Flexure Behavior of Corroded Reinforced Concrete Beam

Abstract

The steel reinforcement within concrete beams is vulnerable to corrosion.In order to explore the flexural load-carrying capacity of beams under varying corrosion rates, a theoretical calculation and prediction model was proposed in this study. The study involved accelerated corrosion testing of three beams, with an additional beam serving as a control. A four-point bending test was conducted on all beams in accordance with predetermined corrosion rates. Strain gauges were positioned at the midspan to monitor strain data, and dial gauges were employed to measure deflection deformation at vulnerable sections. Experimental investigation was employed to ascertain the parameters that influence the deformation of a beam due to corrosion rate variations during loading, and the predictive model for the bending bearing capacity in relation to corrosion level was established. Results demonstrate the correlation between the elevated corrosion rate and the gradual increase in the average and maximal crack widths on the beam surfaces. The increase rate of maximal crack width exceeds the average, although both display a similar linear growth trend. The impact of corrosion on the initiation of crack and propagation in the test beams increase with high corrosion levels. Conversely, the effect of corrosion is limited when the corrosion rate remained below 15%. Nevertheless, once the corrosion rate exceeds 25%, a more pronounced effect becomes evident. Furthermore, the corrosion of steel reinforcement has a considerable effect on the yield and ultimate load-carrying capacity of the test beams. Upon reaching a corrosion rate of 25%, the flexural capacity of the corroded beams is found to be 54% of the uncorroded beams. This result indicates that as corrosion increases, the flexural capacity decreases linearly. This study offers a reference for accelerating the corrosion testing of reinforced concrete beams and predicting the bending bearing capacity of the corresponding corrosion level.