Engineers at the University of Toronto have developed "smart" concrete structures that could reduce the amount of road closures caused by bridge repairs.
Researchers at U of T's Institute for Aerospace Studies (UTIAS) are experimenting with a "smart" structure on the Leslie Street bridge in northern Toronto. The project, which has been developed over the past two years, involves lining the bridge's columns with fibre-optic sensors and wrapping them with advanced composite materials -- light-weight synthetic that covers the structure like plastic sandwich wrap. "The wrap lessens the deterioration and holds the structure together, while the sensors precisely measure possible corrosion that may be occurring underneath," says Rod Tennyson, head of the Fibre Optic Sensing (FOS) Laboratory at UTIAS. "All of this means less road maintenance in general and ultimately less road closures."
The fibre-optic sensors are the same kind of hair-thin cables used in the telecommunications industry except they are wrapped around or embedded in concrete structures. A short section of the cable is stripped of its protective coating and treated with high-intensity ultra-violet beams to create a sensing region that detects corrosion from within. The experimental sensors are unique in their 10-foot length -- most sensors are closer to an inch in length -- and in their wrap-around application.
The researchers would ultimately like to install smart structures across the country and to develop remote systems that would allow monitoring by centrally located computers, rather than the time and expense involved in sending work crews for on-site inspections.
The UTIAS laboratory is funded by Intelligent Sensing for Innovative Structures (ISIS) Canada, a federal Networks of Centres of Excellence program headquartered at the University of Manitoba.