Quadrupling Port Columbus International Airport's Parking Settember 1999

The Port Columbus International Airport is recognized as one of the fastest-growing airports in the United States. Serving more than 6.5 million passengers a year, the Columbus, Ohio, airport records more than 400 international and domestic flights a day – or nearly 18,000 passengers.

To keep up with the airport's pace, in 1998 the Columbus Airport Authority launched a construction program to more than quadruple the current covered parking facilities. "Located just seven miles outside downtown Columbus, it's a great business-traveler airport," said Jack Jones. He would know. Not only does he travel for P.J. Dick Inc., a large Midwest general contractor, but he's also project superintendent for the airport's $94 million construction project.

"The 6-story parking expansion is tremendous," said Jones. "This huge garage will hold more than 4,000 cars, and it will include covered parking facilities for the rental car lots." Both are very important to business travelers in the Midwest.

The 1.6 million-square-foot (487,680 m2) parking structure is part of a construction plan that will include new roadways, corkscrew ramps, connecting buildings, elevators, escalators and more. P.J. Dick began pouring concrete on the site in October and projects the garage will be fully operational by January 2000.

According to Jones, one of the toughest aspects of the job has been working in an extremely tight job site. The new parking garage is sandwiched between an existing garage on one side and surrounding live roadways that feed the airport terminals on the others. Another problem has been the extremely harsh concrete mix required for the structure. The company has relied on a Putzmeister 52Z-Meter boom pump to help meet both of these challenges.

Jones said the company has built many parking structures in the past, but this is the largest. The basic plan has been to pour the columns, then slab on grade or decks and repeat, building up. So the company divided each 300,000-square-foot (91,440 m2) level into four quadrants. Each approximate 250- x 250-foot (76 x 76 m) section required three pours.

P.J. Dick found the best way to reach the deck pours was with a 52Z-Meter Putzmeister boom pump. It's the only five-section Z boom in the 170-foot (52 m) height range, giving the company three or four boom sections of reach over the deck.

The company's original plan was to use a mini-placer for the out-of-reach areas, but it scrapped the idea after they put the pump to work. "Considering all the work required to build the gangways and fit pipe for a mini-placer, we probably saved 20 percent on our total concrete placement labor cost by going to the 52Z," said Jones. "The pump has helped us stick to a very tight schedule. We just set it up and let it go."

"We've been pouring nearly an acre of concrete a week, and it has gone unbelievably smooth," said Jon Abbey, P.J. Dick's vice president and general manager. "Even with the harsh mix we've been using, the 52Z hasn't had any blockages. We weren't as lucky with another pump."

Jones said the company used an extremely harsh mix with an accelerating corrosion inhibitor to gain strength early – 3,000 psi (20 N/m2) in two days – and stop salt from penetrating the rebar in the concrete. Using superplasticizer, the concrete had a maximum of 8-inch (203 mm) slump. Without the superplasticizer, he said it was a 1 1/2-inch (38 mm) slump. The mix was 7,000 psi (48.3 N/m2) for the columns on the bottom four levels and 5,000 psi (34 N/m2) for the decks.

The garage also contains 2.4 million linear feet (731,520 m) of post-tension cable and 3,300 tons (2,994 metric tons) of rebar.

P.J. Dick has averaged two to three pours a week, anywhere from 350 to 800 cubic yards (320 to 731 m3) each. By the time the company is done, the garage will contain approximately 65,000 cubic yards (59,436 m3) of concrete.

"The 52Z has saved a lot of time and money with its reach on this job site," added Jones. "A five-section boom puts concrete where a four-section can't. And the Z-boom is more maneuverable than a roll-and-fold configuration, letting our operators put concrete in place on this tight job site."

At its peak, the company employed nearly 280 workers on the project. The company completed the last major pour with the pump in July.