CORROSION FATIGUE OF BRIDGE STEELS. VOLUME I. EXECUTIVE SUMMARY. FINAL REPORT

The research program and test results described in this report deal with the role that environment plays on the fatigue response of bridge steels and weldments. Three key program elements are: small sample fatigue crack propagation studies of bridge steels and weldments in air and aqueous environments; small sample crack initiation studies of bridge steels and weldments in air and aqueous environments; and fatigue tests of full size bridge weldments in air and aqueous environments. The crack initiation studies indicated a reduction in the fatigue life of the samples for all combinations of environments and materials tested. The results of the fatigue crack propagation studies showed an apparent elevation in the fatigue thresholds for the material and environmental conditions tested, and no apparent change in the region II behavior. The full size beam weldments showed a slightly lower number of cycles to first crack detection in a water and a 3.5 percent NaCl-water environment as compared to air data. The total number of cycles to failure of the full size weldments in water were similar to those observed in other studies. The material presented in this volume provides an Executive Summary of the research program. As such, it highlights key points of the experimental program and the recommendations and conclusions of the study.