Two Towers, Two Booms Mean High Production On Miami Condo 2006
From Concretepumping
Miami residents will be seeing double as the twin towers of 500 Brickell climb 44 stories to join the growing condo market in Miami. Perched on top of an 11 story parking structure, the towers will represent one of the largest concrete structures in Miami at 1.5 million square feet of 8-inch slab. The pumping contractor is Cherokee Pumping Company, with headquarters in Hampton, GA and an office in Pompano Beach, north of Miami. Concrete contractor, Baker Construction, Monroe, OH is handling the job from their Medley, FL office for General Contractors Facchina-McGaughan, LLC with offices in Fort Lauderdale and Washington, DC.
Two foundation slabs (2,400 and 2,800 cu. yds) were pumped by Cherokee earlier this year using their truck pump-mounted Schwing 58, 39 and 32 meter booms. All models are equipped with all-hydraulic Generation 3 pump kits with open loop design that incorporates long stroking pumping cylinders. The net result is fewer strokes for less wear and smooth, controlled output. “The ready-mix plant couldn’t keep up with the pumps,” according to Ray Pisaneschi, project manager for Baker.
As garage construction continued, Cherokee’s S58SX was able to reach deep into the decks with its Overhead Roll and Fold Boom that allows the first section to be angled back and the other sections to be precisely maneuvered to a maximum reach of 187-feet ten-inches. Schwing’s patented Super X outriggers with their curved shape allows them to telescope out and around jobsite obstructions – a long boom advantage in an urban setting, The Super X outriggers on the 58 enjoy the smallest front spread in its class at 29’2” maximizing horizontal reach. As construction schedules were accelerated, a separate placing boom and BP 8800 were added at the fourth floor. Two masts were positioned in pre-engineered openings in the existing decks and secured with wedges in floor frames.
A Schwing 8800 concrete pump joined the separate placing boom and will remain on-site for the duration of the project. The 562 hp pump is capable of 152 yards per hour and 3524 psi on the concrete. Assisting in this accelerated production rate is the High Pressure Rock Valve with double-shifting cylinder. It is feeding two mast locations through one line up the center of the parking structure with a diversion valve to send concrete to the active mast. In this way, crews are able to fly the 32-meter boom with four-pin quick disconnect when crews are stripping one-half of the deck forms and be ready to pour the second half in less than an hour. Baker crews poured each 50,000 square foot garage floor in 6-8 days.
Because of Florida ground conditions, a 10,000 square foot section has been left out of the garage. Differential settling of the two towers could occur so the garage structure will be tied together after the towers reach the 22nd floor. “We will use the S58SX to pour that middle portion,” Pisaneschi reports.
With the towers climbing independently after the 11th floor of the garage, two booms are profiled against the blue sky of Florida. “Because the cranes can’t reach far enough between the two towers, we would have had to set the boom on the ground after pouring the east tower and pick it up and mount it on the west tower, “ said Pete Hernann, Cherokee superintendent on site, “And that just doesn’t cut it in this fast paced market.”
Instead the two booms are climbing together utilizing the tower cranes only to hoist the masts up as the building climbs. “We finish a pour on one tower and ten minutes later we are pumping on the other tower, “Hernann says, “My most experienced man is on the ground with the pump and we use local operators to run the booms.” The 14,500 square foot tower floors are easily handled by the 93-foot reach of the 32-meter placing booms.
Vertical members on the all-concrete structures require a 12,000 psi mix that is being handled by the 8800. “The walls consume 170 yards per floor, the columns 500 yards and the decks 400 yards. We are achieving production goals pouring four times per week to complete a floor for each tower, “Hernann reports, “I think we will leave the pump on the rod side for volume all the way to the top.”
At the end of each day cleanout is handled with compressed air discharging back into a ready-mix truck. “Clean-out of the Rock Valve is a simple proposition,” reports Hernann, “And there is not that much waste.”
Aluminum gang panel forms are flown from the ground and the decks are truss forms. “Cherokee is making this project as easy as it comes. The equipment is working well and we are on schedule for an April 2007 completion, “Pisaneschi says.
