Currently, contractors repair highway columns by adding more concrete and steel to the structure. Sheikh's alternative, which uses glass or carbon fibre instead of steel, provides up to five times the strength of steel, helping structures meet and exceed the requirements of the current building codes. "It will extend the life of highways and give people precious extra seconds to get to safety during an earthquake," he says. "We think cities everywhere, particularly in earthquake zones, will benefit from this technique."
The procedure itself, which uses epoxy and a large, flexible sheet of glass or carbon fibres as the reinforcing material, is not new, Sheikh notes. However, his team is the first in North America to devise specialized retrofitting schemes for concrete structures. Sheikh and his team wrapped the materials around the highway columns and they strengthened bridge culverts with fibres - specifically, on Highways 401, 404 and the QEW - all without requiring any traffic-snarling road closures. The technique is detailed in the July 2002 issue of Engineering Structures.
Additional Contact Information: Professor Shamim Sheikh, Department of Civil Engineering, 416-978-3671, sheikh@civ.utoronto.ca
Engineering Structures