Repair of Fatigued Steel Bridge Girders with Carbon Fiber Strips

Project summary:

This project investigates the use of carbon fiber composite strips to repair continuous hot rolled steel bridge girders that have fatigue fractures in their negative moment region. Cover plates were welded to the top of the top (tension) flange of these girders in the negative moment region. The fractures typically initiated at the end of the cover plate, which for older girders did not need to terminate in the positive moment region of the girder. The combined experimental/computational research will focus on determining the development length of the composite strip (and its adhesive) required to withstand cyclic fatigue loading and cyclically changing environmental effects. The adequacy of this repair scheme to retain the original strength and stiffness of the steel girder will also be assessed.