ETH zurich uses foam 3D printing to produce recyclable formwork in concrete casting

exploring the potential of foam 3D printing in construction

constructing geometrically intricate forms for concrete elements that are optimized for resource efficiency is often wasteful and labor-intensive. to address this issue, in their latest research project, the DBT unit of ETH zurich university explores how foam 3D printing (F3DP) can be used to produce intricate shapes for functional stay-in-place or temporary and recyclable formwork in concrete casting. the resulting mineral composite elements are capable of saving up to 70% concrete, while they are also lighter, and they feature improved insulation properties. the printable mineral foams based on recycled waste are developed at ETH zurich in collaboration with fenX AG.

all images courtesy of DBT

generating an impact in the construction industry

the DBT unit at ETH zurich (find more here) has developed a prototype that demonstrates their new approach, through the geometry of 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, with the resulting geometry requiring 24 formwork elements in 12 unique shapes. these elements are all fabricated with a robotic foam 3D printing setup. then, they are placed manually inside a conventional timber perimeter formwork, before casting ultra-high-performance fiber-reinforced concrete (UHPFRC). after curing, the timber formwork is removed from the prototype and the structural building element is completed.

this novel fabrication technique is expected to heavily impact the responsible and sustainable consumption of resources and energy in the construction industry. the newly introduced approach enables the manufacturing of geometrically complex foam elements that were previously unfeasible and wasteful to produce with conventional methods. the foam shapes produced with F3DP can be used as stay-in-place applications or removed and recycled for printing the next formwork.