Terry BourqueEdmonton, Canada, is no ordinary Canadian city. The capital of Alberta, Edmonton is the northernmost city in North America with a population of more than one million. It is also the staging ground for the tar sands oil project and diamond mining taking place in Alberta. This “Gateway to the North” has experienced quite a bit of growth over the last decade as a result of these geological undertakings. In preparation for continued expansion, the province’s Department of Transportation has taken steps to make traffic flow more readily.
One of those projects was the construction of the Rabbit Hill Road Bridge, a stainless steel-girded overpass on the 216 Beltway, Anthony Henday Drive. Also known as the Ring Road, the beltway has been under construction for nearly a decade and all new construction, including the Rabbit Hill Road Bridge, was designed to uphold the strict guidelines of Alberta Transportation, which includes building with an aim of a 100-year lifetime.
Warding off corrosion
In a city as far north as Edmonton, that means paying special attention to the elements. The city’s location on flat prairie land just northeast of the Canadian Rockies means winters can be cold and harsh, with temperatures averaging around –10° Celsius in January and snow and ice a part of life for nearly half the year. To withstand the wear and tear that roadways face due to de-icing salts, Outokumpu has recommended the use of duplex grade because of its corrosion resistance; in a city like Edmonton, where de-icing salts are in frequent use, this corrosion resistance is a must.
Short turnaround window
Likewise, long winters in Edmonton posed another problem during the bridge’s construction: a short summer means a short window in which the bridge could be put up. Deliveries of rebar to the fabricator needed to take place with enough time to ensure the construction was completed before the first snow fall.
The short time frame planned for the bridge’s girders to be installed over the course of less than a month in 2011. Beginning in May 2011, construction was completed by autumn, paving the way for a lot more traffic. In fact, the 20-year projection has daily vehicle loads doubling by 2030 – from 40,000 vehicles per day to 80,000. A load the duplex stainless steel can definitely handle.