Fatigue-Life Prediction of Corroded Steel Bar Based on Fractal Theory

Abstract

This paper presents an experimental study that sought to characterize the effect of corrosion and fatigue load on the behavior of reinforcing steel bars. The surface profiles of corroded steel bars and the relationship between fatigue life and corrosion morphology were investigated. First, the corrosion process was accelerated by applying external direct current. Next, fatigue tests were performed on uncorroded specimens and precorroded specimens, and the results are presented and analyzed. A method for calculating the three-dimensional (3D) corrosion morphology coefficient of corroded steel bar is proposed. The fatigue life of corroded bars is significantly reduced because of corrosion morphology, and a logarithmic linear relationship exists between fatigue life and the corrosion morphology coefficient. Considering the corrosion morphology of corroded steel bars, a method is provided to calculate the fatigue life of a corroded steel bar based on the properties of uncorroded steel bar and the 3D surface morphology coefficient of corroded steel bars. The prediction results for corroded steel bars agree well with the experimental observations.