Architects in Zurich are using a 3D sand printer to build load-bearing structures that are at least 70 percent lighter than current methods. Matthew Stock reports.
Westminster Abbey has survived for hundreds of years.... all without modern building methods like reinforced concrete. The techniques of the Gothic 'master builders' have largely been forgotten, but architects in Zurich are looking to them for inspiration. SOUNDBITE (English) PHILIPPE BLOCK, ASSOCIATE PROFESSOR AT THE INSTITUTE OF TECHNOLOGY IN ARCHITECTURE AT ETH ZURICH, SAYING: "We are not surprised that Gothic cathedrals are standing, but nowadays we're unable as engineers to actually demonstrate why they're standing...The master builders knew how to do that, they had to do this or otherwise they could not have kept their gothic cathedrals stable for the last 500 years, right?" They're combining classical design with some very modern methods. This floor prototype was 3D printed. It's about 70 percent lighter than traditional concrete floor slabs. What's more, it's mostly made of sand. SOUNDBITE (English) PHILIPPE BLOCK, ASSOCIATE PROFESSOR AT THE INSTITUTE OF TECHNOLOGY IN ARCHITECTURE AT ETH ZURICH, SAYING: "It's just sand kept together with a simple binder. It's a really weak material if you were to take this little piece; you could break it just by bending with your hands. But if you place it where the forces want to go, which we discovered through new algorithms that we developed, then you can actually use such a weak material to use structurally - to walk on, to have a safe structure that is at least 70 percent lighter than any floor we know. " Block and his team have demonstrated the technique on a number of prototypes.... including the Armadillo Vault - a shell-like structure made from 399 limestone pieces, unreinforced and assembled without mortar. Transferring what they call 'beautiful geometry' into a real building is the next step. This year they will build the floors for the a unit on the NEST project - a research building in Zurich to test new experimental construction ideas. It's scheduled for completion in 2018.