In collaboration with project developer Tervia’s, Witteveen+Bos is working on the development of a cement-substitute mixture. This mixture is being developed from geopolymers for use in a full-scale 3D printer. With this development, it is our ambition to realise the first application of 3D printing at a construction level. The part of the construction not printed will be developed, as much as is possible, circularly.

Pros and cons of 3D printing

3D printing offers several important advantages. Objects can be printed quickly, for example, and the use of materials is kept to a minimum. As well as this, it fits in with the wider digitalisation of the construction industry and offers a great deal of freedom in terms of form. The disadvantage of the technique, however, is that printed concrete is responsible for a large CO₂ impact because of the cement it contains. This impact can be two to three times more than that caused by traditional concrete. By feeding a 3D printer with geopolymer concrete, we can commit fully to a pioneering construction technique without sacrificing on sustainability. This creates a win-win situation, as printing requires much less material and, by using geopolymer concrete, it also becomes more sustainable.   

Witteveen+Bos guides development process of geopolymer concrete

In order to obtain the most appropriate composition, it is essential that consideration be given to several parameters throughout the development process:

• the mixture must be able to be printed, meaning it has to be stackable;
• it needs to be capable of being pumped to the printer’s nozzle;
• the mixture must also satisfy the relevant construction regulations.

Witteveen+Bos is guiding the development of the geopolymer concrete. During the design and subsequent printing processes we will also provide the necessary technical assistance. We are aiming to deliver this world-first in spring of 2022 at a yet-to-be-determined project location in Belgium.