A pedestrian bridge has been 3D-printed in Lyon by a team that included Swiss cement-maker Holcim, British designer Zaha Hadid Architects, ETH Zürich and Austrian printing specialist Incremental3D.
The precursor project to the Phoenix bridge was announced in 2021 and carried out at Holcim’s French Innovation Hub.
The bridge gains its structural strength from compression, which means that it needs no mortar or reinforcement, and the material required to make can be cut by about half. The concrete blocks it is made from contain recycled materials and they can be disassembled and recycled, making the building process circular.
Edelio Bermejo, Holcim’s head of research and development, said: “Phoenix is the result of a fruitful collaboration with our partners to meet a common goal: demonstrating that essential infrastructure can be designed and built in a way that is circular and low-carbon.”
Philippe Block, the co-director of ETH Zurich’s Block Research Group, said: “Concrete is an artificial stone, and like stone, it does not want to be a straight beam, it wants to be a masonry arch.
“Following these historical principles allows us to keep materials separated for easy recycling and to dry-assemble the structure for easy deconstruction and reuse. 3D concrete printing allows us to use material only and exactly where needed."
Holcim will carry out further tests and look for way to scale up the printing process.