Planners working on the design for a physicians’ center in Stamford, Connecticut, decided to combine the office and parking needs, creating an integrated plan that took full advantage of a precast concrete structural framing system. The project features five levels of parking with three levels of medical offices above them.
“The significant advantage that precast concrete provided was that it offered a consistent and uniform structure and appearance throughout the medical and parking levels,” says Robert Koenig, senior project manager at Suffolk Construction, the construction manager on the project.
The new Stamford Integrated Care Pavilion / Medical Office Building is located adjacent to the Stamford Hospital and will provide ambulatory and specialty-care services that create a coordinated health service, officials say. The facility provides 247,046 square feet of offices and parking on a 120 x 300 square-foot footprint. “The hospital campus space was very tight. Rather than create a low-rise medical building with separate parking alongside, we decided to build both facilities in the same system.”
Blakeslee Prestress fabricated the 912 precast concrete components needed, which included double tees, girders, columns, shear walls, spandrels, stairs, slabs, and wall panels. The work was completed on a design-assist basis, with Blakeslee’s engineers providing input during the design phase to plan the most efficient sizes and panelization options.
“We looked at cast-in-place concrete and steel, as well as hybrid systems,” Koenig says. “None of them provided the benefits of the precast concrete system. It offered the most effective system and could be erected quickly to keep us on schedule.”
The design features embedded thin brick in the panels at the office levels along with curtain wall at the entrance to create a distinctive welcoming design. Parking levels feature tall spandrels that reflect the design of the ribbon windows used on the office levels above. “The look is differentiated between the functions, but it has a similar language and is complementary,” Koenig explains.
A topping was used on the office levels to provide fire separation from the parking levels, and they were outfitted with interior corridor walls and an elevator core.
Erection is moving quickly on the congested site, with the contractor coordinating with local traffic officials and police to smooth access for the delivery of the precast concrete components. “There are a high number of deliveries coming through, but everything has moved quickly and efficiently.” The components are picked from the back of the truck and set, with no staging area required.
The design-assist format aided the fast erection, which began in January and is expected to be completed in April. Blakeslee provided all aspects of the precast concrete design, manufacturing, and field operations, creating a single point of contact to keep the process efficient.
The structure features a long-span prestressed concrete double-tee framing system, offering 60-foot clear spans with minimal floor construction depth. “Long-span construction along with inherent durability and fire resistance are key, common, advantages for both parking and office uses,” notes Chris Zarba, Director of Sales and Project Development at Blakeslee.
Blakeslee worked with the owner’s design team to develop a unique lateral-bracing system that addressed the functional and operational needs for the two office occupancy uses. The lateral design utilized precast lite walls at the parking levels which integrated with the sloping, ramped, floors needed for vehicular circulation. The lite walls would have been a hindrance in the office space, so Blakeslee suggested a precast moment-frame system for these upper levels to provide large open floor plates with minimal columns and no shear walls.
On the office levels, precast insulated thin brick-clad, loadbearing spandrel panels provided multiple cost efficiencies. The components combined all of the elements of a conventional ‘built-up’ exterior system, with separate structure, insulation and exterior finish components. “That resulted in a huge reduction and compression overall of the project schedule,” says Zarba.
The precast concrete structural solution achieves the objectives of lowest cost and fast schedule, which can be attributed to making use of its inherent ‘off site construction’ techniques, he notes. “When coupled with the advantages of integrated mixed-use occupancies not readily attainable by other construction methods, the precast system provides an excellent choice for many projects.”
Koenig agrees that the design offers benefits that other projects can use. “There aren’t a lot of these types of projects done these days, in which the parking and office space are combined,” he says. “But it’s a system that works very well, and I expect it will catch on.”