A newly installed 3-D printer at the Netherlands’ Eindhoven University of Technology (TU Eindhoven) that enables production of concrete objects of up to 11 meters long, 5 meters wide and 4 meters high is opening new possibilities in the design and manufacture of building components.

The printer, one of the first of its kind and dimensions in the Netherlands, and with one of the largest build volumes of any 3-D printer in existence, resembles an overhead hoisting crane in a production hall with a jointed, swivel printer head for concrete taking the place of a hoisting cable. Attached to this by means of a hose is a concrete mixing and pump unit.

Print head of the 3-D concrete printer and some first samples of printed building elements. Image credit: Rien Meulman. In traditional concrete pouring, the formwork determines the ultimate shape of the concrete, limiting design options. However, printing concrete allows designers to create fine concrete structures, potentially enabling builders to fabricate details as small as a pea.

The printer also prints diverse types, qualities and colors of concrete together in a single product. For instance, an entire wall can be printed with various layers and functionalities embedded at the production phase: for example, fiber-reinforced concrete to make it strong, an active insulation layer to retain heat, dirt-repelling concrete on the outside to keep it clean and a layer that enhances acoustics.

Printing concrete also allows smart components to be printed at the desired location. For example, wireless sensors to measure the temperature, or lighting that is triggered when someone enters the room.

Before that is achievable, researchers Theo Salet, TU Eindhoven professor of concrete structures, and PhD student Rob Wolfs have several challenges to overcome. For example, when printing a new layer of concrete, the underlying layer has to have enough bearing capacity so that it does not collapse while remaining moist enough to adhere to the new layer.

The researchers are investigating new kinds of concrete that will comply with both requirements. They expect the first products to be commercially available within five years.