New Style Placing Booms Provide High-Flying Production At Intel Site 2006
Brundage-Bone Concrete Pumping, operating from their Southwest Division headquarters in Phoenix, Arizona, has been on the site of the Intel plant in Chandler, AZ since the early 90s. Demand for Intel processors has required continuous expansion so plant and office workers at the site continue occupying new expansions as construction continues. Since 2005, general contractor Hoffman Construction Company, Portland, Oregon and Brundage-Bone have concentrated their efforts on the most recent expansion known as FAB 32.
To expedite construction and determine what equipment is most appropriate to pour an estimated 75,000 total yards of concrete, the 350-foot wide by 1600-foot long FAB 32 site was divided in half, lengthwise. On the north side, two of Brundage-Bone’s Schwing S 61 SX booms are completing slab, wall and column pours on a daily basis. These booms are supplemented by their latest model – the S 41 SX – depending on reach requirements.
A total 780 identical columns on this part of the site measure 36 feet tall. Their height matched with a tight interior rebar configuration made the traditional method of handling column pours impractical on the FAB 32 site. In addition, the general contractor elected to utilize an Self-Consolidating Concrete (SCC) mix design, making vibration unnecessary. The combination of these factors called for the columns to be pumped using the bottom-up method of placement. “The crane and bucket method would have been impossible,” said Brundage-Bone Phoenix Branch Manager Randy Waterman.
The column forms are outfitted with one inlet at the bottom and one located approximately half way up the length of the column. Both of the ports are equipped with shut-off valves. A Hoffman laborer, utilizing a safety harness, climbs the height of the form to monitor the concrete level. Once the column is filled half way, crews cut off concrete flow and move on to the next column in the series. Crews proceed with this method over a series of five to six columns, and then return to top off each column in the series.
On the north side of the Intel site, the 61-meter booms are utilizing their full 184-foot horizontal reach to complete 18 pours on the sub-floor level, 10 slab on grade pours and 10 waffle deck pours.
As work proceeds on column construction on the north side, Hoffman and Brundage-Bone turned their attention to the challenges posed on the south side of the site. Site restrictions made boom pump access difficult, which encouraged the pumper to explore the advantages afforded by a separate placing boom system. Brundage-Bone took delivery on a KVM 39 X with detachable placing boom and one 39-meter separate placing boom in 2005. Fresh from the factory in White Bear, MN, both feature the newest Generation 2 separate placing boom technology from Schwing America.
The Generation 2 placing boom system used at Intel consists of three components: the adaptor, the powerpack/reservoir and the placing boom. Because the boom is separate from the powerpack/reservoir, the picking weight of 13,200 lbs. is the lightest for its length providing the contractor with flexibility regarding crane size and location. The ease of mounting the boom with the 4-pin quick detach system makes it easy for Brundage-Bone to fly the boom from the three-axle truck to its mast in minutes. In addition to the four pins, eight quick disconnect hydraulic hoses need to be removed to fly the boom. This allows the KVM 39X to be quickly reattached to the truck and used on conventional pours when the boom is not needed at Intel.
For mounting the boom on site, the combination cross frame at Intel can be configured into a zero-elevation, free-standing or ballasted frame. On the FAB 32 site, the Generation 2 boom was mounted in a zero-elevation configuration utilizing ballast blocks set on extensions for slab work. A 40-foot mast was mounted to the ballasted frame for column work.
“With the cross frame ballasted the night before, a typical day on this job site begins bright and early,” said Waterman. “When the crane operators and our crews are in sync, we can fly the boom and be pouring within the first hour of the working day.”
The 39-meter boom utilizes its full 114-feet of horizontal and 96-feet depth of reach and four-section Roll & Foldâ design from the mast. This boom design was particularly important as crews proceeded with bottom-up pours on those columns close to the mast, where the ability to snake the boom around the bases of the columns from 40 feet up was the perfect solution. To accommodate every corner of the south end of the site, crews remove the ballast blocks and relocate the mast and frame with one pick to other areas of the site. Brundage-Bone plans to utilize two complete masts and booms to cover the 175-foot by 800-foot footprint.
Despite the fact that four cranes service the Intel site, the contractor and pumper both agreed that the pumps and placing booms offered the most efficient method of concrete placement. “With all of these cranes on site, none of them are flying concrete. That’s not their job, it’s our job,” said Waterman.
During the design phase of the Generation 2, Schwing ensured it would work with a variety of mounting options, the most popular of which is the tubular mast and floor frames available with a self-climbing option. Other mounting alternatives include: wall truss, lattice tower, ballasted cross frame, foundation frame and the configuration utilized at the Intel site, a combination cross frame. When on highrise work and utilizing a self-climbing form system, the tubular mast can be attached to the forming system, or a zero-elevation frame can be clamped to the working deck of the forms.
“The flexibility afforded by this technology is phenomenal,” said Waterman. “Today we’re here pouring slabs and columns. With the ability to fly and retruck this boom in a minimal amount of time, we could be out at a bridge job or residential site tomorrow. The Generation 2 will continue to be an effective tool for our contractors and provide scheduling advantages for us.”