CORVALLIS - Engineers at Oregon State University are trying to develop improved systems to identify the bridges in the state most in need of repair, the cause of their problem and the techniques that could best be used to reinforce them with safe, cost-effective technologies.
They want to know exactly why these bridges are cracking and what can be done about it.
Field tests are now being conducted near Newburg, Ore., with monitoring equipment that can tell precisely what types of stresses a bridge is enduring as heavy trucks and other traffic roll over it and how the bridge is reacting to it. One of the bridges being studied will soon get repaired, and similar approaches may be used on many others around the state.
"You cannot find a major route in Oregon traveling north-south or east-west that doesn't have aging, reinforced concrete bridges with these potential problems," said Chris Higgins, an OSU assistant professor of civil, construction and environmental engineering. "It's a major problem that the Oregon legislature just budgeted $440 million to address, and we're trying to make sure this work is done as efficiently and effectively as possible."
OSU has a two-year, $160,000 grant from the Oregon Department of Transportation to work on these issues. Besides the testing and monitoring technology, OSU civil engineers will also try to identify the technologies, some of them fairly new, that can most effectively solve the problems of individual bridges.
One innovative technology using fiber-reinforced polymers, which was tested at OSU several years ago, is now being more widely used across the nation, Higgins said. Other approaches include the use of external steel plates for reinforcement; installation of additional reinforcing bars inside concrete; and use of "post tensioning" with steel bars that can compress cracks in bridges to increase the strength of the beams.