The stronger bridges of Madison County

When the Highway 151 bypass around

opens later this year, vehicles travelling northbound will cross DeNeveu Creek on a bridge like no other in the country.

Externally, the bridge looks identical to its adjacent twin. However, internally, the concrete deck is reinforced with a fibre-reinforced polymer (FRP) grid system that could replace conventional epoxy-coated reinforcing bars (rebars) inside future bridges.

University of Wisconsin-Madison Professor of Civil and Environmental Engineering Larry Bank, Associate Professor Mike Oliva and graduate students David Jacoboson and Mack Conachen developed the system, which is said to have several advantages over the steel rebars bridge-builders currently use.

"The steel reinforcing bar in the concrete deck corrodes," explained Bank. "That corrosion causes cracking of the concrete, the concrete then chips off and you get potholes and all of those problems that people don't like on bridges."

Because it is non-metallic, the fibre-reinforced polymer material won't corrode, giving it the durability to last at least 75 years, said Bank. "Most bridge decks will only last somewhere between 30 and 40 years before they have to be replaced," he said.