In the main hall of the research and robotics Arch Tec Lab on Hönggerberg campus, several robotic arms hang from the roof, while half-finished beige-coloured curved structures reminiscent of sand sculptures are dotted around the floor. On one side of the room, mysterious parts protrude from wooden crates.
Standing in front of one of these crates is Patrick Bedarf. He works in Professor Benjamin Dillenburger’s Digital Building Technologies group and completed his doctorate at the end of September. As part of his doctoral thesis he studied how lightweight insulating construction elements – especially more complex shapes – could be manufactured to reduce materials. To do so, he used sustainable insulation material produced by the ETH spin-off FenX using recycled industrial waste. “The mineral foam we use is an innovative construction material that contributes to a more climate-friendly industry,” Bedarf explains.
The foam is mostly made from fly ash, a waste product from industrial blast furnaces. “This material has therefore already gone through the first material cycle, and can simply be recycled after use,” Bedarf explains and crumbles between his fingers the random component he has just pulled out of the wooden crate. “The material can now be reused as a novel foam.”
Less material used
The production of insulating wall elements is a sustainable process: the doctoral researcher uses 3D printing to reduce material wastage and CO2 emissions. “The formwork needed for pouring material is no longer required. Formwork is very time-consuming and can only be partially reused afterwards,” Bedarf says. Excessive wastage is a particular challenge when producing more complex geometrical shapes.