It’s just the shot in the arm that Winnipeg’s North Main Street area has been crying out for.
Once, the area between Logan and Higgins Avenues was teeming with activity as the northern end of the bustling downtown during Winnipeg’s infancy. So vibrant was it that Winnipeg was known as The Chicago of the North. The train station on Higgins discharged thousands of immigrants bound for points west, and who shared the wooden sidewalks with the likes of Charlie Chaplin (who stopped regularly in Winnipeg on the vaudeville circuit, and it was from Winnipeg that he wrote the letter to his brother, telling him that he had decided to give “moving pictures” a shot).
The past few decades, however, had not been kind to the area, which gradually fell into decay, and became the hub of many of Winnipeg’s social problems. Since the late ’90s, however, there has been a concerted effort to revitalize the Main Street “strip”, and the new Winnipeg Regional Health Authority (WRHA) complex at Main and Logan has become a key component of this rebirth.
The new five-storey, 80,000-square-foot (7430 m2) building — with adjacent six-level parkade — includes a community health clinic, several community services such as public health and home-care services and about a third of the authority’s administrative offices.
Precast products were employed generously throughout the two structures; the office building with 8-inch (203 mm) and 12-inch (305 mm) hollow core slabs on a steel structural frame — utilized primarily for cost but also for speed of construction — and the parkade built entirely with pre-cast, incorporating 12-inch (305 mm) wide, pre-topped Double Ts, centre Vista Walls, exterior columns and architectural spandrels.
The Double Ts are cast with a four-inch (100 mm) flange — as opposed to the more typical two-inch (50 mm) flange – for the driving surface, so that additional concrete didn’t have to be poured on top of the Double Ts, which were then caulked at the joints, providing the seal for the parking deck.
Low permeable concrete with fly ash provided a durable driving surface, while the 60-by 12-foot (18.3 m x 3.7 m) Double Ts provided interior column free parking and the exposed aggregate spandrels and columns provided attractive exterior aesthetics.
For Ted LeBlond, Practice Leader with architectural firm Stantec Consultants, the versatility of precast was a major advantage of incorporating it into the design. “We were designing for a very tight site, and we also had a very tight design and construction schedule so bringing in precast elements made (the whole process) much easier,” explains LeBlond. “On the planning side, we were able to design the building to a certain point, and then put it out for tender pretty quickly, with the knowledge that once it was tendered, the successful precast contractor would be able to design their portion of the work, and get it up to the site in fairly quick order to allow construction to stay on schedule; precast was ideal for that.”
Beyond that, says LeBlond, the great look of precast made it a natural choice. “The spandrel panels that we used had an exposed aggregate finish with a colour additive, and you don’t see that very often anymore. We wanted to try to tie the parkade aesthetically to the office building, and precast allowed us to do that; not only did we get the finish, but the quality control of that finish was much better using precast than it ever could be with poured-in-place concrete. The quality control at the precast plant allowed us to achieve that exposed aggregate finish we were looking for much easier than we would ave been able to do on site.”
Guy Bernuy, Senior Sales Engineer for Armtec (formerly Con-Force Structures), points out that space was limited on site, necessitating accommodations on both the design and construction sides; the single-helix parkade ramp, for example, was designed with a six per cent ramp slope, instead of the standard five per cent grade.
More significant was the challenge of managing logistics due to space limitations on and around the site, and the fact that it was adjacent to the major Main Street traffic artery. “Because of the heavy weights of the precast components,” explains Bernuy, “a 300-tonne mobile crane was required, and that crane required careful maneuvering to get it into the site, and maneuver once on-site. The majority of the precast erection was accomplished with the crane inside the footprint of the parkade, and the remainder was done from the adjoining back lane and an adjoining property. Because the site is on a major traffic thoroughfare, the truckloads had to be coordinated carefully, but that ultimately worked out quite well.”
Precast was an advantage in managing the limited space since it was precast fabricated off site, then brought to the site for installation, which not only sped up the work, but was easier than the poured in place option – which would have required building form-work and pouring floors in a limited space.
Speed of precast erection proved another advantage because the design-construction process needed to happen in a relatively short time frame, and Bernuy emphasizes that precast allowed for the speedy assembly of the building before the arrival of another famous Winnipeg winter.
Those attributes mean that the use of precast in future projects will only increase. “As designers,” concludes LeBlond, “we’re finding that precast is much more cost-effective and versatile than it was before, so we’ll be looking at it for other building types more than we have in the past.”
Owner: Winnipeg Regional Health Authority, Corporate Office
Architect: Stantec Consultants
Structural Engineer: Stantec Consultants