A Parking Garage that Blends In and Stands Out
A Parking Garage that Blends In and Stands OutFirst multi-level parking garage constructed in Benton County, Arkansas
STURTEVANT, WI (October 10, 2006) – Located in the upper northwest corner of Arkansas, the Northwest Arkansas Community College (NWACC) can claim fame to building the first multi-level parking facility in Benton County.
The Bentonville-based college led the way in developing the county’s first tiered parking structure when predictions indicated that 30 prime acres of asphalt parking space would be needed within ten years to accommodate an estimated 10,000 students. With land precious, NWACC realized its most viable solution was to build skyward.
Parking structures go up nationwide every day. So, what makes this one special? More than just a ‘first’ within an area of explosive business growth, the NWACC ramp is also noteworthy in the construction world for its highly appealing design and the fact that the actual garage was erected in less than 90 days.
Aesthetics are Important
Under a design directive to blend with the other college buildings, the 821-space parking structure is not your typical gray concrete garage. MAHG Architecture Inc. of Fort Smith, Arkansas integrated a stunning “Plantation Red” brick veneer and impressive archways to provide a pleasing appearance. Clearly, the eye-catching design makes the structure stand out when compared to the majority of parking facilities.
“It was a really good looking garage with close attention paid to its aesthetics,” says Job Superintendent Bryan Hayden of Nabholz Construction Company. Nabholz’s Ozark Division, based in Rogers, Arkansas, was selected to construct the 277,084 sq. ft. parking facility, which is comparable in size to five football fields, each stacked atop the other.
“We had a very short time frame to complete the entire structure before the college’s fall session started,” notes Hayden. “But it was completed on time with a grand opening in mid-August, where the facility was noted as setting a higher standard for parking facilities.”
Swift and Efficient
“It was an extremely fast-paced job,” says Jim Lay, Executive Director of Construction Management at NWACC. “We completed the actual garage in just 89 days, from the first column being erected to the last piece put in place.”
The overall project was completed four months faster than normal due to foundation work being done on-site, while the pre-cast panels were being simultaneously built elsewhere. Although this meant accomplishing two major tasks at the same time, it resulted in three months of pre-planning efforts, followed by an exorbitant amount of detailed coordination throughout the actual building process.
“Due to extremely tight space constraints on-site, the project was orchestrated so ‘nothing hit the ground’,” according to Lay. “We just didn’t have the space to store any pre-cast panels during construction.”
Therefore, all pre-cast panels were shipped in numbered sequence according to a carefully planned build and ship schedule. When trucks arrived, the panels were removed and immediately erected in a connect-a-piece approach similar to working with Legos®. As a credit to the production fabricator, the pre-cast pieces fit as planned for crews to position about 35 panels daily.
The Pre-Cast Approach
Coreslab Structures handled all the pre-cast work, shipping the respective panels from their Oklahoma and Arkansas facilities. The exterior featured pre-cast wall panels with architectural brick snaps already incorporated into the concrete. Meanwhile, the interior incorporated the less visible gray pre-cast structural shear walls and double “T” floor panels that were supported on pre-cast reinforced concrete structural columns and beams.
Although the double “T” floors required a five-inch thick top concrete layer, they were sent at a reduced two-inch thickness to provide a lighter shipping weight from Conway, Arkansas. This allowed two panels at a time to be shipped instead of one, realizing a $200,000 savings in transportation costs.
However, once on the site, the double “T” floors needed a three-inch topping slab for each 55,000 sq. ft. parking level. Cantera Concrete Company of Tulsa, Oklahoma was called to handle the concrete placement and finishing.
“We had to contend with hot 100-degree summer temperatures while working with a stiff 5,000-psi concrete mix,” says Jerry Turner, Project Manager at Cantera. “Plus, it was pumped in rather large 13,000 sq. ft. sections.”
“Finishing crews had to really work quickly, as the hot mix would set extremely fast,” says Ryan Langston, Nabholz Project Coordinator. “We would start pumping at about 4:00 am and that afternoon, we would already be walking on it and saw cutting control joints.”
“The pre-cast construction process is definitely the way to go with a fast paced project,” adds Langston.
Pumps Keep Up the Pace
Cantera kept up the swift pace by relying on the efficiency of high output Putzmeister truck-mounted boom pumps, which were supplied by Williams Concrete Pumping located near Tulsa, Oklahoma. Williams had the equipment, experience and the dedication to be on-site pumping concrete every other day once the project was 25 percent underway.
During an intense three-week period, Williams’ Putzmeister BSF 36-Meter boom pump was predominantly used until reaching the upper levels. At that point, Williams brought in the largest unit in its fleet – the Putzmeister BSF 52Z-Meter with a 170 ft. vertical and 158 ft. horizontal reach. Both units were capable of high outputs over 200 cubic yards an hour.
“Cantera likes speed when pumping, and so do I,” says Richard Williams, co-owner of the pumping company started in 1981. “So when a pour allows it, we run our pumps wide open to get their jobs done as efficiently as possible. However, when we need to add extra delivery line, it naturally slows down the process a bit.”
“Each bay was 60 foot wide; and when reaching the furthest point of concrete placement in the center of the top level, up to 90 foot of extra delivery line was needed,” claims Lay. “The pumps did a great job and covered a lot of territory in a short amount of time.”
“Even when it was necessary to add delivery system, the pumps still averaged about 75 cubic yards an hour,” says Turner. “That’s really quite an impressive figure for using so much extra hose.”
Although Williams’ home base is located about 90 minutes from the job site, their pumping services were still requested by Cantera. “We’ve only had positive experiences with Williams,” says Turner. “They show up on time, the equipment reliably performs, and the pour gets done as planned.”
“The project was on such a high-speed schedule that we’d often leave our boom pump in a secure area on-site and just drive back and forth,” says Barbara Williams, co-owner of the pumping company. “It was very important that we were always ready to pump concrete when they were.”
In total, 1,000 cubic yards of concrete was needed for the 57,990 sq. ft. slab-on-grade; and 2,200 yards for the three-inch topping slabs, totaling 219,094 sq. ft. The concrete mix was supplied by Mid-Continent Concrete of Bentonville, Arkansas.
“Projections indicate the need for a second 1,000-space parking garage over the next decade,” says Lay, “and I would surely recommend this same construction approach again.”
Completion of the entire $23 million college expansion is anticipated in spring 2007. The overall project includes the parking facility, a new student center, central energy plant and a renovation to the existing student center to convert it into classroom and administrative offices.