Smart Design, Strategic Construction
Smart Design, Strategic Construction
Combining intelligent city building with strategic concrete placing technology
Vaughan, a city north of Toronto, is rapidly creating a downtown and an identity for the first time, thanks to the development of the Vaughan Metropolitan Centre (VMC), and Expo City, a residential community at the heart of the project. For construction of the project’s first high rise, Putzmeister truck-mounted concrete boom pumps from the Amherst Concrete Pumping (Amherst) fleet in Toronto are placing concrete from the ground up in as strategic a method as the design of the city building itself.
Development of the VMC will set a new standard for intelligent growth when the Spadina subway extension makes its first stop in Vaughan during 2015. In preparation for this mass transit, the city’s long-range master plan got underway with the July 2012 groundbreaking of Expo City, which will include five condominium towers and is the starting point in transforming more than 442 acres (179 hectares) into a sustainable, pedestrian-friendly urban center with retail space and luxury residences, as well as trails and parks.
Expo 1 Logistics
Destined to set the tone for future development, Expo City is deemed an intelligent approach toward city building with an influx of office, entertainment and other amenities expected to follow. Expo City is a signature project for developer and construction manager, the Vaughan-based Cortel Group (Cortel), and begins with Expo 1, a 37-story residential condominium tower with three underground levels, a six-floor podium beside it and an eco-friendly design.
When soil testing revealed that a concrete raft slab was needed for added stability of the tower, Amherst was called upon for its expertise and equipment to orchestrate a non-stop concrete pour under a tight time constraint. The pumping company, celebrating 50 years in business this year, had the experience to handle the logistical feat, having placed concrete for tunnels, roads and bridges, as well as commercial and residential construction, over the past five decades.
“It’s all about service and performance; so we needed to ensure we organized all the logistics to be in perfect sync with each other, as well as select the right equipment to get the job done as efficiently as possible,” said George Battaglini, Amherst logistics manager. Battaglini, along with Expo City construction site supervisor Ashraf Makary, played critical roles in the coordination leading up to and throughout the evening of the pour to ensure its success.
To create the 82-foot by 135-foot (25m x 41m) slab at a six-foot (1.8m) thickness, Amherst selected three Putzmeister truck-mounted concrete boom pumps, a brand new 42Z-Meter and two 63Z-Meters, to accomplish the feat. The trio of machines pumped 2,367 cubic yards (1,810 cubic meters) of concrete in four-and-a-half hours, with Battaglini noting that “the speed of this pour had to set a record within the Greater Toronto area.”
Cortel project manager Anthony Cortellucci concurs, “The pour was one of the largest and fastest raft slab pours ever accomplished in the Canadian Province of Ontario. It was the talk of the trade for months.”
To achieve the exceptionally fast pace, equipment setup was crucial. With just one ramp into the 40-foot (12m) deep hole, ready mix truck entry and exit would be limited; so only one pump, the 42Z-Meter, set up in the excavation next to the slab. Its 136' 10" (42m) boom provided plenty of reach, and its five-section Multi-Z boom provided the necessary maneuverability to access all areas of the pour without relocating the machine.
An upper-level parking lot on the edge of the excavation offered the other location for pump setup; however, about 200 feet (60m) of boom reach was still needed to access the pour below. Thanks to modern technology, the development of longer reaching boom pumps has evolved to avoid the labor-intensive task of dragging extra delivery line and achieve greater pumping efficiency. Therefore, Amherst, recognizing early on that a larger boom would be beneficial for customers, purchased their first 63Z in 2007, followed by the same model size purchased in 2012. This pair of pumps would solve the reach problem.
The two larger pumps set up next to each other?one with the truck cab nosed to the hole’s edge and the other set up parallel to the hole. With this setup, the staging of ready mix trucks didn’t interfere with each other while the necessary reach was still achieved.
“Although we needed the two 63Zs for their long reach, their .20H pump cells get a lot of credit for the amazing speed of the pour. Nothing can touch the high output of these Putzmeister pump cells,” said Doug Hunt, Amherst boom pump operator of 10 years. The BSF 63Z.20H can deliver up to 260 yd3/hr (200m3/hr) outputs.
"The pump’s eleven-inch (280mm) cylinders kept concrete flowing at an extremely fast pace,” said Hunt. “I set my control dial to 10, the farthest it goes, and I was pumping over 300 bar without any sign of the engine bogging down.”
