Putzmeister Placing Booms, a Cure for Challenging Concrete Pour at Hospital in Vermont February 2004

STURTEVANT, Wis. (Feb. 2 , 2004) – Putzmeister concrete pumping equipment is playing a key role in a $356 million Renaissance expansion project at The Fletcher Allen Health Care complex in Burlington, Vt.

Fletcher Allen's plan to build an Ambulatory Care Center and Education and Conference Center in cooperation with the University of Vermont will bring together patient care, education and research into an integrated health sciences campus, marking what officials are calling a “renaissance” for the academic medical center. The Education and Conference Center will physically link Fletcher Allen with the university. A patient access center, an underground parking garage and a central heating-air conditioning plant are other components of the project.

Macomber/Barton Malow, a joint venture of Macomber Builders and Construction, Boston, and Barton Mallow Design/Construction Services, Southfield, Mich. , is the general contractor. Another joint venture, Pizzagalli, Griswold, Ireland, in Burlington is handling the concrete portion of the job that ultimately will involve placing approximately 63,000 cubic yards. More than one- third of that total will be used in building the 1,250-vehicle parking structure.

Challenges typically arise during construction projects. On this job, the greatest challenge proved to be in building the four-level garage, mainly because once on-grade access was removed, no route existed to get concrete to the center of what would become the first floor.

This area measured 40 feet deep and 330 feet square. A pair of Putzmeister placing booms situated on two, specially mounted 50-foot towers, offered the solution.

Precision Concrete Pumping Inc., Albany , N.Y. , supplied the placing booms and towers. J.P. Perron, president and owner of Precision, said, “Compared to other brands and alternatives, our Putzmeister equipment was the most logical choice for the contractor. First, the brand new booms provided more reach than others in the area. Second, the booms did not need counterweight so it wasn't cumbersome to move. And finally, we offered a special mounting configuration on a ballasted-base cross, which was ideal for the application.”

Each base cross, in the shape of an “X”, rests on the finished concrete floor. Thirty-two tons of ballast or counterweight atop the base provides stability.

“With the ballasted base, the contractor has the flexibility to erect anywhere on site without pouring 20 yards of concrete at different setup locations,” Perron said. “And at an estimated cost of about $12,000 per footing location, it saves them a ton of money.”

Jon Pizzagalli, project engineer for Pizzagalli, Griswold, Ireland, said, “The special ballasted base means a significant cost savings. No time and labor is required to form up and pour foundations that would later be abandoned or patched over. We also don't have to deal with excavation spoils, where we'd have to dig below the floor of the garage and fly the dirt out by crane. The weighted bases make a lot more sense than the other alternatives we considered.”

One half of the 370,000-square-foot garage is being built from the lowest level to the highest level. Then, placing booms will be shifted and the process repeated to construct the remaining half.

Each level is divided into three separate, 14,000-square-foot pours. Each half of the garage will require 15 such pours. Two Putzmeister 34-Meter separate placing booms that reach 111 feet horizontally are being used in these pours. The pumps place an average of 50 yards an hour. Griswold Concrete and SD Ireland, also of Burlington, are supplying the ready-mix. It takes about five days to place each deck.

Consuming 24,000 yards of concrete, the structure will include the 34-inch-wide supporting beams poured on site. Three of the concrete garage decks are each 9 inches thick while the top deck is even thicker – 16 inches – to permit eventual grass seeding and landscape plantings atop the structure.

“Without the placing booms, we basically couldn't do this job,” Pizzagalli said. “We would have had to fly in every load of concrete with a crane and bucket and that would have taken months longer to accomplish. When you have the right tool for the right application, as was the case with the placing boom and special ballasted base, it can prove invaluable in getting the job done efficiently.”

The Renaissance project began in the fall of 2001. Completion is scheduled for 2005.

JOB SPECS: Owner: Fletcher Allen Health Care and the University of Vermont, Burlington, Vt. General contractor: Macomber/Barton Malow, a joint venture Concrete contractor: Pizzagalli, Griswold, Ireland, a joint venture Ready-mix supplier: Griswold Concrete and SD Ireland, Burlington , Vt. Equipment supplier: Precision Concrete Pumping, Inc., Albany, N.Y. Equipment: Two Putzmeister 34-Meter separate placing booms, two Putzmeister 50-foot towers and two ballasted mounting bases