Curve Appeal

High Concrete precast system is key in ‘gravity defying’ 1200 Intrepid

Denver, Pa.-based High Concrete Group played a key role in creating a “gravity defying” 92,000-sq.-ft., four-story office building in the heart of Philadelphia’s Navy Yard Corporate Center. World-class architectural firm Bjarke Ingels Group (BIG), based in Copenhagen and New York, designed the $34 million 1200 Intrepid to mimic the curves of the adjacent Central Green park. Challenged with this unique design opportunity, High Concrete Group’s engineering team developed a precast component system necessary to execute the curved façade.

“High Concrete saw our design as a wonderful opportunity to really show off their skills, talents and products,” says BIG partner Kai-Uwe Bergmann, AIA, RIBA. “It has been a sincere joy to work with a group of precasters who are as engaged as they have been, willing to roll up their sleeves to work on solutions rather than seeing obstacles and I am sure that they are as proud of their efforts as much as we are.”

Selected by Turner Construction, High Concrete produced 421 architectural precast panels totaling 29,000 square feet of vertical surface for all four elevations of the building under a $2.7 million contract. Over a few short months the panels were delivered and installed from November 2015 through January 2016.

The company also designed a structural steel system that was embedded into the precast panels to transfer the load through them to the foundation. The interlocking panels appear to be 11 inches thick; however, the backs of the panels were partially hollowed out, reducing their thickness to 4.5 inches at the face to minimize the weight. “This project presented an extremely high degree of difficulty for constructing precast in an innovative way,” says Glenn Ebersole, High Concrete’s market development manager. To create the slope and curve on the east side, he adds, each precast panel is positioned at a different angle and rotation, requiring a high level of precision during the installation.

“On the 1200 Intrepid Project, the High Concrete Group was able to take the architect’s 3D marketing model, adapt it for the 3D design of the building’s panels and connections [with Tekla Structures BIM software], translate it into the fabrication of the individual precast panels, and use it for the complex layout of each connection for the construction of a very complicated compound curve façade,” explains Roger Gentry of Turner Construction. “Once on site, the High Concrete team met every schedule milestone and helped make the project a success. With the help of people at High Concrete, Turner was able to deliver to the client a façade that met every expectation of appearance and quality put to the project. The complex geometry of the feature façade has become a show stopper to all that visit the Navy Yard.”

To create the slope and curve of 1200 Intrepid’s east façade, each precast panel is positioned at a different angle and rotation. PHOTOS: High Concrete Group
The precast panels carry perimeter loads in tandem with structural steel members.