SEPARATE PLACING BOOM AND O-ELEVATION FRAME COMBINE FOR SPEED ON HYATT CONSTRUCTION 2004

Since April of 2003, Denver-based Brundage-Bone has supplied a KVM 39 separate placing boom and an innovative application of a standard Schwing mounting system to the site of the new, $369 million bond-funded Hyatt Hotel. Previously teamed on the construction of the Colorado Convention Center Expansion in downtown Denver, the concrete pumper and general contractor Hensel-Phelps Construction Co., Greeley, CO moved one block across the street to work on the 38-story hotel.

While there are many options for separate placing booms, the most common practice is to mount the boom on a mast that extends down through the floors of the structure. The general contractor asked Brundage-Bone Assistant Manager Chris Clark to provided a KVM 39-meter separate placing boom combined with a zero-elevation frame system to help meet the projected October 2005 construction deadline.

“Schwing pioneered this technology,” says Clark, “The mounting options with these placing booms are endless, and that versatility allowed us to execute construction in this way. It’s been very successful.”

In addition to their pumping services, Brundage-Bone is the largest Schwing authorized concrete pump dealer in the world. The contractor also supplies parts and service to Schwing customers from locations throughout the United States. Clark says the company purchased the boom in 2002.

With a vertical and horizontal reach of 114 feet, the KVM 39 is the longest separate placing boom that can be mounted at zero elevation. Mounted on top of an elevator core form, the placing boom base becomes part of the framework and rides with the system. An electric and hydraulic jacking system raises the form system, allowing the placing boom to move upwards as decks are completed. The placing boom and framing system weigh in at 250,000 pounds, while the half- million pound self-climbing form system rolls along I-beams at the upper most deck. Reinforced structural beams handle the heavy load.

Over the last several months, the KVM 39 separate placing boom has been completing the elevator core, columns, and decks of the predominantly concrete structure.

Hensel-Phelps Area Superintendent Rebecca Brown appreciates the simplicity behind the mounting system. “Because it is actually a part of the forming system, it rides right with us. We don’t tie up the crane removing and relocating the boom. We’re using the placing boom on a daily basis and it hasn’t hindered the carpentry, finishing or other labor schedules. Our four-day cycle is completely possible with the boom being used almost daily.”

The benefit to the zero-elevation frame is two-fold. The boom remains in the same relative position throughout the project, with no need for removal and remounting to other locations. With extensive horizontal and vertical reach, the KVM 39 covers a wide area from one location, while on-site cranes remain free to complete other work.

The new Hyatt covers approximately one city block in downtown Denver, surrounded by four one-way streets running counterclockwise, with a popular station for the area’s lightrail system nearby. Since the beginning of the project, Brundage-Bone has utilized a 32 XL concrete boom pump on grade to feed the placing boom. Because of the tight urban work site, ready-mix truck access has been limited to one or two trucks at a time, and concrete delivery starts at between two and three in the morning.

“It’s a temporary set-up,” says Clark. “Eventually we’ll have a more permanent set-up area near the hotel’s loading dock. At that time, we’ll probably bring in a Schwing 8000 line pump. Then we’ll really be able to hit it.” Contractors will continue to pour in night and early AM hours as construction progresses.

Ready-mix supplier LaFarge North America, and internationally renowned provider of construction materials, has provided a wide spectrum of concrete mixes to the site. Matt Riebe, Sales Manager with LaFarge’s Denver branch, says as the buildings height increases, production numbers will also climb. “As of now we’re staging trucks as they need them, and we’ve been able to supply them what they need with minimal difficulty. Once we’re out of this tight spot, we’ll be able to maximize production.”

The concrete building will provide 1,100 rooms and serve as Denver’s “headquarter hotel.” The completed structure will offer 85,000 square feet of meeting space including two ballrooms, measuring 30,000 square feet and 15,000 square feet. At total of three levels of parking have already been installed, all below grade. Hyatt officials hope the hotel will be operational near the end of 2005.