The bridge that crosses Carter Creek on Southview Drive in Rolla is an unassuming structure, but researchers at the University of Missouri-Rolla have been paying close attention to what’s hidden beneath the concrete. And so far, the researchers like what they see.
In 2004, Rolla city officials allowed UMR researchers to construct the bridge to demonstrate the use of the latest in fiber-reinforced polymer (FRP) composites, materials that were first developed for use in the aerospace and automotive industries.
“Ultimately, this research will produce safety improvements, reduce public costs and achieve technology advancement, all primary goals of UMR, the Missouri Department of Transportation and of the City of Rolla,” says Dr. Antonio Nanni, an expert in the development of new construction materials, who joined UMR in 1997 but recently accepted a new position at a Florida university.
The bridge has a split personality. One lane was built using convention technologies. The other lane employs a FRP-reinforced concrete deck. The FRP deck, attached to the walls using glass fiber-reinforced polymer (GFRP) anchoring bars, uses both GFRP bars for tension reinforcement and carbon fiber-reinforced polymer (CFRP) prestressed tendons to enhance the deck’s performance under both ultimate and service loads.
Two systems were designed by UMR and Rolla Technical Institute to prestress the CFRP tendons. RTI students constructed the systems to “make students familiar and eager to learn innovative technologies,” says Max Vath, who supervised the students.
The use of FRP bars as internal reinforcement for concrete has been increasing steadily over the last several years, say Dr. Nestore Galati, a research engineer in the Center for Infrastructure Engineering Studies (CIES) at UMR. The CIES is closely aligned with another research initiative on campus: the national University Transportation Center, which is one of 10 in the nation that focuses on non-destructive testing technologies and advanced materials for strengthening bridges, roads and buildings.
“FRP has many advantages over conventional steel reinforcement, such as high tensile strength, light weight, and corrosive resistance,” Galati explains. “These advantages make it an ideal alternative reinforcement.”
The final report on the bridge will be available Tuesday, Aug. 1, online at www.utc.mst.edu.