“The lack of solid performance data has been one of the major roadblocks to widespread use of composite bridges,” says Dayakar Penumadu, the Fred N. Peebles Professor in the University of Tennessee Tickle College of Engineering and characterization fellow in the materials and processing group for IACMI. UT researchers and students will continue to monitor the bridge’s performance remotely through cloud computing. (The public can view monitoring data at compositebridge.org.)

“Although it’s a small span, it’s designed as a highway bridge deck, so all of the sensing data that we will be gathering is similar to what we would be seeing on a highway bridge. It’s a very low-risk way to gather real-time data that will give DOTs some confidence in the technology,” McCay says.

The team plans to develop a comprehensive case study comparing the total costs of a typical concrete bridge and one using an FRP bridge deck. “We will share the case study framework and results with federal, state and local officials, transportation departments and the civil engineering community so FRP composites will be more of a ‘known’ to them,” says Unser.

McKinney Excavating demolished the existing bridge and built the concrete foundation for the FRP composite decking. Other companies that contributed to the project included Compsys Inc. (PRISMA® composite preforms), Interplastic Corporation (resins), West System (epoxy resin), Superior Fiberglass and METYZ (fiber reinforcements) and AcraLock (adhesives).

All of the partners agreed to contribute their labor and materials. This was welcome news for Morgan County, which, like many rural communities, has a very limited budget for infrastructure repairs. Since the bridge has a 100-year life span, the county will also save money long term.

There was a benefit for Morgan County motorists as well. Since the bridge decking was manufactured in the factory rather than in the field, they didn’t have to deal with long, inconvenient road closures.

Structural Composites designed the bridge and built the decking in two modules, both measuring 8 x 25 feet. Each module consisted of two single-skin PRISMA preform sections, which were joined together in the factory at the raised frame caps.

“The two sections can be produced with a range of production methods, from low-volume open molding to closed molding to continuous molding,” says Scott Lewit, president and co-founder of Structural Composites. “They can be made to work with open molding/wet lay-up or adapted to infusion or to vacuum assisted resin transfer molding. This allows the technology to scale based on the manufacturing base and market demand.”