Predicting the shear strength of concrete beams with corroded rebar: a review and synthesis

The load-bearing mechanism in reinforced concrete beams with corroded rebar has not been clearly elucidated, impeding good shear strength predictions. A thorough literature review reveals the impact of rebar corrosion on the load-bearing mechanism of beams. A systematic validation confirms deficiencies in the current prediction approaches such as the failure to reflect changes in the load-bearing mechanism caused by rebar corrosion and insufficient consideration of the effects of key variables. Corrosion impact factors that reflect the enhancement of arch-action caused by main bar corrosion and the section loss of corroded stirrups are derived to better account for changes in the shear strength. The superiority of incorporating these impact factors into fundamental methods for intact beams is confirmed using ample published experimental data. Incorporating corrosion impact factors into Niwa’s formula is shown to yield the best predictions.