Comprehensive study on corrosion induced structural deterioration of steel bars in reinforced concrete beams

The structural degradation of steel bars in reinforced concrete (RC) beams due to the adverse effects of corrosion is a leading cause of the increasing likelihood of RC beam failure. Through the previous researches, it can be seen that the mechanical properties, crack initiation threshold, fracture threshold, and fatigue life of steel bars are closely linked to their corrosion profiles and the corrosion levels. However, due to limitations of testing equipment, accurately identifying the corrosion profiles of corroded steel bars has proven challenging. Therefore, at present, only predictive models have been established using regression analysis to investigate the mechanical properties and fatigue performance of corroded steel bars, and corresponding theoretical models for their assessment have not yet been developed. In order to establish corresponding theoretical models for precise evaluation of the mechanical properties and fatigue performance of corroded steel bars. Firstly, an artificial accelerated corrosion test was conducted on steel bars to assess their mechanical properties and fatigue performance. Different levels of corrosion were analyzed to understand the associated failure modes and to determine the cracking threshold and fracture threshold of the corroded steel bars.Secondly, a 3D scanner was employed to capture the surface profiles of steel bars with varying degrees of corrosion. Based on the data gathered from these scans, predictive models were developed to assess the mechanical properties and fatigue performance of corroded steel bars. Furthermore, corresponding finite element models were established to further investigate the impact of steel wire corrosion on the remaining service life of the bars. The results of our research demonstrate the effectiveness of the load-bearing capacity assessment proposed in this paper, as it accurately predicts the load-bearing capacity of corroded wires and aligns well with experimental findings. Additionally, our study revealed that the cracking threshold value for all types of steel bars exceeded 6.2 MPa & sdot;m1/2, and the fracture threshold intensity factor decreased as steel bars experienced more severe corrosion.