New Champlain Bridge could use ultra-high performance concrete
Infrastructure Canada says normal concrete can corrode in 15 years, ultra-high performance lasts for 70 years
The consortium behind the new Champlain Bridge project is considering the use of a new ultra-high performance concrete (UHPC) for some parts of the bridge.
"We're looking at a selective, precise application of this ultra-high performance concrete for the surface of the bridge and also for the joints," said Daniel Genest, with the Signature on the Saint-Laurent consortium.
Ultra-high performance concrete (UHPC) contains small steel fibres, which are supposed to help slow the development of cracks and, as a result, corrosion caused by traffic and temperature changes.
Genest said UHPC comes with certain risks if it's used without discretion because it's relatively untested in Canada.
"There's always danger introducing a new technology into a high-risk project like the new Champlain Bridge," he said.
"There hasn't been widespread use [of UHPC] in Canada yet."
It will take up to 70-80 years for salt and water to reach the steel and corrosion to start, whereas with normal concrete, the salt could reach the steel after 15 years.- Zoubir Lounis, Concrete structures group at the National Research Council of Canada
The more tried and true high-performance concrete will still be used for the majority of the bridge.
Some engineers in Montreal told Radio-Canada this week that the new, UHPC concrete would be a better choice for the entire bridge given its durability.
National Research Council touts benefits of UHPC
A 2010 report published on the National Research Council of Canada's website outlines the benefits of high and ultra-high performance concrete.
"It will take up to 70 - 80 years for salt and water to reach the steel and corrosion to start, whereas with normal concrete, the salt could reach the steel after 15 years," stated Zoubir Lounis, leader of the concrete structures group at the NRC Institute for Research in Construction, in the article.
Infrastructure Canada does require construction on the bridge to use a minimum of high performance concrete.
Anything beyond that is left to the discretion of the consortium.