Corrosion fatigue life prediction for steel bar in concrete based on fatigue crack propagation and equivalent initial flaw size

Abstract

A new corrosion fatigue life prediction approach for steel bar in concrete based on fatigue crack propagation and equivalent initial flaw size (EIFS) was proposed, coupling corrosion growth and fatigue crack propagation together. By using fracture mechanics method and introducing the concept of EIFS, theoretical approach for corrosion fatigue life prediction was discussed, and the corresponding mechanical model was presented. Through accelerated corrosion test of reinforced concrete (RC) beams, the quantitative relation between corrosion pit depth and corrosion degree expressed by mass loss was established. Fatigue loading test of corroded RC beams was carried out, and the quantitative relation between EIFS and corrosion degree was presented according to the test results of corrosion fatigue life. The corrosion fatigue fracture of steel bar obtained by fatigue loading test was observed, and it is found that corrosion has no substantial effect on the critical crack size. Finally, the proposed corrosion fatigue life prediction model was validated by comparing with the existing experimental results, and the predicted values were in acceptable agreement with the test results. The findings of this study can be used to predict the fatigue life of aging corroded RC beams under corrosive environment.