Project Overview
Given one year from notice to proceed to occupancy, architects used contrasting colors of architectural precast concrete wall panels to clad the building and provide a distinctive, random-looking exterior.
It took precast to a different level by creating different forms and using undulations to really showcase the entry and make it different. The building was designed around prototypical planning modules consisting of a one-story computer room, two-story electrical-equipment bar and a series of offices. The precast concrete panels provide durability and the hardened shell required by these high-security facilities.
Precast Solution
Two types of panels were used to achieve the distinctive contrasting pattern. Eight × 52 ft (2.4 × 16 m) tall panels featured formliner finishes, while 10 × 35 ft (3 × 11 m) panels had a solid black integrally colored finish. Panels were 7 or 8.5 in. (180 or 220 mm) thick.
The panels were cast at two plants, with each plant casting one type of panel. The gray form finish and black light-medium sandblast panels required close attention to quality control to ensure uniformity. Metakaolin was used to reduce efflorescence and improve appearance and performance. Weekly skin coordination meetings were held with the precaster, design team, and structural engineer.
Reinforcing bar dowels protruding about 10 in. (250 mm) from the bottom of the panels were used to slide the panels into cast-in-place concrete embeds consisting of a corrugated duct mounted to a thin plate. The precaster used a PVC sleeve on the reinforcing bar to connect to rock even after the duct was grouted. |