Crumbling reinforced concrete and exposed, rusting steel rebar, coupled with a requirement to reduce dead load on old stone canal walls, demanded a lightweight bridge deck solution for the District of Columbia’s 29th Street Bridge.
The project also had to be completed in half the time normally reserved for bridge deck replacement work due to logistics challenges associated with utility lines that ran beneath the bridge.
To meet these requirements, the District Department of Transportation (DDOT) chose Composite Advantage's FiberSPAN fibre-reinforced polymer (FRP) bridge deck product.
FiberSPAN is a prefabricated bridge element that is moulded as a complete panel section for ease of installation. FiberSPAN is a sandwich panel consisting of thick fibreglass facesheets on top and bottom of a fibreglass reinforced closed cell foam core.
| The DDOT and its consulting engineer evaluated several design options. This configuration was chosen because bridge depth was very restricted. The bridge had to clear tour boats using the canal but match the existing street level. Using longitudinal steel beams for high bending stiffness, we designed the FiberSPAN deck within an allowable depth of 5 inches and tested it to demonstrate its ability to support required truck loads. |
| Scott Reeve, president, Composite Advantage |
Five lightweight, corrosion resistant FiberSPAN bridge deck panels were installed in just 1 day on a steel beam superstructure. It took only one more day to bolt the panels to shear studs welded to steel beams and add a fibreglass reinforced polymer (FRP) sidewalk.
The new FRP short span bridge, 39 ft long by 32 ft wide, has a fibreglass reinforced sidewalk panel bonded across its west side. Granite curbs are attached on the deck’s edges.
The bridge deck has an asphalt wear surface while pavers added to the sidewalk match its surface to adjacent walkways.
The bridge helps support the canal’s older stone walls and maintain their vertical position.
The FRP sidewalk is a new feature Composite Advantage made available to designers.
