There is no more iconic site in Stuart Florida than the Roosevelt Bridge. On June 17 of 2020 it made national headlines because of extensive cracking and chunks of concrete breaking off and falling into the waters below. The local police closed both the southbound and northbound sections of the bridge that day; and the US Coast Guard warned of an imminent collapse, temporarily halting all maritime traffic from navigating under the bridge. Needless to say, the bridge needed immediate attention from the Florida Department of Transportation.
Originally built in 1996 to replace twin drawbridges, the Roosevelt Bridge is a segmental bridge that spans St. Lucie River on US Highway 1. The precast segments use post-tensioned steel cables to reinforce the concrete and span the multiple segments together. As moisture finds its way through the segmental seams, these cables can corrode and fail over time.
As engineers looked for solutions, they looked to a previous Florida DOT segmental bridge repair in Ft. Lauderdale. Why did this particular bridge get their attention? Sections of the I-75 connector to Sawgrass SR869 bridge was holding up after repairs far better than others, why? The difference was that the some of the seams were reinforced with an aramid synthetic fiber joint repair product.
Fortec (The Commercial division of Fortress) 5680 aramid fiber sheets were used on both the Sawgrass bridge and now the Roosevelt Bridge. The sheets serve two purposes: first, as a non-corrosive material they are able to seal the seams from moisture. Second, the strength of the aramid fibers adds reinforcement to the seams preventing excessive expansion and cracking.
The 8650 sheets were installed by Venture Construction on the most critical joints on the southbound bridge in October of 2020 and the northbound section of the bridge was repaired in December.
Aramid is a synthetic fiber used in multiple applications from aerospace to body armor. Kevlar®, made by Dupont, is the most recognizable aramid fiber based product and is also the raw material that Fortec uses in the manufacturing of their 5680 product. The technology and processes implemented in composites manufactured by Fortec have been perfected and utilized in multiple bridges and commercial structures for nearly 20 years.