On a sunny day, Peabody Plaza looks more like a painting than a structure. The 290,000-ft² office building’s façade uses an artistic combination of patterned precast concrete panels, brick, and glass, to create an ever-changing reflection of the surrounding city.
The new building and adjoining park replaced a 250-space parking lot on a bluff overlooking Cumberland River, giving the community greater access to the views and nature surrounding the site.
Initially, designers planned to use a glass curtainwall system for the project, but instead shifted to a window wall supported by a precast concrete framework. “We chose precast concrete as the spandrel panel primarily to allow the design team the opportunity to mold the panels to the desired shape and for the flexibility in color and finish,” explains Chuck Gannaway, principal at Hastings.
Precast concrete also brought “affordability, durability, and interesting finish colors and textures,” notes Chris Cruze, project manager for Gate Precast Company.
A Good Ribbing
The façade design is a nod to the adjacent historic trolley barns. The concept required precast concrete spandrels and columns covered with a 6-in. trapezoidal projection that runs the length of each piece and aligns to the adjacent spandrels, column covers, or both. The shapes extend to all-glass corners at both the southeast and northwest corners to denote major entry locations. The main floor of the building on the southeast corner has structural columns wrapped in polished precast concrete.
The depth of the projections was accentuated by lightly acid-etching the rib component, leaving its finish lighter and homogenous, while deeply polishing the larger adjacent back body faces. The polishing reveals a Tennessee black granite aggregate to create a darker, more reflective contrasting face.
The tight jobsite resulted in limited staging areas, causing alternating loads to be stored in different locations. “Our shipping departments excelled in overcoming these challenges, which allowed for a continuous flow of product to the project site, allowing the installer to complete the installation in an expeditious manner,” Cruze says. To add further efficiencies, the precast concrete producer produced the architectural precast concrete panels at two of its prefabrication facilities, which involved very detailed communication and timing between both facilities’ shipping departments and the erector.
Once on-site, the various project teams worked collaboratively, sharing cranes and coordinating their work to ensure multiple subcontractors’ sequences could be performed in sync. “The installation of the precast concrete was completed by wrapping the building finishing one floor at a time, due to the challenge of using on-site tower cranes during a second shift,” Cruze says.
The finished project features the ten-story building, along with a 37,500-ft² pocket park and promenade that establishes a pedestrian connection between the metro city’s downtown and a multiuse trail.
“We love the shape of the precast and the resultant shadows that it casts in different light and at different times of the day,” Gannaway says. “The ability to see and touch these finishes up close at the column covers displays the refinement of the product.”