AIT Bridges has developed a new composite tub girder that could make it possible to replace a bridge within 72 hours, the Maine-based engineering firm says.
The new AIT CT Girder can be used on about 80 percent of bridges in the United States, according to the company. AIT touts the tub girder as low-cost, low-maintenance, corrosion-resistant, and 50 percent lighter than steel and 75 percent lighter than concrete girders.
“The CT Girder has the lowest life-cycle cost in the industry and many times the lowest initial cost when compared to similar steel and concrete solutions,” the company says.
AIT developed the girder with the University of Maine’s Advanced Structures and Composites Center. The company plans to first use the technology to replace the Grist Mill Bridge in Hampden, Maine, as part of a project funded by the Maine Department of Transportation.
AIT says it has been designing composite arch bridge systems commercially since 2010.
The new girder is made of lightweight fiber-reinforced polymer and can be used for bridges up to 100 feet long. It is supported by standard foundations of precast-concrete panel deck or a cast-in-place concrete bridge deck.
The company says the girder can last 100-plus years, and it can be used as a highway, rail or pedestrian bridge and wherever steel and concrete support girders are used.
“Our composite tub girder is, ultimately, going to be a game changer in the bridge construction sector,” says AIT Chairman and CEO Brit Svoboda. “It is versatile, strong but light weight, affordable and ultimately intended to replace concrete and steel girders in the marketplace.”