A decade ago, conversations about infrastructure mainly revolved around the need for additional funding to repair it. But those discussions have evolved, increasingly emphasizing the need for sustainability and resiliency in projects that involve building or rehabilitating the nation’s roads, bridges, ports, power grid and more.
The composites industry can provide the sustainable solutions that states seek. With increased funding, like that proposed in the $1.2 trillion infrastructure bill (see sidebar), state agencies would have more money and more opportunities to test innovative technologies and construction techniques.
“There are so many examples around the country, whether it’s bridges or reinforced building structures, where utilization of composite innovation has been demonstrated to be effective,” says Greg Nadeau, chair and CEO of Infrastructure Ventures. “The huge investment in the infrastructure bill for bridges over and above the regular allocation does present an opportunity for states to use those funds to expand the use and understanding of these alternative materials. They’re not experimental; they’re proven.”
Building Better Bridges
Composite materials are already being used to build more resilient bridges. Coastal states and northern states that use road salt during the winter have seen their bridges decay due to the corrosion of the steel in reinforced concrete and pre-stressed concrete structures. Using non-corrosive materials like composite rebar can reduce the amount of money that state Departments of Transportation (DOTs) must spend on bridge maintenance and repair.
“Ordinarily a conventional bridge rated at [a lifetime of] 75 years has to be substantially addressed over a period of 40 or 50 years. With a non-corrosive at the base of your material selection, you extend life and you reduce long-term lifecycle costs,” says Nadeau. “You are building a bridge that you literally won’t have to worry about generationally, and that’s an extraordinary opportunity.”
There are other cost savings as well. “The composition of the concrete can be different if we have a material that does not corrode. For example, we don’t have to use corrosion inhibitors, which can cost about $50 per cubic yard,” says Antonio Nanni, professor and chair of the Department of Civil and Architectural Engineering at the University of Miami.
Bridges built with composite materials can be designed with more streamlined support structures. “With concrete, you’re spending a lot of your money and resources to build that bridge to hold itself up, not on its function, which is to carry traffic,” says Ken Sweeney, president and chief engineer at Advanced Infrastructure Technologies (AIT). “If you can lighten that up and have a higher strength-to-weight ratio, it’s a huge benefit; the construction is less costly.”