Opening Opportunities in Infrastructure

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.” Since composite rebar is significantly lighter than steel rebar, it takes fewer trucks to transport the bars (or bridge components made with composite rebar) to the jobsite. That reduces CO2 emissions. Contractors can use smaller, less costly cranes to lift composite bridge components into place, and they’re easier and safer for construction workers to handle. FRP Bridge Innovations State DOTs looking to assess the performance of composite materials in bridges have a wide range of old and new projects from which they can choose. Marshall Composite Technologies used its C-BAR® rebar in 1996 to reinforce the concrete deck of Buffalo Creek Bridge in West Virginia. It was the first time FRP rebar had been used for a vehicular bridge in the U.S., and the composite deck is still performing well. GFRP rebar is typically made through a pultrusion process that cures the material as it is pulled out of the equipment in a straight line. Marshall Composite Technologies has developed an innovative technology that skips that pultrusion curing stage. “It allows us to go at four to five times the speed of traditional pultrusion, because we’re not limited by having to cure inside a mold,” explains Tom Ohnstad, director of engineering. “After we have formed the rebar with the ribs, we can go straight into the final oven and cure it, or we can bend it and then put it in an oven and cure it.” Moving from a continuous process to a batch process has enabled the company to provide rebar in the custom curved or bent shapes that construction projects often require. Creative Pultrusions, part of the Creative Composites Group, used pultruded composites to build the world’s largest FRP, clear-span, pedestrian bridge during the last two years. The 152-foot long, box truss structure, part of the company’s E.T. Techtonics line, connects two sections of a 22-mile trail built on an abandoned rail bed in Bermuda. Creative Pultrusions designed and engineered the composite structure, manufactured samples of the bridge’s unique connections and components and then sent them to the University of Miami and West Virginia University for testing. Once the design was finalized, technicians at Creative Pultrusions pultruded the bridge in sections no longer than 39 feet, since they had to fit into shipping containers for the journey to Bermuda. Prior to shipping, the company assembled and tested the bridge on its own site to ensure it met the strength and stiffness requirements. That initial build also ensured that the crane in Bermuda could handle lifting the bridge into place. The bridge owner participated in this trial construction, which was fortunate because no one from Creative Composites Group could travel to Bermuda to oversee construction during the pandemic. Final construction of the bridge in Bermuda, which took place during December 2020, went smoothly and quickly. Using prefabricated components provides a safety and cost-saving advantage that DOTs should consider when they look at the total cost of bridge projects, says Dustin Troutman, director of marketing and product development. “The longer you’re on a bridge or a job site, the higher the risk of accidents.” Material Improvements AIT has built 30 bridges across the country using its GArch™ composite bridge system, which includes curved FRP tubular elements and FRP decking. In late 2020, the company introduced a new technology, GBeam™ composite tub girders, to construct the Grist Mill Bridge in Maine. AIT worked with the University of Maine and the state DOT to develop the GBeams, which incorporate carbon fiber and glass fiber in the bottom flange and glass fiber in the top and can be fabricated up to 120 feet. Grist Mill Bridge’s eight, 75-foot-long composite girders are replacements for steel girders. Because of the GBeams’ lighter weight, the contractor was able to use a much smaller crane to lift them into place. In addition, the contractor put two of the GBeams together and pre-installed all the utilities that had to run under the bridge in the channel between them. It’s much safer to have the work done on shore rather than having workers installing the necessary piping and wiring while working over the river. Although the GBeam technology is more expensive today than steel girders, Sweeney expects it will become more cost competitive over time through efficiencies in processes and manufacturing. He also notes that the composites supply chain has been much less volatile than the steel supply chain, which has seen increasing costs and long delivery times. Another material that could impact the composite bridge industry is rebar made with basalt. The basalt material derives from lava rock that is melted down and formed into fiber strands, which can then be chopped. “Within the composites’ family, E-CR glass fiber remains the most used fiber type because of its availability and low cost. However, the interest in basalt fibers has been growing since their physical properties exceed those of glass and the cost difference is marginal,” says Alvaro Ruiz Emparanza, director of engineering and business development at Mafic. “In terms of performance, basalt has higher tensile strength and modulus of elasticity than E-CR glass, but its properties are definitely not as high as carbon fiber.” He notes that basalt fiber might be particularly useful in pre-stressed composite structures. Basalt fiber for rebar is slightly more expensive than glass fiber but significantly cheaper than carbon fiber. With the price of glass going up, however, basalt is becoming more competitive. Emparanza says that the basalt industry doesn’t want to compete against glass and carbon fiber but wants to be part of the total solution that the composites industry can offer. From Poles to Platforms Some composites manufacturers are pursuing opportunities in other types of infrastructure where resiliency is of primary concern. “The composites industry is well