Engineer Scales Up 3D-Printed Concrete Structures

Last month, Megan Kreiger spent more than a week at Camp Pendleton in Southern California, 3D printing a 32-ft-long reinforced concrete footbridge. When she first arrived, it rained so much there were mud slides. “It’s hard to print in torrential downpours,” she says. “It was crazy.”

The skies eventually cleared, and the bridge, her latest research project, printed. After all work on the custom gap crossing is done, Kreiger aims to 3D print a modern-day version of a Bailey bridge. “It would be phenomenal if we could make a bridge that could support a tank,” she says.

The footbridge pilot project came on the heels of a successful Kreiger-led research project—the first full-scale 3D-printed reinforced concrete building in the U.S. engineered for permitting.