Wednesday, June 6th, 2012
In another display of the economic and performance efficiency of plastic composite technology, the decking for one of the world’s largest composite pedestrian/bicycle bridges was installed last week in just three days. Part of the District of Columbia’s Anacostia Riverwalk Trail Project, the 685-ft-long and 16-ft-wide seven-span bridge lets foot and bicycle traffic cross a road and active railroad tracks in safety.
The 88 composite decking panels that complete the bridge each weigh 1,250 lb, are 8-ft long and 3.5 inches thick, and employ a sandwich construction of fiberglass top and bottom skins enclosing closely-spaced internal webs that function like a series of I-beams.
The combination of straight and curved panels that turn the bridge’s graceful S-curve design into reality were designed and built by Composite Advantage LLC (Dayton, OH), and form the company’s largest project to date. The deck panels feature a non-slip wear surface that, like the rest of
the structure, is colored beige to meet customer specifications.
Composite Advantage was able to shrink onsite construction time and cost by prefabricating scuppers for drainage and curbs that would hold handrails and light posts. It also built electrical junction boxes for the lighting system into the panels and bolted clips to the bottom of the decking that connected the panels to the steel support beams.
And it’s no exaggeration to say that along with the high functionality and cost/time savings from using plastic composite technology, the finished product is an attractive bridge that will hold its good looks for a long time. Composites clearly can create amazing airplanes and high performance autos, but the technology holds multiple promises for infrastructure that will outlast and outperform the old alternatives.