New Champlain Bridge could use ultra-high performance concrete

The consortium behindthe new Champlain Bridge project isconsideringthe use of anewultra-high performance concrete (UHPC)for some parts of the bridge.

"We'relooking at a selective, precise application of this ultra-high performance concrete for the surface of the bridge and also for the joints," saidDanielGenest,withthe Signature on the Saint-Laurentconsortium.

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 UHPCcomes with certain risks if it's used without discretionbecause it's relatively untested in Canada.

"There's always danger introducing a new technology into a high-risk project like the new ChamplainBridge," he said.

"There hasn't been widespread use [ofUHPC] in Canada yet."

It will take up to 70-80 years for salt and waterto reach the steel and corrosion to start,whereas with normal concrete, the salt could reach the steel after 15 years.- ZoubirLounis, 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, UHPCconcrete 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 websiteoutlinesthe 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," statedZoubirLounis, leader of the concrete structures group at the NRC Institute for Research in Construction, in the article.

Infrastructure Canada does require construction on the bridgeto use a minimum ofhigh performance concrete.

Anything beyond that is left to the discretion of the consortium.