Digitally fabricated concrete formwork pushes the limits of what can be cost-effectively constructed in concrete

As architectural teams continue to push the limit of building design with ever more complex geometries, engineering and construction firms must develop clever solutions to execute these daring schemes on time and within budget. 

During the course of several recent projects, engineers with Simpson Gumpertz & Heger (SGH) and fabricator CW Keller have created an integrated approach to model, design, and off-site fabricate formwork for complex concrete geometries. The process combines SGH’s expertise with concrete materials, construction, and analysis of intricate assemblies, with CW Keller’s advanced modeling and computer numerically controlled (CNC) fabrication capabilities, to create geometrically complex, prefabricated formwork systems.

“The combination of advanced CNC machining and emerging technologies in construction materials is pushing the bounds of what can be cost-effectively constructed in concrete,” says Matthew Johnson, Principal with SGH. Johnson says the two disciplines—structural engineering and formwork fabrication—work hand in hand since the fabrication model can serve as the basis of analysis models. As a result, “teams can assess many options early and rapidly,” he says. 

On the team’s most recent project, the new Gulf Stream Tank at the Patricia and Phillip Frost Museum of Science in Miami (pictured above), the prefab process saved roughly nine weeks of the project schedule compared with conventional site-constructed formwork. The elevated tank structure is 125-foot-diameter, conical, cast-in-place concrete construction. It will hold more than 500,000 gallons of seawater, and will feature an acrylic oculus to offer museum visitors views into the tank from below. 

Also on the Building Team: Grimshaw (architect), Baker Concrete Construction (concrete subcontractor), Peri (shoring contractor), and Skanska (GC).

Photo: CW Keller

Photo: CW Keller

Rendering: Grimshaw