Shear and flexural strength of corroded R.C. beams

Simplified equations aimed at evaluating the flexural and shear capacity of corroded R.C. beams are presented and discussed in this paper, with reference to ordinary beams reinforced both longitudinally (with same-size bars) and transversely (with stirrups). A model is developed to take care of diffused and localised corrosion (pitting corrosion), concrete decay in compression and bond-strength decay at concrete-reinforcement interface. A fairly innovative contribution of this study is the introduction into the proposed equations of the main parameters governing the corrosion processes. The proposed approach is simple and effective, and may be adopted in the assessment of many damaged structures (a) on the basis of the available experimental information (e.g., carbonation depth, chloride content, pit depth and size in the bars and mass loss in the reinforcement), and (b) by utilizing analytical expressions calibrated through the knowledge of the density of the corrosion current.