CUSTOM HPC MIXTURES FOR CHALLENGING BRIDGE DESIGN

The Confederation Bridge, spanning the Northumberland Strait between Prince Edward Island (PEI) and mainland Canada, represents one of the largest public works projects in the history of Canada. Most of the components, including the main girders and support piers, were fabricated on land at one of two precast facilities situated either side of the bridge. Seven different types of concrete were required to provide various combinations of the following properties: - low permeability to chloride ions; - high early-strength (for post-tensioning); - high resistance to ice abrasion; - low heat rise in massive sections; - underwater placement (tremie concrete); - slipforming; - high density for ballast; - resistant to freezing and thawing, and seawater attack (all exposed concrete); - pumping (most concrete); - high flow in congested areas; - controlled set. This article discusses the concrete producer's role in supplying high-performance concrete (HPC) to meet the demanding requirements of both the technical specification and the production schedule of this prestigious project.