Next time you see a crew working on a bridge, think of Kansas University.

A team of researchers at KU’s civil, environmental and architectural engineering departments is working on a long-term project to determine how to make concrete bridge decks more durable.

Replacing and maintaining bridge decks cost billions of dollars annually nationwide, said David Darwin, a distinguished professor with the engineering department who is leading the research effort.

And there are less apparent costs.

“There is also an enormous cost to the public in slowdowns on the highways and increases in accidents,” Darwin said.

The research project is focusing on how to protect bridges better from corrosion caused by the sun, rain and de-icing salts. And the research team is studying ways to build bridges and the development of less corrosive de-icing substances.

The research is expected to last about 10 more years, and its current $1.5 million price tag is being funded by the National Science Foundation, Kansas Department of Transportation and several other state and industry groups, Darwin said.

KU researchers will soon put their findings to the test by working with KDOT to construct several new bridges and replace some old ones in northeast Kansas. The researchers then will monitor the durability of the spans.

In laboratories at Learned Hall, researchers compress long-term environmental conditions over a short period of time by bombarding concrete and rebar with heat, rain and salts.

In bridge decks, the aging process starts as cracks form allowing water to contact the rebar.

“Cracking provides an avenue for the salt to get down to the rebar very rapidly,” Darwin said. “The water freezes and expands, causing more damage.”

The researchers also are studying the reliability and cost-effectiveness of different types of concrete mixes and steels. So far, they have found some forms of more durable construction materials that cost more initially but, because of their lasting qualities, may be less expensive in the long run.

As part of the research, Darwin recently completed a $50,000 study for South Dakota transportation officials that compared the durability of a new microcomposite rebar with an epoxy-coated rebar. The study determined epoxy-coated rebar lasted longer without needing repair.

“Our effort is aimed at looking at ways to increase the durability of reinforced bridge decks,” Darwin said.