The Michigan Department of Transportation (MDOT) is continuing to deploy carbon fiber to reinforce bridge components as a way to reach their goal of bridges that last 100 years.
Calling it “game changing technology,” MDOT said that since 2011, it has been collaborating with Lawrence Technological University (LTU) in Southfield to research carbon fiber reinforced polymer materials in concrete bridge beams. The research, the department said, has moved from the lab into the field and that some projects have been deployed.
“The aim is bridges that last a century with minimal maintenance,” said State Transportation Director Paul C. Ajegba. “This technology, developed here in Michigan, is becoming wildly popular all over the country.”
The department said that with a tensile strength comparable to steel but corrosion-resistant, carbon fiber strands require less maintenance over time. The result is bridges that last longer and save taxpayers money on life-cycle maintenance costs.
“Rusting of steel elements is the leading cause of deterioration in our bridges. Since carbon fiber is non-corrosive, we are eliminating that potential for damage,” said MDOT Chief Bridge Engineer Matt Chynoweth. “Using a material that will not corrode is a real game-changer.”
The department said it is deploying the carbon fiber strategically on higher-volume routes. Two bridges are currently being built with carbon fiber reinforced beams, MDOT said, as part of a modernization project on I-94 in Detroit. The fiber is also being used in the southbound I-75 span over the Sexton-Kilfoil Drain in Detroit.
While carbon fiber elements are as much as three to four times as expensive as comparable steel elements, the research indicates that they may prove to be cheaper in the long run because they last much longer than steel.
“We’ve calculated the ‘break-even point’ to be about 22 years based on life cycle maintenance,” Chynoweth said. “But since the data points only go back about 20 years, this is a theoretical estimate.”