While repairing expansion joints on the 16th Avenue NW overpass across Crowchild Trail in Calgary, the concrete contractor saved time and construction costs by using Planitop 15 form-and-pour concrete repair mortar.
Crowchild Trail (Alberta Highway 1A)—so named in 1971 in honor of David Crowchild, Chief of the Tsuu T'ina Nation from 1946 to 1953—is a principal expressway running through the west side of Calgary, Alberta. The Trans-Canada Highway (Alberta Highway 1), also known as 16th Avenue NW where it runs through the city, passes over Crowchild Trail north of the Bow River near McMahon Stadium.
Roughly 30,000 cars a day travel over 16th Avenue NW, while Crowchild Trail supports the passage of up to 65,000 cars daily. When the overpass needed repairs, the major issue that the contractor and his crew faced in the bridge rehab work was to turn over drive lanes as fast as possible to reduce the inconvenience to motorists commuting; 16th Avenue is the primary highway that spans Calgary east to west and can be quite busy in early-morning rush hour.
The contractor was looking for alternatives to using High-Performance Concrete (HPC). When Graham Infrastructure started the project using HPC, it was faced with the major issue of travel time of the concrete in ready-mix trucks to the jobsite and the limited amount of time that crews had to empty the truck. The extra expense of small-load delivery charges also added to the job costs. MAPEI offered the contractor a better alternative
Because of the amount of forming that was used to complete the repairs, the contractor needed a form and pour product that would not set up too fast so that the crews could mix and deliver material in a timely fashion. Most of the repairs were all form-and-pour repairs, so MAPEI recommended Planitop 15 form-and-pour concrete repair mortar.
Graham Infrastructure gave the following summary regarding the use of Planitop 15 on the overpass reconstruction:
- “Flexibility: We were on a very tight timeframe on this job and were paying substantial site occupancy fees, so every day gained on the schedule was a big savings to us. When we were replacing expansion joints on this project, as soon as they were ready to be poured, we did it immediately with Planitop 15. This saved us having to worry about getting concrete booked perfectly for each pour and the delays associated with that. We were able to pour one at a time instead of waiting for all the joints to be ready at the same time. Ready-mix concrete has a 5-cubic meter minimum load requirement for HPC, and because of the small areas we were pouring, a lot of concrete—at least half the load—would have been wasted each time. Also, because of gaining strength quickly, we were able to put traffic on the expansion joints and move to our next phase a day or two quicker than if we would have used concrete."
- “Wet-cure time: The owner had a seven-day wet-cure requirement for HPC, but because of the recommended cure time of three days for this product, we were able to save four days on every pour. With the dynamics of this rehab job, opening and closing lanes, and moving to the next stage as quickly as possible, this time savings meant we were weeks ahead of schedule at the end of the job."
Recent additions to the Crowchild Trail overpass will include a pedestrian bridge. The new bridge is part of the City-led project, Glenmore Trail Widening and Interchange Improvements program.