Portage Bridge Rehabilitation, Ottawa, ON

MS-D1 X

Location:
Ottawa, Ontario
Contractor:
David S. Laflamme Construction
Quantity:
185 m3 (242 yd3)
Consultant:
Genivar
Product:
MS-D1 X
Completion:
Winter 2011

3.3.3x Case History - Portage Bridge, Image 1

The Portage Bridge is a busy, six-lane, inter-provincial road that crosses the Ottawa River and joins downtown Ottawa in Ontario to Gatineau in Québec. Built by the National Capital Commission and opened in 1973, this bridge is now a crucial passage way for many commuters who travel between the two provinces. The bridge consists of six traffic lanes, two bicycle lanes and a pedestrian walkway.

Genivar, a leading Canadian consulting firm, was hired to verify the extent of structural damage that resulted from years of exposure to de-icing salts and freeze-thaw cycles. The project was released for tender in May of 2010 and awarded in June of 2010, to David S. Laflamme Construction of Ottawa. The original specifications called for pressure grouting on small patches below the bridge. However once the concrete removal process began, it became evident that the extent of deteriorated concrete was much more significant than previously anticipated.

After examining the site conditions, logistics, and allowable time frame, it was determined that the shotcrete process would be the best option for placing the concrete. Special platforms were built between the steel girders so that work could be completed from below the bridge. The platform allowed the shotcrete and chipping crews to access the area, and also prevented concrete debris or rebound from entering the river below. The shotcrete work was sub-contracted to Coaster Concrete of Gatineau, Québec, who overcame cold weather challenges by using MS-D1 X.

The flexibility of the shotcrete process offered a number of advantages over traditional form-and pump applications. Coaster crews were able to set-up the shotcrete machine on either approach to the bridge, which allowed the material to be conveyed over long distances (up to 400 ft), to the nozzlemen below. The accelerated set-time and rapid strength gain offered by MS-D1 X, allowed the National Capital Commission to keep the bridge open, even during the shooting process.

MS-D1 X is a silica fume enhanced, air-entrained mix that provides excellent resistance to salt-scaling and freeze-thaw cycling. The silica fume also reduces permeability values and provides added protection against any future corrosion of the reinforcing steel. The area repaired exceeded 904 m2, with an average thickness of 120 mm, and resulted in the use of approximately 410 bags (1,000 kg each) of MS-D1 X.

King Packaged Materials company is a proud member of the American Shotcrete Association (ASA)!

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King Packaged Materials Company is a proud member of the Tunnelling Association of Canada (TAC)!

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KING's Engineering Services Team offers a variety of specification documents. E-Mail engineeringservices@kpmindustries.com to request these resources.

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