World’s First 3D-Printed Concrete Arched Bridge Completed

After announcing the project earlier this year, Zaha Hadid Architects and the Block Research Group at ETH Zurich have completed Striatus, the world’s first 3D-printed concrete arched bridge. Located in Venice, the 16-by-12-meter (approximately 52-by-39-foot) footbridge was developed in collaboration with Incremental3D, and Holcim. The project merges traditional building techniques with computational design and robotic manufacturing, presenting an “alternative to traditional concrete construction” that has a lower embodied carbon than reinforced concrete, according to a ZHA press release announcing the project’s completion.

Striatus comprises 53 concrete blocks held together by compression, without conventional steel reinforcement, binder, or glue. Instead of printing each block in horizontal layers of concrete, the design and fabrication teams used a series of striated angles that run orthogonal to the path of the bridge’s structural forces, lending the structure its inherent strength, according to ZHA.

Each of the concrete blocks was printed using a two-component concrete ink developed by Holcim. Steel tension ties resist the horizontal thrust of the voussoir arches, and neoprene pads placed between the concrete blocks control friction and minimize stress. The bridge can be disassembled and reassembled, or recycled once the structure has outlived its use.

Striatus will be on view at the the Venice Architecture Biennale until November 2021.