[dropcap size=big]T[/dropcap]he 3D Printed Reinforced Beam is part of the ongoing research of Digital Building Technologies into 3D printed, structural building components. Two-sided cantilevering beams, up to 4.5 meters long, are fabricated out of sandstone. Components are 3D printed on a large-scale binder-jetting machine. All seven interlocking segments are dimensioned to fit the printer’s maximum volume. Binder-jetting allows for the multiple functionalities such as integration of custom enclosures, for post-tensioning cables and complex joints for assembly.

Because sandstone printed elements can only take compression forces, the structural system is designed so that, after pre-stressing, the printed elements become compression-only. The structural evaluation regards the beam as one structural element, with no degrees of freedom between its components. Through several design iterations joints that interlock the components have been developed, making the beam one structural element.

Designing for 3D printed building components means creating a computational design system that generates printable complex geometries  with high resolution of detailing. Such a system profits from the geometric freedom that binder-jetting offers and integrates mass customization into the design and fabrication.


Research for this project was carried out at the Chair of Digital Building Technologies, ETH Zurich.

Beam II

  • Sand-printed elements (silicate and binder)
  • Number of components: 7
  • Dimensions (Lxlxh) : 4.5×0.2×0.35 m
  • Total weight: 165 kg
  • Printing resolution: 0.25 mm
  • Printing time: 48 hours

Beam I

  • Sand-printed elements (silicate and binder)
  • Number of components: 7
  • Dimensions (Lxlxh) : 4.5×0.3×0.4 m
  • Total weight: 260 kg
  • Printing resolution: 0.3 mm


  • Ana Anton
  • Thodoris Kyttas
  • Ahmed Elshafei