In a project called FoamWorks, researchers at ETH Zürich explored how foam 3D printing can be used to produce unique shapes for functional stay-in-place or temporary and recyclable formwork in concrete casting.

Making geometrically complex formwork for concrete elements that are optimised for resource-efficiency are often wasteful and labour intensive. To make these types of formwork more sustainable, the researchers at ETH Zürich explored the possibility of 3D printing the foam.

The foam they used is a printable mineral foam made of recycled waste and developed in-house in collaboration with FenX AG. As proof-of-concept they created a 2 x 1.3 m ribbed slab with point supports in every corner. The rib layout follows the isostatic lines derived from the principal stress pattern. The resulting geometry requires 24 formwork elements in 12 unique shapes.

The foam elements are made with a robotic foam 3D printing setup. They are deposited in a timber perimeter formwork after which ultra-high-performance fiber-reinforced concrete (UHPFRC) is cast. Once this is cured, the formwork is removed, The result is a. Structural building element that saves up to 70% concrete, is lighter, and has improved insulation properties.

This new method allows for a less material and energy consumption to make geometrically complex elements. Other projects by ETH Zürich can be found here.

Photos: ETH Zürich