion rate for all lateral loading patterns specified by the Eurocode. The results of the non-linear dynamic analyses illustrated that the damage and deterioration due to the corrosion attack increased the roof and the inter-storey drift-ratios, as well as a relevant decay of the base shear capacity and early collapse were noted for high-levels of corrosion. Comparisons between non-linear static and dynamic analyses were also provided in terms of roof drift-ratios and base shears.