ETH Zurich, in collaboration with ROK Architects, has introduced a new approach to material-saving and circular construction through the Cadenza concrete staircase. Installed in the NEST building in Dübendorf, Switzerland, the staircase showcases a novel fabrication method that minimizes waste and allows for future reuse, embodying the principles of sustainability and architectural innovation.
A Reusable, Waste-Reducing Design
The Cadenza staircase, designed as part of the experimental NEST building, features 16 prefabricated concrete steps arranged in a sleek spiral. These steps were all produced using a single 3D-printed mould made from carbon fiber-reinforced PET plastic, offering a significant reduction in waste compared to conventional single-use concrete formwork. The reusable mould ensures that multiple steps can be created efficiently without the need for additional fabrication processes.
The steps, which are only 20 millimeters thick, are made of ultra-high-strength, steel fiber-reinforced concrete. Weighing just 45 kilograms each, the steps are 60% lighter than traditional concrete steps, thanks to advanced material optimization techniques.
Digital Tools for Precision and Performance
Led by Benjamin Dillenburger, the head of ETH Zurich’s Digital Building Technologies group, the project leverages digital design-to-production frameworks to achieve high precision and material efficiency. “Digital tools offer significant advantages for customized concrete structures,” says Dillenburger. “This method reduces waste and enhances structural performance, all while allowing for architectural expression.”
The computational workflow developed by ETH Zurich and ROK Architects enables the staircase to be assembled off-site and installed in tight spaces without heavy machinery, making it an ideal solution for retrofits and other constrained environments.
Sustainable and Circular Construction
The Cadenza staircase is designed with circularity in mind. Its steps are held in place using dry connections, allowing them to be easily disassembled and reused in future projects. The staircase also features a post-tensioning system using memory steel, which is activated through heat to hold the steps tightly together. This innovative system saves space and simplifies installation, while also ensuring that the structure can be disassembled for reuse.
Incorporating steel reinforcement into the concrete steps, which is typically challenging with 3D printing, further adds to the staircase’s durability and long-term sustainability. The ultra-high-strength concrete used in the project is expected to have a long lifespan, contributing to sustainability by offsetting the high carbon emissions typically associated with concrete production.
Pushing the Boundaries of Construction Technology
The Cadenza staircase is part of ETH Zurich’s ongoing exploration of cutting-edge construction techniques at the NEST building. Previous projects have included the HiRes Concrete Slab ceiling with 3D-printed ventilation ducts and robotic timber construction methods.
As the construction industry continues to evolve, ETH Zurich’s Cadenza staircase exemplifies how 3D printing and digital tools can be harnessed to reduce waste, enhance sustainability, and push the boundaries of architectural design.
Source: dezeen.com
