IN: Inspiration

Function and Flow

Researchers at Switzerland’s ETH Zürich have developed a concrete ceiling slab using 3D printed formwork.


The most commonly used resource in construction, concrete, is also among the most versatile. From minute decorative details to the substructures of skyscrapers, one cannot imagine a world without concrete!

Swiss university of science and technology ETH Zürich is no stranger to the diverse uses of concrete. Last year, researchers managed to construct a concrete ceiling whose width tapered to as little as 3cm. Fast-forward several months and they’ve built a concrete ceiling whose rippling form uses minimal concrete partially just 20mm thin – and is exquisite!

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The final and largest segment of the Smart Slab - weigthing almost 2.5 tonnes - being installed on site. © Digital Building Technologies (dbt), ETH Zürich/ Andrei Jipa


The “Smart Slab” – as it’s called – forms part of a larger project called DFAB House. What distinguishes DFAB House is that it is built using novel digital fabrication methods, including an autonomous on-site robot, collaborative robotic prefabrication and additive manufacturing. DFAB House is a three-storey structure and the ceiling alone must support the two-storey load directly above.

For the Smart Slab, researchers used digital design strategies to minimise the amount of concrete needed to produce the ceiling by inputting relevant parameters like room shape and dimension adjacent structural elements. With this knowledge, the formwork is built using 3D-printing technology and includes 11 segments, which are then sprayed with glass-fibre-reinforced concrete. These concrete segments are then connected to form the Smart Slab.

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The Smart Slab segments being placed piece by piece on the 12cm wide mesh mould wall. © Digital Building Technologies (dbt), ETH Zürich / Tom Mundy


While the Smart Slab is much lighter and thinner than comparable concrete ceilings, it still weighs 15 tonnes, and relies for support on its ribs through which steel cables will be threaded both vertically and horizontally. A full two weeks is also needed for the concrete to harden into the breath-taking pattern.

Through their daring and innovation, ETH Zürich seem set to revolutionise concrete by developing new and fascinating applications. For the full story, visit:

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The hierarchical grid of structural ribs of the Smart Slab. © Digital Building Technologies (dbt), ETH Zürich / Andrei Jipa

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