Performance of weathering steel in bridges

This report contains the findings of a comprehensive assessment of the performance of weathering steel in bridges based on a review of the literature, a survey of practice in highway agencies and other organizations, and contact with selected individuals knowledgeable on the subject. The report should be of value to structural engineers and others interested in the design, construction, and maintenance of steel bridges. The objectives of this research project are (1) to assemble a systematic body of information on the performance of weathering steel, (2) to document and evaluate the current state of practice, and (3) to develop, where feasible, practical guidelines for design, construction maintenance, and rehabilitation of bridges using this material. The findings of the first phase of research are presented in this report and relate primarily to the first two objectives. In Phase I, problems that have developed in bridges were identified, and other factors that have limited the use of weathering steel in the United States and abroad were analyzed. The topics considered included: corrosion, salt exposure, other environmental factors, pitting, fatigue, in-service inspectability, location within the bridge, structural details, shims and bearings, bolted connections, welding, adequacy of specifications, alloy content of the steel, initial cleaning and painting, remedial cleaning and painting, and adverse effects of corrosion on fatigue life. In addition, existing experimental and field performance data were assembled, and the current state of practice in regard to the use of weathering steel in bridges was evaluated.