Assessment of a 60-year-old corroded concrete girder through finite-element analysis

This study implements a two-dimensional nonlinear finite-element approach for the assessment of the shear behavior of a post-tensioned bridge girder whose tendons and reinforcement suffered severe corrosion during its service life of almost 60 years. The girder is lightly reinforced with vertical stirrups and its tendons follow a parabolic profile, with many of them anchored at the top of the girder; as such, the contribution of post-tensioning is significant to its shear capacity. The objective of the study is to understand the various aspects of the progressive damage of the girder due to increased corrosion of its prestressing steel. Through the finite-element modeling tool, different approaches have been considered to model the corrosion of post-tensioning tendons and reinforcement to assess the shear response of the girder in the degraded state.