Composite jackets for rehabilitation of damaged reinforced concrete pier caps

A fiber-reinforced polymer (FRP) composite jacket was constructed to rehabilitate a damaged reinforced concrete pier cap of a bridge in Rhode Island. The unique feature of the construction was the use of in-situ vacuum-bagging technique. The reinforced concrete pier cap was damaged due to corrosion of steel reinforcement leading to spalling of the concrete cover. The two composite jackets covered the top and sides of two pier caps that were 15.5 meters long, 1 meter wide, and 1.2 meters deep. The composite jacket consisted of fiberglass reinforcement and epoxy matrix. This experimental research project was undertaken to evaluate whether the vacuum-bagging technique commonly used by the aerospace industry can be adopted for bridges under field conditions. The results indicate that the technique is viable and provides much better bonds to weathered concrete surface by eliminating the air bubbles and air pockets at the concrete-FRP interface. The construction details outlined in this paper consist of surface cleaning, priming, fabric application, vacuum bagging, and post-curing. The long-term performance of the composite jacket is currently under evaluation.