Parking for 2,000
Parking for 2,000Putzmeister pumps handle complicated nine-story parking structure
STURTEVANT, Wis. (May 1, 2005) – Two years ago construction began on the new south parking deck on the University of Arkansas campus. Upon completion in summer 2005, the nine-story cast-in-place concrete structure will be the largest in Arkansas, housing well over 2,000 cars.
During construction, a number of innovative and state-of-the-art construction elements were employed to accomplish the $25 million project. Precision blasting twice a day was used to excavate nearly 50,000 tons of rock from a hill and allow for the lower levels of the deck. The deep excavation was designed to maintain a lower profile while providing adequate parking and respecting the important aesthetic heritage of the university.
As space is precious and the university growing so rapidly, the only place to build is up – thus the nine-story garage. The structure will use post-tension construction; and unlike most parking decks, it will have a light-colored ceiling up to 11-ft heights along with a center-shaft to provide additional light and ventilation.
Structural advances include construction of an open cavity system surrounding the deck, but discretely bridged-over to provide an even-grade aesthetic. The construction includes three "fast service" elevators, and a two-story transit facility, complete with some prime ground-level space for retail and commercial development.
Responsible for the building project is general contractor Baldwin and Shell Construction of Little Rock, AR and concrete place and finish contractor Cantera Concrete, Inc. LLC of Tulsa, OK. Williams Concrete Pumping near Tulsa, OK is pumping the concrete that is being supplied by Central Ready-Mix branches in Springdale and Farmington, AR.
According to Brent Dostal vice president of Cantera, “This was definitely not your typically flat parking garage. It’s really an impressive and enormous structure consisting of all slopes. We dealt with winding curves, unique beams and huge columns.”
In total, the job covered almost 900,000-sq. ft. The first slab on grade pour occurred in January 2004. Initially, the concrete supplier wasn’t aware of the high volume outputs the Putzmeister equipment and crew were capable of handling. However, they geared up for all subsequent pours, often relying on two batch plants to supply the mix.
Notably, the concrete mix had a high cement content and low 4-inch slump, yet the boom pumps with their field proven S-valve gulped it down without difficulty. Even with the uncommon concrete mix, the pumps averaged 125 yards an hour output – although 160 yards an hour was not uncommon.
Barbara Williams, co-owner of Williams Concrete Pumping said, “Overall, it was a fairly complicated job to pump. Besides having a very restricted area for setup, we also had to work around a crane in the middle of the structure.”
The parking facility, built into a rocky hill, only allowed access to place the concrete from two sides. The site also demanded that the concrete pumps nestle into some rather awkward and tight areas. To avoid traffic congestion and disruption to the campus, all pumping occurred after midnight and needed completion by morning.
The project was divided in two sections – initially building half of the nine-story structure against the hill. For the large deck pours, the Putzmeister 52Z-Meter was needed for its longer reach in pumping the large 500 to 900 cubic yard areas – the size being dictated by engineering design. For the smaller ramps and elevator shafts, the 32- and 36-Meter concrete boom pumps provided ample reach.
Rick Williams, co-owner of Williams Concrete Pumping said, “When pumping progressed to the upper levels of the nine-story structure, our 52Z-Meter was extended almost straight in the air with its hose leading to our mini-placer for added reach.”
Ken Williams of Williams Concrete Pumping noted, “For the first half of the nine-story garage, we did three pours per floor until we reached the top floor. The crane was then moved back, and we then pumped about 720 yards of concrete on each floor to finish up the first section. The process repeated itself for the other half of the 92-ft tall structure.”
Brent said, “Over the course of a year, we relied on Williams Concrete Pumping and their Putzmeister pumps to place 23,000 cubic yards of concrete in 48 different pours. What’s impressive is that there was never even the slightest mechanical problem, which is a real compliment to the performance of their equipment and its reliable upkeep.”
Brent added, “Although we could have selected a more local company, as Williams was over 125 miles away from the job site, we still depended on their pumping services and used them even without a backup pump on site. That’s putting a lot of faith in a pumping company; because if there had been an equipment malfunction that would have stopped a pour, we could have lost the job’s profit in just one night.”
General contractor: Baldwin and Shell Construction – Little Rock, AR
Concrete contractor: Cantera Concrete Company, Inc. LLC – Tulsa, OK
Pumping contractor: Williams Concrete Pumping – Inola, OK
Ready-mix supplier: Central Ready-Mix – Springdale and Farmington, AR