Rusting steel structures are a problem. Rusting steel reinforcing bars inside concrete structures are an even bigger problem.
“The trick, of course, is that you can’t see the damage,” says mechanical and mechatronics engineering faculty member Carolyn Hansson. “So you don’t know which structure is in trouble until it’s too late.”
Carolyn studies the corrosion of steel inside concrete, from the rebar in parking garages to the post-tension cabling in bridges. Corrosion “is a multi-billion-dollar problem,” says Carolyn. “In the U.S., the direct cost of repairing highway bridge corrosion is $8.3 billion annually.” Indirect costs can easily be 10 times that – and those are the costs for bridges alone.
Carolyn studies techniques for measuring the amount of corrosion, including electrical metres that look for rust indirectly by measuring the current in the iron and acoustic monitors that listen for the ping of cables snapping within bridges. She is also studying rust-resistant reinforcing materials, such as stainless steel.
In 2009 Carolyn, who has received major awards for her work, became a fellow of the Royal Society of Canada. Election to the RSC is the highest Canadian honour a scholar can achieve in the fields of arts, humanities and sciences.