Methodology for structural evaluation of corroded pre‐tensioned prestressed concrete girders considering spatially distributed pits

This study presents a methodology to evaluate the ultimate load‐bearing capacity of prestressed concrete girders subjected to chloride‐induced corrosion. The model accounts for bending, shear, and bond failure, incorporating the effects of localized wire ruptures and the resulting local reduction in prestressing force. The effects of pitting corrosion on the prestressing reinforcement are incorporated in terms of reduced cross‐sectional steel area and corresponding prestressing force, reduced ultimate steel strain, reduced bond strength between concrete and steel, and an increase in transfer length. The influence of these factors on the structural capacity is assessed. Additionally, spatially distributed corrosion pits are considered in the wires of the strands by scaling the average corrosion pit depth of each strand according to a spatially correlated scaling factor. The results show that incorporating spatial variability in the pits has a significant effect, typically resulting in lower values of the predicted load‐bearing capacity, particularly when extreme pits are aligned in one cross‐section of the structure. By combining the methodology for the structural evaluation with a two‐dimensional chloride ingress model, the degradation of the structural capacity is predicted over time.