“And with the longer stroke of the pump, I was operating the pump wide open without even the slightest bit of boom bounce,” adds Hunt. “I know the crew below appreciated the smooth concrete flow, as they were already working hard to keep up with the fast pace; plus, we were even topping off the slab while pumping at maximum output.”
Dufferin Concrete of Toronto dispatched a 30 MPa 20mm aggregate with four-inch (100 mm) slump and minimal plasticizers. The concrete was deemed a ‘good mix’ by Toronto standards, which is a relative term, as the area is notorious for extremely harsh mixes, many of which are almost unpumpable. However, Amherst’s pumps have tackled the area’s tough-to-pump mixes before, most recently the mix for the new subway headed to Vaughan, which consisted of a large one-and-a-half inch (40mm) crushed stone with a low water-cement ratio from 55 to 83 MPa; so they could easily pump this mix at top speed.
To prepare for the unknown, a 52Z-Meter and a second 42Z-Meter concrete boom pump were also on site as backup, and both machines had their booms unfolded and ready to use if needed. However, no technical issues were encountered.
Six boom pump operators were also on site, two per machine?one operating the radio remote controls and one at the hopper backing up and directing the ready mix trucks to maintain a constant and rapid rate, as well as provide operator backup and support.
“The boom pump operators really should be recognized for their hard work and dedication,” says Battaglini, who lists the six as Doug Hunt, Brad Ferrill, Jared Burns, Brad Gun, Shane Baker and Derek Tensen.
“It turned out to be the perfect pour,” notes Battaglini. “Our highly experienced operators and Putzmeister concrete pumps performed flawlessly. Plus, the ready mix supplier precisely timed the mixer trucks from three different batch plants so we had a fast and steady supply of concrete as well as the exact amount of the mix needed to the end.”
Cortellucci adds, “The concrete pumps placed concrete at an incredible volume, everyone meshed together and no setbacks or delays were encountered. Even with a steady rain that night, we still finished about three hours earlier than planned.”
No Crane Downtime
Concrete placement for the raft slab and six-story podium in front of the first tower is complete. The 37-story tower is progressing upward with the 63Z-Meter as the workhorse. As of late July, the boom pump was placing concrete on the ninth floor.
“There was a low overhead crane that we had to contend with on the floor pours, but with the 63Z’s Z-Fold boom design and five boom sections, I could maneuver the boom under the crane so we never had to shut down the crane to place concrete,” says Hunt. “If it weren’t for the versatile design of this Putzmeister boom, it would have meant costly crane downtime and a slower pumping process.”
Each floor is formed in one section with the boom pump placing 235 cubic yards (180m³) per floor, one floor is completed each week.
Ultimately, Expo City will be surrounded by lush greenery and water reservoirs, and it will feature the latest in rainwater management systems. Over an acre of green rooftops will capture the excess water that will then be treated and funneled back into the community’s natural eco-system. Another unique feature of Expo 1 is that the building is positioned on an 18-degree angle to ensure maximum sun exposure in each of the 337 units and unobstructed views for each residential tower. Set for completion in 2014, Expo 1 units range from 527 to 2,088 square feet (50 to 195m²) and priced from the mid-$200,000s to over one million dollars.
Excavation of Expo 2, the second 37-story high rise to be located next to Expo 1 and share similar amenities, is underway as of summer 2013.
Putzmeister America, Inc. manufactures a complete line of truck-mounted concrete boom pumps, separate placing booms, truck-mounted telescopic belt conveyors, ready mix trucks and trailer-mounted concrete pumps as well as mortar, grout, shotcrete, plaster and fireproofing pumps and mixers, industrial pumps, tunneling machinery and pipeline systems. Some of the industry’s best known brands, such as Telebelt®, Thom-Katt®, and Tommy Gun®, are part of the Putzmeister America family. The company’s workforce is dedicated to hands-on customer support and advancing the industry in design and technical innovation.
Architect: AJ TREGEBOV Architects—Vaughan, Ontario
Builder and Developer: Cortel Group—Vaughan, Ontario
Formwork Contractor: Yukon Cor Corporation—Vaughan, Ontario
Ready Mix Supplier: Dufferin Concrete, a division of Holcim (Canada) Inc.—Toronto, Ontario
Concrete Placing Contractor: Amherst Concrete Pumping, Inc.—Toronto, Ontario
Equipment: Putzmeister truck-mounted concrete boom pumps: 42Z-Meter (2), 52Z-Meter (1) and 63Z-Meter (2)