Cement-free mineral foams for 3D printing

ETH Zurich has launched a project known as Airlements, which pioneers the use of cement-free mineral foams derived from recycled industrial waste, including fly ash from industrial blastfurnaces, to produce 3D printed building components. Spearheaded by doctoral researcher Patrick Bedarf from Professor Benjamin Dillenburger’s Digital Building Technologies group, the technology promises to reduce heating and cooling costs and to revolutionise the efficiency of construction material usage.

The Airlements prototypes, which consist of individual parts assembled into structures like wall corner pieces, embody the principles of sustainability and efficiency, says ETH Zurich. Mr Bedarf’s research, which forms part of his doctoral thesis, focused on creating these elements, especially in complex shapes, to minimise material usage. The key innovation lies in the 3D printing process, which significantly reduces material wastage and CO₂ emissions compared to traditional construction methods. This process eliminates the need for time-consuming and partially reusable formwork, a common challenge in producing complex geometrical shapes.

“Without automation, traditional construction methods that save on materials are very time-consuming and expensive,” said Mr Bedarf. This novel approach allows for rapid prototyping; each component can be printed in less than an hour and then undergoes a one-week hardening process in a controlled environment – ensuring material integrity and durability.

The practical application of Airlements includes lightweight parts that can be easily transported and assembled on-site. Initially, Mr Bedarf experimented with concrete to reinforce the parts but successfully transitioned to using solely the innovative foam. The components can be used as insulating parts for internal and external walls and have the potential for load-bearing applications.