Predicting Corrosion Fatigue Crack Propagation Behavior of HRB400 Steel Bars in Simulated Corrosive Environments

Abstract

This paper systematically performed fatigue crack propagation (FCP) tests to investigate the corrosion fatigue crack propagation (CFCP) behavior of HRB400 steel bar. The fatigue loading scheme involved the constant amplitude loading and stepwise decreasing amplitude loading. The load ratio, the ratio of the minimum load to the maximum load, was designed as 0.1, 0.2, 0.3, 0.5, and 0.7. The test environments included air, pure water, 3.5% NaCl solution, and an electrolytic erosive environment. The FCP rate and threshold stress intensity under the test conditions were obtained and compared. An empirical model for predicting the CFCP rate was proposed, where the influences of load ratio and environment type were incorporated. The proposed model was validated using the test results. The results showed that the CFCP behavior of the rebar showed the feature of true corrosion fatigue. Increasing the environmental erosion level and load ratio increased the FCP rate and decreased the threshold stress intensity, indicating that the steel bar’s resistance to fatigue crack growth decreased. The predictions of the proposed model agreed well with the test data. This paper provided experimental and theoretical references for the corrosion fatigue life prediction of concrete structures.