TALLEST TOWER IN EDMONTON GETS THE SEPARATE PLACING BOOM TREATMENT
Citing the overwhelming efficiency of a separate placing boom and pump, Noremac Industries Ltd., Edmonton is pumping the tallest building in their home town. The Epcor Tower will rise 28-stories above a city that hasn’t seen a downtown office tower constructed in more than 20 years. “The city had never seen a separate placing boom on a local building before this, but the decision to use one was easy when you consider the efficiency,” explains Cameron Currah, founder of Noremac, “The general contractor asked for the separate placing boom on this project and we were glad to accommodate them.”
Before the separate placing boom was erected onsite the company used four of their 30 Schwing boom pumps to place a 4,000 cubic meter base mat for the tower. In September 2008, the company put their KVM 55, KVM 39X, S 41 SX and KVM 36 to work on filling the 8-foot thick foundation. “The concrete contractor specified LaFarge’s Agilia Foundation mix which is a self consolidating concrete that went through our pumps very easily and we finished the pour in 18 hours, “Scott Bertolozzi, Noremac special projects manager, explained, “We had a lot more output potential but the truck mixers couldn’t cycle any faster.”
The rectangular footprint of the 614,000 square foot building made it impractical to boom the concrete from the edge of the excavation without multiple set-ups. “When we decided to use the separate placing boom, Schwing explained the advantages of setting it up early in the project, “ Bertolozzi remarked, “So the first use of a separate placing boom in Edmonton was actually below grade.” The 4-section SPB 37 boom with 120-feet of reach and 112 mm pipeline was placed atop an octagonal mast which was supported by a cross frame bolted to the foundation slab. The Roll and Fold boom utilizes a 238-degree folding tip section for maximum versatility. The low 13,090 pound weight of the unit and the design of the six-meter, bolt together modular mast sections allowed the company to free stand the boom without a counterbalance.
As Noremac began pumping the underground parking decks and columns, crews poured around the small 41” square opening required for the mast. As more levels of the underground parking were completed, Noremac crews added additional sections. The 37-meter boom can free stand to 50-feet and the company’s SPB 28 (93-feet horizontal reach) can be elevated to 70-feet on a freestanding mast. The bolt together modular mast sections have built in brackets for attaching pipeline and ladders.
“We are pumping at a steady rate of 60 cubic meters per hour which suits the finishers and the project schedule, “according to Bertolozzi. The company chose a Schwing SP 4800 to feed the boom. The twin-cylinder all-hydraulic stationary pump is positioned 130-feet from the vertical standpipe that feeds the boom. The 2020-5 pumpkit can apply up to 1508 psi on the concrete and place up to 81 cubic meters per hour. A Deutz 443 horsepower engine powers the unit.
The building is expected to receive a silver LEEDS certification for low energy, water and resource use. Its design will include an east-west orientation for a sunny southern exposure, high-performance glass to reduce heat loss and gain, and low-flow water fixtures. “Epcor is a publicly owned energy corporation so they were particularly concerned with sustainability, water and energy conservation, “explained Bertolozzi, “The Schwing pump’s fuel efficiency and reduced water usage for clean-up of the Rock Valve fit right in with the project’s green approach.”
When the construction progress reached grade level it was time to transition the mast into floor frames to take it to the top. Noremac chose to use a self-climbing system from the manufacturer. Two frames on separate levels are used to support the boom. “The self-climbing system is simple and doesn’t require crane time which allows material delivery to the other trades to proceed uninterrupted,” according to Bertolozzi, “We are using dedicated crews to jack the mast and the flexibility to raise the boom only as high as we have to has paid off.”
The first three levels of the tower are dedicated to office/retail with 20-foot floor spacing. Standard floor spacing for the office portion from the fourth to the 28th floor is 14-feet. “Because the octagonal system provides mounting holes at 20-inch intervals, we can raise the mast and head section to the optimum height above the deck to get maximum utilization from the boom, “Bertolozzi explained.
The company added hose sections to reach the farthest corners of the office/retail floors but can now pump directly through the end hose for the smaller floors that will complete the building. The finishing crews from concrete contractor Pagnotta Industries, Edmonton place one-half of a floor in an eight-hour shift. Mix design is a plasticized 3500 MPA concrete.
After each pour, concrete is reversed in the pipeline and discharged into a ready-mix truck for recycling. The company uses a diversion valve and “candy cane” to elevate the returned ready-mix to charging hopper height. “Being the first time we had worked with a separate placing boom, we had some issues discharging into the ready-mix trucks during clean-out,” explained Currah, “I had the opportunity to meet with some other pumpers at a Schwing Customer Advisory Committee meeting and they helped us overcome those issues.”
When Epcor Tower is completed in late 2011, it will be the main headquarters for EPCOR Utilities Inc. which builds, owns and/or operates power plants, electrical transmission and distribution networks, water and wastewater treatment facilities and infrastructure in Canada and the U.S. More than 1,300 employees will occupy the office space which will feature balconies on all sides of the structure.
Noremac began as a concrete contractor in 1984. In 1987, Noremac purchased its first concrete pump to compliment its existing placing and finishing division. The company began specializing in concrete pumping in 1995 and today Noremac Industries Ltd. covers the largest geographic region of any Canadian concrete pumping contractor completing projects from the western border of Ontario to British Columbia. Noremac Industries Ltd. pumps concrete for both the residential and industrial/commercial industries. Projects range from home patios and house walls to airports, bridges, high-rises, grain elevators and mining sites.
The Epcor building is located on the downtown Station Lands development site which has been zoned for additional residential and commercial towers. “Based on the efficiency of the pump and boom and its visibility on this project, I would say we are ideally positioned for future high-rise pumping using this method,” states Currah.
Project: Epcor Tower, Edmonton, Canada
Owner: Qualico Developments, Edmonton
Architects: Kasian Architecture Interior Design and Planning, Calgary and Edmonton
General Contractor: Ledcor Construction Ltd., Vancouver, British Columbia
Concrete Contractor: Pagnotta Industries, Edmonton
Concrete Pumping Contractor: Noremac Industries Ltd., Edmonton
Equipment: Schwing KVM 55, S 41 SX, KVM 39X, and KVM 36X. Schwing SPB 37 with octagonal mast mounting.