with concrete responsible for 8% of our global carbon footprint, it is more important than ever to use the material more efficiently.

although optimization algorithms can significantly reduce the amount of concrete used on complex buildings, the construction industry remains limited by the available fabrication technologies. to tackle this problem, digital building technologies, ETH zürich has proposed an automated solution that combines the fabrication speed of concrete 3D printing with the geometric precision of reusable 3D printed formwork.

The two square meters slab prototype is assembled using post-tensioning tendons image by axel crettenand, all images and video courtesy of digital building technologies, ETH zürich.The project, titled ‘fast complexity’, has been demonstrated with a highly optimized post-tensioned structural slab prototype.

‘to make this possible, we developed an innovative process that allows us to dynamically control the setting rate of the 3D printed concrete,’ explains digital building technologies. ‘this digital control over material properties means that we can extrude a fluid concrete that emulates the complex surface of the formwork perfectly, as well as a fast-setting concrete that does not need any additional formwork for the upper structure.