FYFE PLAYS A KEY PART IN THE“RESTORE THE CORRIDOR” PROJECT
FYFE PLAYS A KEY PART IN THE “RESTORE THE CORRIDOR” PROJECT Location: The Brandywine River Bridge, Delaware OVERVIEWThe Brandywine River bridge makes up a portion of the DelawareTurnpike, carrying I-95 traffic over the Brandywine River inWilmington, Delaware. The bridge was constructed throughout themid-1960s and, as it happens, the opening ceremony for the DelawareTurnpike was one of John F. Kennedy’s last public appearancesbefore his assassination.The bridge is currently under construction as part of a $200 millionproject dubbed “Restore the Corridor.” ISSUEWhen this project was in its planning phases, the structural engineerswere tasked with analyzing the bridge using today’s design vehicleloads. The bridge contains two types of piers, hammerhead piersin the approach spans and arch piers in the middle spans. Thestructural engineers decided the strut-and-tie method was themost appropriate and accurate way to analyze these piers. This isa relatively new analysis method that did not exist when the bridgewas designed in the early 1960s. The results of the analysis indicatedthat the hammerhead piers required shear reinforcement throughouttheir cantilevered sections and negative flexural reinforcement abovetheir stems. The arch piers required shear reinforcement throughouttheir interior and exterior overhangs, positive flexural reinforcementin their interior overhangs, and negative flexural reinforcementabove their verticals. Externally bonded carbon fiber reinforcedpolymer (CFRP) was chosen as the means of reinforcement due toits light weight, low profile, and ability to maintain the aesthetics ofthe substructure units once painted. SOLUTIONIn early 2021, the CFRP installation scope was awarded to TitanIndustrial Services, a Fyfe certified installer based out of Baltimore,MD. CFRP installation began in the summer of 2022 and is currentlyon hold due to the lower winter temperatures in Wilmington, DE.On the engineering side of things, one of biggest challenges wasdealing with the steep curves of the arches in areas that requiredshear reinforcement. Recognizing that it would be very difficult, ifnot impossible, to install “U” shaped wraps in these locations whilekeeping the vertical legs vertical, Fyfe engineers came up with an“L” shaped wrapping detail. This proved to be a successful conceptas Titan Industrial Services was able to install these wraps per Fyfe’sdetail without much trouble. However, construction is never withoutits challenges. Most of the piers were easily accessible with a manlift,but Pier 6 required swing staging. Titan Industrial Services attached40’-0” swing stages on each side of the capbeam of Pier 6, whichmade accessing the vertical faces easy. The challenge was trying topass the saturated rolls of fiber from one swing stage to the otherunder the 6’-8” wide capbeam! Arch Pier During Construction, circa 1964 Aerial View of Bridge Piers Prior to Superstructure Installation, Jan. 30, 1964 Surface preparation Installation of Fyfe’s Tyfo SCH-41 2X CFRP System Above Arch Vertical for Negative Flexural Reinforcement Another challenge was installing the positive flexural reinforcement on the undersides of the arch piers. Titan Industrial Services did not get to this until the Fall of 2022, when temperatures had started to drop. Lower temperatures result in epoxy-based systems requiring more time to cure. This can be a good thing, as it extends the working time of the epoxy, but it can also make overhead installations, where the installation team is working against the force of gravity, more difficult. To compound this, Fyfe’s design called for multiple plies of Tyfo SCH-41 2X, Fyfe’s “double thickness” unidirectional carbon fiber. This fabric is obviously heavier than Fyfe’s standard thickness Tyfo SCH-41 fabric. Closely monitoring the temperature throughout the day, only attempting to install this fiber during the warmest windows, and not trying to install too many layers at once were critical to Titan Industrial Services’ success on the project. Overall, Titan Industrial Services is pleased with what they were able to accomplish in 2022 and look forward to successfully completing the CFRP installation by the end of the 2023 season. Installation of “L” Wraps of Fyfe’s Tyfo SCH41 2X CFRP System for Shear Reinforcement FyfeCo.com | FyfeInfo@cs-nri.com | +1.855.708.3617 © 2023 FyfeFRP, LLC. All rights reserved. Fyfe® and Tyfo® are the registered trademarks of FyfeFRP, LLC. V: 01.01.23