OVERVIEW
The Brandywine River bridge makes up a portion of the Delaware
Turnpike, carrying I-95 traffic over the Brandywine River in
Wilmington, Delaware. The bridge was constructed throughout the
mid-1960s and, as it happens, the opening ceremony for the Delaware
Turnpike was one of John F. Kennedy’s last public appearances
before his assassination.
The bridge is currently under construction as part of a $200 million
project dubbed “Restore the Corridor.”

ISSUE
When this project was in its planning phases, the structural engineers
were tasked with analyzing the bridge using today’s design vehicle
loads. The bridge contains two types of piers, hammerhead piers
in the approach spans and arch piers in the middle spans. The
structural engineers decided the strut-and-tie method was the
most appropriate and accurate way to analyze these piers. This is
a relatively new analysis method that did not exist when the bridge
was designed in the early 1960s. The results of the analysis indicated
that the hammerhead piers required shear reinforcement throughout
their cantilevered sections and negative flexural reinforcement above
their stems. The arch piers required shear reinforcement throughout
their interior and exterior overhangs, positive flexural reinforcement
in their interior overhangs, and negative flexural reinforcement
above their verticals. Externally bonded carbon fiber reinforced
polymer (CFRP) was chosen as the means of reinforcement due to
its light weight, low profile, and ability to maintain the aesthetics of
the substructure units once painted.

SOLUTION
In early 2021, the CFRP installation scope was awarded to Titan
Industrial Services, a Fyfe certified installer based out of Baltimore,
MD. CFRP installation began in the summer of 2022 and is currently
on hold due to the lower winter temperatures in Wilmington, DE.
On the engineering side of things, one of biggest challenges was
dealing with the steep curves of the arches in areas that required
shear reinforcement. Recognizing that it would be very difficult, if
not impossible, to install “U” shaped wraps in these locations while
keeping the vertical legs vertical, Fyfe engineers came up with an
“L” shaped wrapping detail. This proved to be a successful concept
as Titan Industrial Services was able to install these wraps per Fyfe’s
detail without much trouble. However, construction is never without
its challenges. Most of the piers were easily accessible with a manlift,
but Pier 6 required swing staging. Titan Industrial Services attached
40’-0” swing stages on each side of the capbeam of Pier 6, which
made accessing the vertical faces easy. The challenge was trying to
pass the saturated rolls of fiber from one swing stage to the other
under the 6’-8” wide capbeam!