In the wake of several natural disasters, department of transportation (DOT) offices are considering alternative materials to replace aging bridges. In D.C alone, the D.C. DOT replaced the concrete slabs and its encased steel beams with five-inch thick fiber-reinforced polymer (FRP) decks on three bridges.

Composite Advantage of Dayton, Ohio, provided the glass fibers held together by vinyl ester made with a base resin – the Derakane 610. Ashland Inc. supplied the Derakane resin. Composites Advantage is one of a handful of major U.S. manufacturers of composites parts for bridge applications. The largest FRP deck was installed in Massachusetts in 2013. The 18,776-square-foot bridge deck, originally built in 1883, was replaced with a lightweight fiberglass deck to better handle the weight of newer trucks.

There are more than 604,000 bridges in the U.S. and a recent report issued to Congress found that 11.7 percent are structurally deficient and about 14.2 percent are functionally obsolete. Even though 25.9 percent of U.S. bridges have issues, the figure is an improvement over the 30.7 percent that fell into these categories in 2000.

The use of composites for bridge decks continues to make strides within the industry at a slow but steady pace. “You are dealing with public safety so that industry has to be conservative,” Composite Advantage owner Scott Reeve said. “The other thing is, it took like 30 years — from the 1880s through 1910 — before steel totally displaced wood in bridges in this country so it’s going to take us some time, too. We’re in the middle of the process.”

In the near future, composite bridges will continue to replace deteriorating bridges across the country, saving state DOTs additional maintenance costs further down the road.