Bridging the Gap: College of Engineering Brings Innovation to Bridge Design
Steel reinforcement for concrete has traditionally dominated bridge building and design. But now, a group of forward-thinking students and faculty members at the College of Engineering are helping examine ways to eliminate corrosion from bridges by using composite materials instead.
Using a variety of fiber-reinforced polymers (FRP), the team in conjunction with the engineer of record (Brill Rodriguez Salas & Associates Inc.) and the general contractor (OHL-Arellano Construction Company) designed and built the Innovation Bridge at the University’s Coral Gables campus. They were able to replace steel reinforcement and pre-stressing cables, creating a structure that is stronger, lighter, cost-effective and, most importantly, corrosion-free – thereby reducing the need for costly maintenance. With corrosion recognized as one of U.S. government’s largest asset-management costs, this new bridge design could be a game-changer for communities around the country.
The Innovation Bridge, built by the University, is 70 feet long and began construction in November 2015. Connecting the campus to the athletic fields, the project provided quantifiable proof of concept when it was completed in May 2016; it remains a “living lab” for engineering students and faculty members, who monitor the bridge and use it as a teaching tool for others. The project leaders at the College wrote about the Innovation Bridge and the College’s work with FRP reinforcement in the November 2016 issue of Concrete International magazine. Now, the team is seeing its innovation come to life again in a project to rebuild the Halls River Bridge in Homosassa Springs, Florida (north of Tampa). In this project, the College together with Florida State University (FSU) is supporting the efforts of the Florida Department of Transportation, U.S. Department of Transportation Federal Highway Commission, Citrus County. The approximately $7 million bridge will be reinforced with FRP composites (made mostly of glass and carbon fibers), which should resist corrosion and the marine environment it must contend with. The structure uses groundbreaking solutions that have the potential to change the way bridges are built. The Department of Civil, Architectural and Environmental Engineering is conducting with FSU a two-year program to monitor and test the durability of the composite reinforcement.
“The Halls River Bridge project is a proof of concept for next-generation bridge designs and construction using a variety of fiber-reinforced polymers,” says Antonio Nanni, a professor and chair of the College’s Department of Civil, Architectural and Environmental Engineering. “This project is an example of how to make FRP-concrete structures – including piles, beams, seawalls and decks – that are more durable, stronger and safer than today’s construction.”
The first commercial applications of construction with FRP reinforcement took place almost three decades ago. “This method is finally at the dawn of widespread acceptance and use,” Nanni says. “It’s perhaps the most suitable response to the durability issues inherent in concrete construction. In addition, composites in general allow for innovations in reinforcement forms, fabrication and delivery. They have the potential to increase the quality of concrete construction, make construction easier and improve its overall performance.”