New Super-Strong Concrete Could Fix Nation's Bridge Problems

Students at the University of Connecticut have begun testing a new "super" concrete - a mixture of chemicals and fiber that’s two to three times stronger than traditional concrete.

📅   Mon April 18, 2016 - National Edition


Students at the University of Connecticut have begun testing a new
Students at the University of Connecticut have begun testing a new "super" concrete - a mixture of chemicals and fiber that’s two to three times stronger than traditional concrete.

NPR is reporting that students at the University of Connecticut have begun testing a new "super" concrete - a mixture of chemicals and fiber that's two to three times stronger than traditional concrete.

Standing in a laboratory packed with various scientific instruments, University of Connecticut engineering professor Arash Zaghi gestured to three steel beams, modest in appearance where they sit under the large and brightly-painted hydraulic-powered machine capable of applying weights of up to 275 tons.

Engineers refer to these beams as girders, a key component in bridge support. These three girders, modeled after a bridge in the Hartford area, were pressed under the lab's hydraulic load machine until their point of failure.

But the beams themselves aren't the most important piece in the experiment. What's notable is the cast of concrete around one of the beams, which increased the steel's load capacity when the machine was pushing over hundreds of tons of weight into it. Zaghi said this super-strong and durable concrete could transform the way engineers across the nation approach bridge repair.

Many of Connecticut's bridges are nearing the end of their useful lives: about a quarter of the bridges in the state have been rated as functionally obsolete, and ten percent are deemed structurally deficient. Officials say these bridges are still safe to drive on, but there's high demand for a quick and cost-effective bridge preservation method.

One problem aging bridges face is corrosion from the elements and salt from the roads. Corrosion often occurs at the end of beams in the superstructure of the bridge -- the part that supports car traffic. Engineers usually use steel plates to patch up bridges. But that approach can be expensive and time-consuming, yielding lane closures and congestion.

Another problem with traditional infrastructure repair is that engineers and maintenance crews are still using methods that they used a half-century ago, Zaghi said.

“You don't commute in 40-year-old cars,” Zaghi said. “The ones today are entirely different. But our infrastructure is similar to the way we were doing it 40 to 50 years ago.”

“You don't commute in 40-year-old cars. But our infrastructure is similar to the way we were doing it 40 to 50 years ago.”

So Zaghi, in collaboration with the Connecticut Department of Transportation, is leading a research team that's testing the tenacity of a new “super” concrete -- a mixture of chemicals and fiber that's two to three times stronger than traditional concrete.

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