On the Perimeter: Major Winnipeg project brings concrete solution to longstanding bottleneck
On-Site Magazine - Canada's Construction Magazine - Article by David Kennedy April 23, 2019
Infrastructure rarely ages gracefully. When there isn’t much elegance to the original design, 20 or 30 years can be particularly cruel.
The junction of a pair of provincial trunk highways northeast of Winnipeg was just such a case.
For years, the intersection of PTH 59 and PTH 101, commonly known as the Perimeter Highway, relied on a pair of traffic lights to smooth out a crossroads that never quite lined up. Drivers looping around Winnipeg’s ring road heading east, for instance, needed to come to a complete stop, turn right, briefly drive south and then turn left, just to continue in the same direction.
The antiquated set-up often slowed traffic to a crawl. Meanwhile, ever-increasing volume on the two roads, now totalling some 70,000 vehicles each day, only worsened the bottleneck.
“That’s one of the busiest intersections in the province,” says Diana Nicholson, a project manager with Nelson River Construction Inc. “There’s lot of heavy truck traffic on the Perimeter and the communities just outside the city have really grown, so there’s a lot of people commuting into the city.”
In the warmer months, cottage traffic heading north along PTH 59, or Lagimodière Boulevard, only compounded the issue.
Overhauling the juncture was a tall order, but armed with a budget of $204 million, the construction team was up to the task. After just over three years of construction, a modern interchange – that includes 11 bridges and incorporates more than 70,000 cubic metres of concrete – began a phased reopening last fall. That’s not to say there weren’t a long list of challenges along the way.
THE DREADED FULL STOP
Like other aging pieces of infrastructure across the country, the major problem at PTH 59/101 required a major fix. “This interchange was kind of an anomaly,” Nicholson says. “The magnitude of this project was massive, relatively speaking, for Manitoba.” Plans for the new interchange would see the obstructive pair of traffic lights bulldozed and replaced with a slightly modified cloverleaf. With the full stops exchanged for a series of ramps, vehicles could keep moving in all directions.
To add longevity to the interchange, the province also opted to pave with concrete as opposed to asphalt. “Manitoba typically uses concrete pavements in high traffic volume scenarios,” according to a provincial spokesperson. “Concrete was used at the PTH 59 and 101 interchange project as this interchange sees some of the highest traffic volumes in the province.”
Flatiron Construction Canada Ltd. served as the general contractor for the project, and subcontracted the paving portion of the job to Nelson River. The Manitoba builder was responsible for about 240,000 square metres of concrete roadway, plus numerous stretches of asphalt pavement on the road’s shoulders and certain bridge decks.
Earth started moving in summer 2015, but with unaccommodating, wet weather through much of the first two construction seasons, crews laying the groundwork faced an uphill battle. Manitoba has a very heavy kind of clay soil,” Nicholson says, adding that the mud work, which fell under Flatiron’s scope of work, was tough going with all the precipitation. The importance of the intersection to the overall Winnipeg-area road network also posed a major obstacle.
“The biggest issues involved staging the concrete construction in a manner that allowed traffic to continuously move through the project site,” a provincial spokesperson acknowledges. “This meant construction was broken down into many small parts.”
Throughout construction, crews were required to keep four lanes of PTH 59 and two lanes of PTH 101 open at all times.
The stipulation was necessary to ensure commuters and truck traffic could still make their way in and around the city, but it created headaches for the roadbuilders.
Before the initial demolition work could even begin, for instance, crews had to lay a significant amount of temporary pavement for an east-west detour. All told, the project involved some 15 separate phases and no shortage of traffic switches that confused and aggravated drivers.
A CONDENSED SCHEDULE
Following the weather-related delays that hampered much of the prep work in the first two seasons, the majority of the concrete paving needed to be put on hold.
It was very compressed,” Nicholson says. ”We ended up having like two years of concrete paving in one season.”
Concrete and aggregates supplier Lafarge stepped onto the project during its second year. The company transported concrete to the site during the 2016 and 2017 seasons from its ready-mix plant on Dawson Road, about 10 kilometres southwest of the interchange, but the concrete trucks weren’t exempt from the gridlock around the construction site. They often became tied up in traffic jams as concrete crews sat idle waiting to pour.
This changed the following spring when an on-site batch plant came to the rescue.
Lafarge moved an Axiom RMX200 to the job for the final season, substantially cutting round-trip times to keep up with the demanding schedule that had been tightened into 2018 by the early delays.
"This not only allowed us to provide superior service to the project but also benefited the rest of our business by lowering the truck demand required for the pours due to the short turnaround to our on-site plany." says Jason Ryz, sales manager for ready mix concrete at Lafarge Winnipeg. "We were regularly supplying 1,000 cublc metre pours or more daily, servicing teh pours with 10 trucks on average."
In addition to the ready-mix for the paving and bridge decks, Lafarge's Aggregates division supplied the project with 250,000 tonnes of road base, while its Precast unit built bridge girders.
As supplies flooded onto the site throughout 2018 construction season, Nelson River ran two concrete paving crews of more than a dozen workers each to stay on schedule. A pair of base crews of similar sizes worked ahead, "desperately trying to keep ahead of the concrete guys.", Nicholson says. "Without those guys working their asses off," there's no way the road would have been finished on time, she adds.
NOT THE TYPICAL MANITOBA JOB
Along with the large scale of the project, the interchange design, particularly when it came to pourng the concrete, was complex.
Between non-standard lane widths and types of steel Nelson River wasn't accustomed to using on other Manitoba Infrastructure projects, Nicholson says her team had its work cut out for it.
"We weren't able to just have a big open space where we were able to lay gravel and concrete very efficiently," she says. "It was done in these funny shapes all over the place. We had to constantly move our paver widths, which takes quite a lot of time."
To make up some of that lost time in the final year, the company rented a Gomaco GP3 to complement its other equipment. The machine made it easier to accomodate different widths and "made a difference" in finishing some of the smaller pieces, Nicholson says. As the days got shorter last fall and Winnipeg's weather turned colder, the paving teams had to stay on the job when they'd normally have packed it in for the season.
"Winnipeg's climate, with its short construction seaosn, also proved challenging," a provincial spokesperson says. "Long work hours and temperature control means...were used to increase production.
As the pavers rolled forward on particularly cold days, workers were sent back to cover freshly-poured concrete with insulating tarps designed to keep some of the heat in the concrete. This, while months earlier crews had been forced to add ice to the conrete during high-heat days because the tight schedule didn't allow for any lost time.
Lafarge was also forced to change up their mix due to the weather. Ryz points to a Winnipeg stipulation that requires no fly ash be used in concrete when the temperature drops below -5C. When a chill set in, the concrete mixes contained stright concrete powder.
In the end though, even the temperamental Winnipeg weather couldn't keep the construction team, which numbered about 600 accross all aspects of the project, from wrapping up the work. The interchange began re-opening to traffic in stages in September - though some finer details remain on the docket for the spring. Nelson River, for instance, still has diamond grinding to do on about 80,000 square meters of concrete pavement, as well as some asphalt paving on certain smaller sections.
As of last fall, Manitoba remained under budget on the project, having spent approximately $250 million on construction, plus land acquisition. It had set aside $275 million for the job initially.
The province is also planning for the future. Currently, PTH 101 spans four lanes through the interchange, with two in each direction. The realigment put the infrastructure in place to expand to six lanes when necessary.
The nearly-complete interchange erases a one-time blot on the Perimeter, while the road's concrete surface and enhanced design are expected to provide it with the durability to age a little more gracefully than the clunky intersection it repalced.