The effect of non-uniform steel bar corrosion on pre-stressed RC members subjected to hysteretic load at the mid-span: experimental study and three-dimensional FEM modeling

In the chloride-rich environment, reinforced concrete (RC) structures may suffer from different types of non-uniform rebar corrosion (NURC). The effect of different types of non-uniform rebar corrosion on the cyclic behavior of RC beams under axial load has been studied here by experimental and numerical study. The structural behavior of three RC beams with the same dimensions and reinforcement configuration was examined under reversed cyclic loading. Two RC beams were subjected to different types of non-uniform rebar corrosion, and another beam was used as a sound specimen. The specimens were subjected to an axial load equivalent to 5% of the axial capacity. The obtained results revealed that cross-sectional non-uniformity leads to a notable difference in the yield strength, maximum strength, and stiffness in the positive and negative loading cycles. Nevertheless, interestingly the presence of corrosion pit did not affect the ductility of the RC beams. To predict the structural response of RC beams with different kinds of non-uniform corrosion and axial load, a numerical model was developed by extending the author's previous numerical model for RC beams. Thereafter, the numerical model was verified with the results obtained from the experiment. The obtained results revealed that the axial loading improves the displacement capacity and load-carrying capacity of the non-uniformly corroded RC beams significantly. Finally, a parametric study was carried out to examine the effect of different crucial factors on the cyclic behavior of RC beams subjected to various non-uniform corrosion and axial load.