In-Situ Verification of Rehabilitation and Repair of Reinforced Concrete Bridge Bents under Simulated Seismic Loads

Three in-situ tests were performed on two bents of a reinforced concrete (RC) bridge under quasi-static cyclic loads. The bridge was built in 1963 and did not possess the necessary reinforcement details for ductile performance. The tests included an as-built bent, a bent rehabilitated with carbon fiber reinforced polymer (FRP) composite jackets, and a damaged bent repaired with epoxy injection and carbon FRP composite jackets. Two new concepts of strengthening bridge bents with FRP composites were implemented in this study. The first involves shear strengthening and confinement of a beam cap-column joint through an FRP composite “ankle-wrap.” The second is an FRP composite “U-strap” to improve the anchorage of column longitudinal steel reinforcement extending into the joint. FRP composite jackets were also implemented in the columns and beam cap. An additional rehabilitation measure was that of anchorage of the piles to the pile cap using epoxied high strength steel bars. The performance of the bent in the as-built condition and that of the rehabilitated and repaired bents is described in terms of strength, stiffness, displacement ductility, and energy dissipation.