Calculation Method of Normal Section Flexural Capacity of Corroded Reinforced Concrete Rectangular Beams

Based on the experimental data of 48 corroded reinforced concrete(RC) beams,the laws of the flexural capacity of the reinforced concrete rectangular beams with different corrosion ratios were studied,the assumption of plane cross-section was verified and the relation between the strain of steel bar and the strain of the concrete corresponding to the steel bar in the ultimate state of the beams was gained when the assumption of plane cross-section no longer came into existence.Through the constructed geometrical condition,the formula of the compressive region height corresponding with different corrosion ratios of the RC rectangular beams with plain steel bar and twisted steel bar was given.Then,calculation formula of normal section flexural capacity of corroded reinforced concrete was deduced and it was verified by the experimental data.Test results show that strains of steel bar and concrete no longer conform with the assumption of plane cross-section under corroded state of steel bar.Results calculated by proposed flexural capacity formula are accurate and reliable.The calculation method of flexural capacity can be used to guide engineering practice.