Because the site for the new Birck Nanotechnology Center at Purdue University is near an airport serving the university, structural work had to be sequenced in an unusual way.

Normally, a crane would never enter the footprint of the building and would put up all structural steel from outside that footprint during one sequence of construction. But because of the Birch building's proximity to the airport, crane height was limited, which meant the crane had to be situated within the footprint. The building's center section was erected first and the rest of the building erected in nearly two dozen different sequences as work proceeded from the center out.

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"We couldn't do the slab on grade at the outset because a crane would have to sit there," said project manager Chris Rayner of Indianapolis-based Pepper Construction Co. of Indiana LLC, the general contractor. "And we couldn't do the underground plumbing for the same reason. The waffle-slab concrete was a very intense concrete undertaking and would have normally been done simultaneously with structural steel erection."

Begun in June and slated for completion in July 2005, the 187,000-sq.-ft. Birck Nanotechnology Center is budgeted at a cost of $58.3 million. The center's structural support is a combination of steel and concrete, with steel frame used for the front of the structure and vibration-controlling, cast-in-place concrete at the rear.

The exterior will be clad in precast concrete and a metal siding system, said Gene Hatke, senior architect with the office of the university architect at Purdue. An attention-getting architectural feature at the center of the structure will be clad in copper panels.

Part of Discovery Park

The Birck Center is part of Discovery Park, which was established about four years ago on the southwest edge of the Purdue University academic campus as a focal point for research-oriented facilities. The park could eventually include a dozen or more such buildings devoted to research by university faculty and students, as well as private sector researchers working in cooperation with the university.

Three separate buildings are currently under construction at Discovery Park - the Birck Center; the Bindley Bioscience Center, which will be connected to Birck; and the Burton Morgan Center for Entrepreneurship, which will house meeting rooms and demonstration facilities and serve as the park's hub.

Hatke estimated that more than $100 million will be spent on the three structures and the park's utilities infrastructure. Funding is almost exclusively through gift donations, much of it from alumni. The Birck Center is by far the largest structure at Discovery Park, and roughly half the money expended at the park thus far have gone into that facility, Hatke said.

Life in Miniature

The building of the Birck Center reflects the growing importance of nanoscience, or the study of microscopically small particles. "Nano is Greek for a billion, so a nanometer is a billionth of a meter," Hatke said. "If you take a pen and draw a line, that line is about a million nanometers wide. Nanotechnology is the effort to apply nanoscience.

"The hallmark of this facility is that it will not be exclusively engineering or science or computer, but all those disciplines will use the building. We will have biologists, chemists, material sciences, electrical engineers all working together. This gives Purdue the opportunity to compete for research grants that require that cross-expertise."

The site of the center is directly north of the airport and some railroad tracks, and that worried planners that plane and train vibrations might have made the site unsuitable for such a center.

"The first thing you want to do with a nanotechnology center is get someone to analyze the site, primarily from the standpoint of ambient noise or vibration," Hatke said.
"Some of these guys are working with individual atoms, and you have to have a pretty stable environment to do that."

Fortunately, site analysis proved that, at about a half-mile distance, the airport and tracks were far enough away that they did not pose a problem. The distance also meant that the center's 75-ft.-high exhaust stacks would not impede air traffic to and from the airport.

Clean Rooms Installed

The nature of the microscopic analysis to be done at the Birck Center necessitated the inclusion of clean rooms in the facility. Clean rooms control airborne particles and are designated by class, such as class 1000, class 100 and class 10.

The lower the number, the cleaner the air, with the numbers referring to the acceptable number of airborne particles in the room. "In a class 10 clean room, they have a ceiling that's probably 100 percent filtered air inlet," Hatke said.

"The whole ceiling is an array of filters, through which air is arriving in the room, moving at about 70 ft. a minute and then being removed from the room through the floor. It goes through various filters before returning through the ceiling into the room."

The Birck Center will feature about 23,000 sq. ft. of clean room space, which will be laid out in a bay-and-chase configuration, Hatke said. Researchers will work in a dozen enclosed bays situated next to chases, rooms through which air will circulate before being filtered.

Concrete is the most conspicuous material used in constructing the clean rooms. The support below the clean rooms is provided by a grid of concrete columns at 16 by 18 ft.
The concrete structure spanning that grid is a 30-in. deep concrete waffle slab. "You need the short spans and deep structure for rigidity," Hatke said. "Within the clean rooms themselves, it's a panelized system made specially for clean rooms."

The Birck Center will stand 60 ft. tall and include just two stories, with mechanical "penthouses" above the second floor.

Rayner said the rainy summer of 2003 was an "obstacle" for the construction team. He said the rains forced the team to dewater the site and pick up lost midweek construction days on Saturdays.

"We've made up for lost time in the six months we've been out there," he added.