A Concrete Staircase named Cadenza

Cadenza, the helical concrete stair of the STEP2 Unit, has been installed at NEST in Dübendorf, Switzerland. This innovative architectural feature is a product of collaborative research led by the Chair of Digital Building Technologies at ETH Zurich. NCCR DFAB researcher Andrei Jipa played a pivotal role in the development of this cutting-edge engineering and fabrication technology. His current research focuses on 3D-printed formwork for functional concrete components, as seen in Cadenza.

The preassembled Cadenza stair in the Empa Bauhalle. Photo: Han Seul Ju

Cadenza stands out for its efficient use of high-performance materials. The steps, measuring less than 20 mm thick and weighing only 45 kg, are a result of structural optimization. Reinforcement is strategically concentrated in three memory®-steel post-tensioning bars within the load-bearing stringer, achieving a balance of strength and material efficiency. A key element of Cadenza's design is the use of reusable 3D-printed formworks, allowing for the creation of complex shapes that would be difficult to achieve with traditional methods. This approach not only reduces material consumption but also aligns with sustainable construction practices.

Modularity and sustainability are central to Cadenza's design. The staircase and landing are assembled with dry connections, enabling easy disassembly and reassembly. This approach promotes the principles of circular economy architecture, emphasizing resource conservation and adaptability. Cadenza serves as a practical example of how computer-assisted design and 3D printing can transform architectural innovation.

Looking ahead, the construction of STEP2 at NEST promises further advancements in architectural design and construction, with an expected completion date in spring 2024. Cadenza is a testament to the ongoing evolution of NEST as a hub for innovative and sustainable building solutions.

Finde more information about the project on the DBT Website.

The project brought together a team of experts, including Digital Building Technologies ETH Zürich, ROK Architects, SW Umwelttechnik, the BASF subsidiary Forward AM, New Digital Craft, WaltGalmarini AG, and the Empa spin-off re-fer.