Striatus, an innovative 3D printed masonry bridge recently opened to the public as part of the Venice Architecture Biennale. The bridge was built by The Block Research Group (BRG) at ETH Zurich, The Computation and Design Group at Zaha Hadid Architects, incremental 3D and Holcim
Introduction
The project began with the selection of a basic 2D form, which was then translated into a 3D model using advanced software. Employing thrust network analyses, the force diagrams for each design iteration were meticulously created. The ideal curvature and 2-meter extrusion were identified, followed by the design of 3-meter high balustrades or railings. Employing a Sterotomy mesh, the bridge was divided into 53 wedge-shaped blocks known as voussoirs.
Structural load calculations were conducted using advanced discrete element analysis to assess stress, deformation, and displacement in the bridge. To mitigate the risk of structural failure caused by excess load, the design was adjusted accordingly.
The bridge’s innovative construction process utilized a two-component concrete ink with corresponding printing head and pumping arrangement. Each of the 53 blocks was printed in non-uniform and non-parallel layers using a 6-axis robotic arm, enabling forms that require no reinforcement or post-tensioning. The resulting structure, acting as a series of leaning voussoir arches, showcased the brilliance of ancient Roman arches and Nubian vaults adapted for modern technology.
Design
In contrast to traditional concrete construction, where solid, heavy blocks are used, Striatus achieved strength through geometry rather than mass. With each section of the bridge being hollow, material usage was reduced by 30%, and steel usage was minimized to just 10%, effectively cutting transportation and labor costs.
Transported from Germany to Venice, the 3D printed forms were carefully assembled on-site, ensuring the bridge’s sleek and intriguing design complemented the surrounding landscape. The bridge’s eco-friendliness is highlighted by its minimal material usage, ease of disassembly, and potential for recycling, making it a prime example of the 3 Rs – reduce, reuse, and recycle.
Conclusion
While Striatus stands as a testament to human intellect, machine computing, and the latest technology, a few limitations exist. The bridge is not wheelchair accessible due to space constraints, and some modules faced breakage during shipping and installation, leading to significant delays. Moreover, the clash between machine precision and human inaccuracy necessitated adjustments on-site.
Nonetheless, the Striatus 3D printed concrete bridge represents a groundbreaking achievement, pushing the boundaries of what is possible with modern technology and intelligent design. Its awe-inspiring aesthetics and eco-conscious approach make it a symbol of progress and innovation in the world of construction.
