STEP2: digitally manufactured concrete staircase

STEP2 is the name of the next unit in NEST, the research and innovation building of Empa and Eawag. The unit is still in the planning phase, but parts of the staircase have already been prototyped and recently passed the final prototype tests. The pioneering STEP2 project demonstrates the potential of polymer 3D-printed formworks for free-form geometry. It will feature a unique staircase with fibre-reinforced concrete steps only 2 cm thick. The complex topology is designed to minimise material, expressing an innovative structural and tectonic concept based on discrete prefabricated concrete steps assembled with shape memory alloy prestressing bars. Ultra-high-performance concrete enables the striking slender design with steps weighing only 54 kg, circa 60% less than a conventional alternative.

Visit the EMPA website for more details on the project.

Stair design: Digital Building Technologies – ETH Zurich, ROK Architects
Fabrication system: Digital Building Technologies – ETH Zurich, SW Umwelttechnik
Formwork development and 3D printing: Digital Building Technologies – ETH Zurich, BASF Forward AM, New Digital Craft
Structural design: WaltGalmarini
Precast concrete: SW Umwelttechnik
Post-tensioning system: re-fer
Project management: ROK Architects

Rendering: Digital Building Technologies, ETH Zurich