Infrastructure protectionConcrete solutions to aging, structurally deficient bridges

According to the Pennsylvania Department of Transportation (PennDOT), the state leads the nation in the number of bridges classified as “structurally deficient.” This is probably not a surprise to most residents who have done any driving throughout the commonwealth. The state’s more than 25,000 state-owned bridges are aging — their average age is over fifty years — and in need of repair. Civil engineer Farshad Rajabipour and his colleagues are working on solutions.

Rajabipour, together with Aleksandra Radlinska and Gordon Warn, all Penn State civil engineering faculty, are researching methods for enhancing the maintenance and durability of civil infrastructure — including anything made of concrete, from bridges to roads to buildings.

“We are looking at improved maintenance practices, specifically how to reduce cost while improving safety and longevity,” says Rajabipour. “Conventionally, we have not done much preventive care of our infrastructure, until we see potholes or more significant signs of damage and failure. Then we have to do repairs out of urgency. The better approach is one of preventive maintenance, which will save money, reduce traffic, and improve the longevity of bridges and roads. It’s similar to health care for people — preventive measures can make you healthier and extend your life.”

Rajabipour explains that steel rebar corrosion and concrete cracking, among other factors, contribute to infrastructure degradation over time. He and his students work to understand and predict how those damages happen so they can be prevented.

“Let’s say you have a bridge that is five years old,” says Rajabipour. “That bridge has a certain bill of health — a certain extent of damage — and we want to predict what its health will be ten to twenty years down the road. Should we do any maintenance treatment now, and what should that treatment include to have a better, safer, and longer-lasting bridge in the future?”