Theo Salet: 3D printed concrete - beyond durability?

The idea to print concrete might be disruptive for the building industry indeed, but it’s development is not unexpected by far. Concrete has been poured continuously ever since the early 20th century by means of spraying and slip forming. The technology of 3D Concrete Printing (3DCP) only differs from slip forming in the complete lack of a form work and the digitized manufacturing process. 3DCP was already introduced about 20 years ago. Ever since more and more companies and universities showed interest in digital manufacturing of concrete structures and new and exciting showcases are presented on a regular basis worldwide. Although, the technology still being at a rather low level of readiness for the industry at this early age, the level of attention can be explained by the high benefits in case of a success like an increasing degree of architectural freedom, mass customization, a better sustainability due to opportunity to optimized structures, a healthy work conditions and finally cost and time saving on the formwork in a 24/7 production environment. The idea also seems to count on sympathy from those looking from a durability point of view, since all printed objects still are unreinforced. However, this is subject to change. Research at TU/e demonstrated to print concrete in combination with both reinforcement and fibre reinforced concrete. The proof of concept has some potential and will address for a need to study the issue of durability again in close relationship to the concrete composition (no course aggregates) and the porosity of the interfaces between the filaments. Unless, the reinforcement is no longer be made out of steel and the black and white printer can be replaced by a colour printer, printing the right time of concrete at the right place : 3D printed concrete – beyond durability!