Glass fiber pultrusion technology opens up a new era for Bridges

Recently, a composite arch highway bridge was successfully built near Duval, Washington. The bridge was designed and manufactured under the supervision of the Washington State Department of transportation (WSDOT). The authorities praised this cost-effective and sustainable alternative to traditional bridge construction.
The composite bridge structure of AIT bridges, a subsidiary of advanced infrastructure technology / AIT, was selected for the bridge. The company developed the composite arch technology originally developed by the center for advanced structures and composites of the University of Maine for the army, and also developed the bridge deck made of glass fiber reinforced plastic that can be laid on the bridge arch.
AIT bridges produces hollow tubular arches (garches) and glass fiber reinforced plastic deck (gdeck) at its plant in brewer, Maine. The site only needs simple assembly, covering the bridge deck on the bridge arch, and then filling it with reinforced concrete. Since 2008, the company has assembled 30 composite bridge structures, mostly on the east coast of the United States.
Another benefit of composite bridge structures is their long life and low life cycle cost. Before awarding the exclusive contract to AIT bridges, the Washington State Department of transportation carefully reviewed all engineering data on the ability of composite arch bridges to resist fire and the impact of objects such as floating wood. “Earthquakes are also a concern,” Gaines said. This project is the first time I know of using composite arch bridge in Highland earthquake area, so we want to ensure that it meets the seismic design requirements. We threw a lot of difficult questions to AIT bridge. But in the end, they answered all our questions one by one, and we could move forward with the project with more confidence“
The results show that composite bridges can deal with almost any dangerous situation. “We found that the bridge is actually more earthquake resistant than the current traditional structure. The rigid concrete structure can not easily move with the seismic wave, while the flexible composite arch can swing with the seismic wave and then return to its original position,” Sweeney said. This is because in the composite bridge structure, the concrete reinforcement is nested in the hollow pipe, which can move and be buffered in the hollow pipe. In order to further strengthen the bridge, AIT strengthened the anchor connecting the bridge arch and concrete base with carbon fiber. ”
With the success of the project, the Washington State Department of transportation updated its bridge specifications to allow the construction of more composite bridges. Sweeney also hopes that you can experience the many benefits provided by composite bridges and encourage the further use of composite bridge structures on the west coast. California will be the next expansion goal of AIT bridge.