Short span bridges traditionally are cast in concrete -- and plastic usually forms the fuel tanks in a car's undercarriage.
But they do not always have to be made from those materials, steelmakers say. The steel industry boasts it has come up with new designs for making cheaper bridges and more environmentally friendly fuel tanks with the metal that is forged in mills across Northwest Indiana.
"Our research and development has resulted in the deployment of some exciting lightweight materials," said Larry Kavanagh, president of the Steel Market Development Institute, an industry-led effort to boost business for steel.
Steelmakers have been working in recent years to expand into new markets beyond the cars, appliances, buildings and cans much of the steel made in East Chicago, Gary and Burns Harbor goes into. They have been designing new products to drive up demand.
A Czech operation of global steelmaker ArcelorMittal recently developed new safety barriers aimed at preventing serious motorcycle crashes. The metal barriers have a lower guard strip that prevent motorcyclists from sliding underneath in a phenomenon that is known as under-riding.
The Steel Market Development Institute, whose financial backers include ArcelorMittal and U.S. Steel, recently has devised new designs for steel gas tanks and short span bridges, which range in size between 20 feet and 140 feet. Short span bridges span creeks and roads, and are a fraction of the size of behemoths like Hammond's Nine Span Bridge.
Steel gas tanks already can be found in local dealership lots, including in the Ford Mustang, Chevrolet Volt, the Mercedes-Benz M 450h luxury SUV hybrid vehicle and the Lexus RX 450h advanced hybrid electric crossover vehicle. Steel is impermeable to hydrocarbons and has been especially popular at helping automakers meet partial zero emissions vehicle standards in California and other states.
Steel fuel tanks also are in vogue with advance hybrid vehicles, which need highly rigid tanks because of the vapor that builds up in the carbon canister when they are being powered by electricity. Chevrolet has used hot-dip tin-zinc coated steel for the fuel tank in the Volt since 2011.
The new steel bridges could be coming soon to local roads. The Short Span Steel Bridge Alliance, an arm of the Steel Market Development Institute, has come up with an Internet-based tool that lets engineers design customized steel bridges in three steps and less than five minutes.
An Iowa community recently replaced a 66-year-old bridge with a wider one made with galvanized steel beams and galvanized rebar. Steel industry representatives recently pitched the short span steel bridges at an annual bridge conference for county engineers in West Lafayette.
The potential market could be huge, since more than half of the nation's 605,000 bridges fall under the short span range of less than 140 feet, said Robert Willis, the Steel Market Development Institute's vice president of Construction. The exact size of the market is hard to quantify because it depends on how much state and local governments set aside for bridge maintenance, but engineers have determined about a quarter of the bridges nationally are structurally deficient or functionally obsolete.
"It is not unrealistic to anticipate that over 75,000 short span bridges bridges will need to be repaired or replaced in the near future," Willis said. "If sufficient funding were available, this market segment could account for 2 million tons of steel over the next five years. This would include steel plate girders, wide flange shapes, corrugated steel pipe and plate, sheet and H-piles, and miscellaneous sheet, bars and bolts."
A typical bridge would consume 35 to 55 tons of steel.
"The first short span bridge was installed in Jesup, Iowa," Kavanagh said. "That bodes well for this technology. We match the modular design and ease of installation at about 15 percent to 19 percent less cost than precast concrete. It's an excellent growth opportunity, especially as bridges get repaired and widened to service traffic needs."