Optimization of Concrete Mixture for 3D Printing

3D printing is one of the latest state-of-the-art technologies for construction applications. The use of a 3D printer is more economical and time efficient, eliminates the formwork, requires less labor, has less safety risks and minimizes construction errors. Further, the sustainability is increased because less construction waste is generated. With 3D printing a new market can be entered, as the binder can be sold as an ink instead of a cement. In this case, the regulation will be different and might go in the direction of performance-based criteria.

Only a small body of literature is available concerning printing with alternative binders, such as alkali activated materials, that originates from slag. The commonly used alkali activated material for 3D printing are ground granulated blast furnace slag, metakaolin or fly ash, but not yet an Fe-rich slag. In this research, an Fe-rich inorganic polymer (IP) will be 3D printed. An IP is produced by alkali activation of an Fe-rich slag, which is a metallurgical residue and is only used nowadays for low value applications. IPs are proven to be interesting for building applications and are able to achieve mechanical performances similar or even superior compared to traditional cement. Furthermore, IPs have a lower carbon emission compared to the cement.