ETH Zurich has unveiled details of their latest investigation into advanced building materials in construction. The project, titled FoamWork, explores how foam 3D printing can assist in creating concrete formworks. The initiative saw ETH Zurich’s Digital Building Technologies team work in collaboration with FenX AG to develop the printable mineral foams, based on recycled waste.

“FoamWork explores how foam 3D printing (F3DP) can be used to produce unique shapes for functional stay-in-place or temporary and recyclable formwork in concrete casting,” the team explained. “The resulting mineral composite elements can save up to 70% concrete, are lighter, and feature improved insulation properties.”

As part of the design process, a prototype ribbed slab measuring 2m x 1.3m (6.5ft x 4.2ft) was developed by the team, with an isostatic pattern shaped by principal stress lines. The resulting geometry required 24 foam elements in 12 different shapes to act as a formwork.

The foam elements were created using a 3D printed robotic arm, before being manually placed in a conventional timber perimeter formwork. The piece was cast in an ultra-high-performance fiber-reinforced concrete, with the timber formwork removed after the mixture had cured. The foam shapes can be used as stay-in-place applications or removed and recycled for printing in later formworks.

News of the technology comes two months after ETH Zurich unveiled a robotically-assembled sculpture inspired by the Hanging Gardens of Babylon. The university also recently unveiled HiLo, a research building on the institute’s Duebendorf campus featuring a doubly curved concrete roof, lightweight funicular floors, and self-learning building technology.

In the 3D printing space, the institute was also recently involved in the creation of the world’s first 3D printed concrete footbridge built without any reinforcement, which was showcased at the 2021 Venice Architecture Biennale.