||Fiber Reinforced Concrete (FRC) Beam End Repairs for Corroded Steel Beam Ends
Jason T. Provines
The Virginia Department of Transportation (VDOT) allocates approximately $215M every year on bridge maintenance and an additional $225M per year on replacement or major rehabilitation of structurally deficient bridges. One leading contributor to this costly maintenance is replacement or repair of corroded steel beam ends due to leaking joints. The typical strategy for repairing corroded steel beam ends is by bolting repair plates to the existing beam end or by cutting out the corroded section welding a new beam end in place. Sometimes this repair strategy can require jacking of the beam, which causes a disruption of traffic. Over the last decade, the University of Connecticut has conducted numerous research studies on a repair strategy in which ultra-high performance concrete (UHPC) is cast around the corroded steel beam end. Shear studs are also welded to intact portions of the steel beam for the UHPC to provide composite action. This was successfully implemented by the Connecticut DOT.
Due to its similar material properties to UHPC, it is quite possible that very high performance concrete (VHPC) could also be used for repairing corroded steel beam ends in a similar fashion. VDOT has had good experience with using VHPC in adjacent concrete member connections. In many cases, VHPC has better workability and costs less than UHPC.
This evaluation will include development of FRC (UHPC & VHPC) mixes in the concrete laboratory, field implementation of FRC beam end repairs, and evaluation of the repairs. Field implementation will include VTRC working with VDOT districts to select eight candidate steel beams for FRC repairs. Once the repairs are installed, they will be evaluated by structural load testing and condition evaluation. Results from the project will be used to develop VDOT guidance on the design, installation, and inspection of FRC beam end repairs.