Quick Points:

• Precast speed allows building to dry in quickly, finishing three months ahead of aggressive schedule
• Thin brick integrates with existing hand-laid brick structures
• Cost savings allows government to exercise bid alternatives

Contents:

Summary

  Precast helps massive project deliver 89 days ahead of tough schedule

Aesthetics

  Thin brick aesthetic and speed wins versus masonry

Building Details

  Huge project with big pay off

Project Teams

  Close cooperation gets the job done

Precast helps massive project deliver 89 days ahead of tough schedule

The 711^th Human Performance Wing Complex is a centerpiece for the US military’s Base Realignment and Closure (BRAC) construction program. Located in Wright-Patterson Air Force Base, Ohio, the $194.5 million project comprises two major structures and ancillary facilities covering approximately 679,000 square feet. Housed within the one- to four-story buildings are laboratories, medical facilities, offices and a wide range of highly technical equipment.

A world leader in the study and advancement of human performance, the Wing's mission is to advance the performance of military personnel in air, space and cyberspace. The Wing is the first human-centric warfare wing to consolidate research, education and consultation under a single organization.

The BRAC schedule called for base closures elsewhere in the country, placing the Wing Complex project on a difficult timeline. The project hewed to a tight 24-month construction timeline that would allow full occupancy by September 30^th, 2011.

Thanks to an architectural precast enclosure system from High Concrete Group LLC, substantial completion came almost three full months early. According to Dave Mankowski, senior project manager for general contractor Archer Western/Butt Construction Joint Venture, “In our first meeting with the government we strongly urged them NOT to consider laid up brick veneer,” he says. “We convinced them that our base bid schedule could improve using the precast brick panels by increasing off-site prefabrication of finished walls under controlled conditions versus laid up brick veneer subject to site and weather conditions. Our detailed discussions regarding the construction schedule were a major factor in the government not electing laid up brick.”

In addition, with an award cost of $194.5 million, the government was able to exercise a number of bid alternatives. “The government exercised several bid options, in part because the precast was less costly than masonry,” says project architect Mark Farmer of Cannon Design, Inc., the architect of record for the project. “But the biggest advantage of precast was how fast this building got enclosed. Speed was critical to meeting the timeline.”

The client was appreciative. “It is nearly a miracle that we were able to take possession of a facility this large and complex 89 days ahead of the original schedule,” wrote Thomas Wells, Director of the 711th Human Performance Wing, in a letter of thanks to Archer Western/Butt Construction Joint Venture.

Thin brick aesthetic and speed wins versus masonry

The goal of Base Architect was to complement adjacent buildings with the design language previously established for that part of the campus. They wanted to match the brick color of the surrounding structures and make the new enclosures look like hand-laid brick.

Thin brick is clay or shale brick veneer that is typically 5/8” thick, instead of a nominal 4” hand-laid brick thickness. The veneer is embedded into the face of precast panels during forming, providing a realistic brick image at significant labor and material savings versus hand-laid brick. According to project principal Bill Wilson of KZF/BSWC Joint Venture, the architect/engineer for the RFP, “the Wing Complex utilizes a similar visual language to other buildings located in Area B at WPAFB. The precast with thin brick veneer effectively emulates those existing structures, to the point that you are hard-pressed to tell the difference between conventional brick veneer structures and the Wing Complex buildings.”

“There was initial resistance to a thin brick precast cladding on the buildings,” says Wilson. “To address those concerns, and at the request of the Base, we included an 11^th hour alternate for hand-laid brick. To address the visual concerns with thin veneer precast, the RFP specifications required the thin brick to have the toothed appearance of hand-laid brick at building corners, with expansion joints located at the column center lines. These design details, along with the schedule and cost advantages, helped convince the Base to go with the precast thin veneer system over a conventional brick veneer.”

Farmer agrees, “The precast with thin brick achieved an excellent aesthetic result while meeting a really challenging schedule,” he says, noting that most of the brick on the skin is a dark blend with a rake joint. “The precast lent quality control and uniformity on a huge project that would have been a challenge for local masons to accomplish in hand-laid brick. There is complete consistency as you walk around the building,” he says.

A limited amount of conventional hand-laid brick veneer was used on the round enclosure for the centrifuge. Some areas of the enclosure also received an exposed architectural buff precast with a light sandblast finish.

Huge project with big pay off

Wright-Patterson’s largest single construction project since World War II, the Human Performance Wing Complex is also the largest military project in dollars that the US Army Corps of Engineers’ Louisville District has undertaken. The project consists of two major buildings with a number of ancillary facilities.

The 200,000-square-foot North Building is four stories in height, and contains a high bay area, industrial space, dry laboratory space, the NAMRL Disorientation Device, space for a Dynamic Flight Simulator (centrifuge) and hyperbaric (altitude) chambers.

At approximately 450,000 square feet, the four-story South Building contains space for the Aerospace School of Medicine with wet and dry training laboratories, administration space, secure areas, classrooms, high bay areas with training simulators, medical clinic space, training areas, and auditorium and conference areas. Additional laboratory space includes medical research lab space, radiological, acoustical, visual, vestibular, cognitive, psychopharmacological and thermal-stress lab space, and high tech research lab space. The project also includes an approximate 9,000 square foot addition to an existing vivarium, a detached 1,500 square foot Entomology Laboratory Building, and a remote medical field training site.

Early occupancy allowed training and relocation to proceed ahead of schedule. The building was substantially complete before the specs for some of the larger pieces of equipment could be determined, so the buildings were designed with placeholder spaces that could allow equipment to move in after occupancy.

Because timing was sensitive, Archer Western/Butt Construction used creative construction scheduling to ensure the project stayed on track. Wilson cites an example: “A portion of the South Building required high resistance to vibration. In order to begin construction before the steel order arrived, a cast in place concrete structure was used for that part of the building. This allowed the contractor to construct portions of the structure before the steel arrived, and facilitated early installation of the precast panels.”

Mankowski explains, “We used a 50/50 combination of steel and cast in place structure for the two main buildings. While concrete foundations and cast in place structural concrete were being constructed on site throughout the winter of 2008/2009, we closely coordinated the shop drawings of precast panels, structural steel framing and embed requirements for the precast connections,” he says.

Mankowski continues, “Partnering with the precaster, the structural engineer, and the structural fabricator we successfully allowed off-site fabrication of precast panels and structural steel to run concurrently. In essence, three major building components were being built both on-site and off-site at the same time during the winter months! As a result, sequencing of the structural steel erection and precast panel erection was able to begin concurrently in April, 2009 versus the original scheduled start of precast in July, 2009, a 90-day schedule improvement. That schedule improvement was maintained throughout the completion and turnover of the project which gave the government a near 90-day head start on moving into the entire 680,000-square-foot complex.”

Interior surfaces of the precast panels were insulated and sealed against air infiltration, and the exterior walls were finished with drywall on metal studs. The Wing Complex is registered with US Green Building Council for LEED Silver Certification.

Close cooperation gets the job done

The tight timeframe and massive scale of the project required the close cooperation of several design-build teams. KZF/BWSC Joint Venture developed the building programs, provided the conceptual design for the buildings and prepared the RFP. Because of their detailed knowledge of the program and RFP requirements, the Army Corps of Engineers kept KZF/BWSC involved throughout construction, to provide overview of construction drawings for conformance with the RFP, and to assist in answering RFIs. Burgess & Niple provided consulting services to Cannon Design, Inc. High Concrete Group worked with general contractor Archer Western/Butt Construction Joint Venture.