Rethinking the Bridge

Both ends are set in concrete footings. Fiber-reinforced-plastic panels are bolted over the tubes, which are then filled with concrete. The composite tubes eliminate the need for rebar or steel reinforcements, so there are no corrosion risks. They also do away with the need to build wooden forms to shape poured concrete pilings or supports, a process that can take up to two months. The tubes also protect the concrete from the environment so it won’t spall over time. Once the concrete cures, the arch is covered with gravel and fill and the roadway put down. Total construction time can be as little as two weeks. Currently, composite tubes have been used on single-span bridges up to 75-ft long (bridges under 75 ft make up 57% of the nation’s bridges) and multispan bridges up to 800-ft long. Several AIT bridges have been erected and they all saved time, money, materials, and the end result were aesthetically pleasing bridges that should last 100 years.