Experimental and Analytical Investigation of the Fatigue Flexural Behavior of Corroded Reinforced Concrete Beams

The fatigue flexural behavior of corroded reinforced concrete (RC) beams was experimentally and analytically examined. Seven beams were constructed and tested, and an analytical fatigue prediction model (FPM) was proposed to assess the fatigue behavior of the corroded beams. After validating the FPM with the experimental test results, the FPM was then extended to better understand the effects of the degree of steel corrosion, the corrosion pit geometry, and the fatigue load level on the performance of corroded RC beams. The results show that the fatigue behavior of the corroded steel bars determines the fatigue behavior of the beams. Rebar corrosion has a significant detrimental effect on the fatigue performance of RC beams due to stress concentration, loss of steel cross-sectional area, and diminished bonding at the steel-concrete interface. The stress concentrations increase with increasing pit width-to-length and depth-to-diameter ratios. Differences in pit geometry and the resulting changes in stress concentrations due to corrosion should be considered when assessing fatigue performance.