holcim 3D prints phoenix, a reinforcement-free concrete bridge

Phoenix: the first-of-its-kind circular 3D-printed concrete bridge

Holcim introduces Phoenix, a 3D-printed concrete masonry bridge created with 10 tons of recycled materials. Developed in collaboration with Block Research Group at ETH Zurich, Zaha Hadid Architects Computation and Design Group, and incremental3D, this sustainable infrastructure utilizes Holcim’s proprietary concrete ink with recycled materials inside, marking a significant step presented at their Innovation Hub in Europe.

Phoenix’s inception arose partially from the recycling of aggregates from the original blocks of Striatus, the first 3D concrete printed bridge without reinforcement launched by the partners during the 2021 Venice Biennale of Architecture. Edelio Bermejo, Head of Global R&D at Holcim, emphasizes the project’s alignment with sustainability goals, stating that Phoenix ‘demonstrates that essential infrastructure can be designed and built in a way that is circular and low-carbon today.’

image by Vincent Delesvaux

marrying innovation with circular design

Phoenix merges innovation with circular design, highlighting the potential for a more eco-conscious infrastructure landscape. Circular construction, integrating computational design and 3D printing, facilitates a possible reduction of up to 50% in material usage without compromising performance. Phoenix, designed with circular principles, relies on compression alone, devoid of reinforcement, utilizing blocks that can be easily disassembled and recycled. Philippe Block, Co-Director of Block Research Group at ETH Zurich, highlighted the historical masonry arch principles employed in the design: ‘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. The result is a sustainable and truly circular approach to concrete construction.’

‘Phoenix is a significant milestone in technology readiness. It showcases the maturation of integrated design to construction technologies,’ comments Shajay Bhooshan, Head of Computation and Design Group at Zaha Hadid Architects, on the project’s technological advancement.‘Now, after two years and in its second iteration, Phoenix adds a largely reduced carbon footprint and permanence according to building codes along with many other further improvements,’ describes Johannes Megens, Co-Founder of incremental3D. Using its ECOCycle® circular technology, Holcim and its partners are exploring now potential routes to scale up Phoenix for broader implementation in sustainable infrastructure solutions.

image by Block Research Group