Fast Complexity: Efficient and customizable concrete 3D printing

Additive manufacturing is starting to play a very important role in the construction industry. Concrete 3D printing keeps gaining more and more popularity among architects and construction firms for two main reasons – it is cheaper and faster than the conventional processes. Plus, as concrete contributes 8% to the global carbon footprint, it is vital to use it as efficiently as possible, and the existing optimization algorithms allow to cut the amount of material needed in half! But architects have been facing a problem: fabrication technologies are quite limited when it comes to building quickly and at low costs. The conventional formworks (a mold into which concrete is poured) allow to build only predefined geometries with limited customization. That’s where project Fast Complexity comes into play – ETH Zurich introduced an automated solution that combines the fabrication speed with the geometric precision of concrete 3D printing.

Image credit: Digital Building Technologies

Concrete 3D printing

Technically, concrete 3D printing is not drastically different from FDM 3D printing, only the size of the printer is much bigger and instead of a filament, concrete is used. Both concrete 3D printers and FDM printers are controlled via g-code, a machine language that directs the print head of the 3D printer until the desired 3D model is produced. The similarity between plastic FDM printers and concrete printers can be summed up in two words: material extrusion.

Project Fast Complexity

To demonstrate their new method Digital Building Technologies, ETH Zurich used a highly optimized structural slab prototype. A slab is a structural element made of concrete, it’s used to create horizontal surfaces such as floors, ceilings, etc. ETH Zurich’s unique process allows to dynamically control the setting rate of the 3D printed concrete. In other words, builders can “extrude a fluid concrete that perfectly emulates the complex surface of the formwork, and a fast setting concrete that does not need any additional formwork for the upper structure”.