positioned in terms of structures that can withstand the wind, rain and weather,” says Scott Reeve, president of Creative Composites Group’s, Composite Advantage Division. (Reeve also chairs ACMA’s Transportation Structure Committee.) In Puerto Rico, the Virgin Islands and Florida, utility companies have been installing GFRP telephone poles, which remain standing in the hurricane winds that bring down wooden poles. West Coast utilities companies have expressed interest in fiberglass-reinforced poles designed to withstand wildfires. Many utilities are now replacing wooden cross arms on utility poles with composite cross arms. They like the light weight, resilience and non-conductive properties of the composite materials, and the fact that one FRP cross arm can replace two wooden ones. “We’ve had several projects related to the critical infrastructure for our energy grid. Protective FRP-reinforced composite walls can help prevent transformer damage from high winds, fire, ballistic or blast threats, but are electrically inert so there’s no need to ground them,” says Ohnstad. Composites are also proving useful in keeping U.S. waterways open and navigable. Reeve says that protective fences (fenders) made from composite materials installed in the water around structures like bridge piers can withstand damage from boats and barges. Because they are non-corrosive, composites are being used more frequently in seawalls as well. “Another big area is the changeover of rail station platforms from concrete to fiberglass,” Reeve adds. At transit agency stations in the Northeast corridor, the chemicals used for de-icing the train platforms have quickly degraded the concrete. With GFRP platforms, the de-icing chemicals work effectively but cause no damage. Construction speed is especially important for this application. The platforms are so light that Creative Composites Group can prefabricate large sections and install them at night when the trains aren’t running as frequently as during the daytime. This minimizes train delays and reduces inconvenience to rail passengers. Some jurisdictions are using composite materials for pedestrian walkways on bridges. “Agencies are putting in bigger, lighter sidewalks on the sides of bridges. Instead of a little two-to-three-foot concrete curb, you may be adding 10-foot-wide sidewalks,” Reeve says. Obstacles to Adoption One problem that could slow the adoption of composites for infrastructure work is the method that government owners use to evaluate project bids. “In general, the procurement process is focused on the low bidder on the acquisition side. In the past, the longer life benefits have not been considered, and that’s an area where composite materials excel in terms of corrosion resistance, low maintenance and long life,” says Reeve. Although some states have begun changing this approach, the Biden administration’s stated commitment to climate change, sustainability and resiliency could speed up the process. “As the administration goes to work, implementing the programs that are going to be used to administer these [infrastructure] dollars, they will be putting that overlay on those programs to achieve maximum benefit in those policy areas,” says Nadeau. He believes that pressure will also come from the public, especially young people who want to see governments and industry adopt more sustainable practices. If infrastructure owners get serious about reducing carbon emissions “they’re going to see how much more carbon they're putting into the atmosphere, whenever they specify a steel bridge, or especially a concrete bridge as compared to an FRP bridge,” says Troutman. “We've done enough homework to know that our carbon footprint and embodied energy is going to be significantly less than that of aluminum, steel and concrete.” To get the maximum benefit from infrastructure spending, the composites industry must make a concerted effort to reach out to infrastructure owners, engineers, designers and other decision makers to educate them about the sustainability benefits of composite materials. “I believe that the major players in the composite industry have not taken this seriously; they have not devoted the level of attention to innovation in this arena like they've done for other markets,” says Nanni. “Look at what’s happened with composites in the aviation industry over the course of 30 years, and then look what’s been done in the composite industry for construction. The difference is day and night.” Part of the problem is that there is no easy way to identify and reach out to the decision makers among building owners and infrastructure agencies. Unlike aerospace, where there are just a few large companies, the key people in building and infrastructure design and construction are spread out among all the states and among various owners/agencies within those states. Once they connect with the right people, composite manufacturers also need to understand that it will take time for government bureaucracies to make changes, but that their efforts today will pay dividends over time. “In a lot of cases we're doing presentations to Department of Transportation engineers or to rail agency engineers. And that’s not a sales call. It’s not going to amount to a PO tomorrow. It is part of the educational process on what FRP composites can do,” says Reeve. “They look at this stuff, and they want to vet it and make sure it’s good. And then finally – and it may take years – they say, ‘Hey, this is the right place for me to use FRP composites.’” The composites industry must continue to impart its important message to infrastructure stakeholders. “Composites in general have a lot to do toward the sustainability or resilience of our infrastructure,” says Emparanza. “Sadly, we know that climate change is happening, with more severe weather events and the sea level rising. So, we need to act not only for the present but also for the future.” Mary Lou Jay is a freelance writer based in Timonium, Md. Email comments to mljay@comcast.net.