A new language for concrete

The first of its kind, Striatus establishes a new language for concrete that is digital, environmentally advanced and circular by design.
It uses concrete at its best by placing it precisely where needed with minimal material use - doing more with less with no compromise on performance and aesthetics. Here, concrete is unreinforced, holding through compression, structurally informed, fabrication-aware, precisely placed and ecologically responsible.

Photos of completed bridge in Giardini Marinaressa, Venice © Studio NAARO

Strength through geometry

Achieving strength through geometry, the Striatus bridge stands solely through compression without reinforcement. Using advanced technologies, from computational design and engineering to robotic manufacturing, Striatus revives traditional master builders’ techniques to create a high-tech masonry structure.

Key structural principles of Striatus © BRG, ZHA,IN3D

3D Concrete Printed masonry

Striatus follows a masonry logic on two levels. Globally, the bridge behaves as a series of leaning unreinforced voussoirarches, with discretisations orthogonal to the dominant force flow in compression, following the same structural principles as the arched Roman bridges in stone. Locally, on the level of the voussoir, the 3D-printed concrete layers behave as traditional brick masonry, similar to the inclined rows of bricks in Nubian or Mexican vaulting.

Robustness load bearing capacity of 3DCP masonry © BRG, ZHA,IN3D

Robotic 3D printing of concrete

Unlike typical extrusion 3D printing in simple horizontal layers, Striatus uses a two-component (2K) concrete ink with corresponding printing head and pumping arrangement to precisely print non-uniform and non-parallel layers. This new generation of 3D concrete printing in combination with the arched masonry design allows the resulting components to be used structurally without any reinforcement or post-tensioning. For Striatus, Holcim developed a specific, custom-made proprietary 3D-printing ink from its Tector® 3D Build range of mortar inks.

Non-parallel, force-aligned print path generation and concrete printing © BRG,ZHA,IN3D

Computational design to construction integration

Integrating design, engineering, fabrication and construction, Striatusredefines conventional interdisciplinary relations. The precise manufacturing of the blocks was enabled by well-defined data exchange between the various domain-specific software toolchains involved in the process. This co-development approach was facilitated through the use of COMPAS, an open-source computational framework for collaboration and research in the Architecture, Engineering & Construction (AEC) industry, which enabled the fluent interaction among the key players of the project, working together in five different countries, under a very tight schedule and budget, at a time in which travelling was not possible.

Integrating design, engineering, fabrication and construction aspects © BRG, ZHA,IN3D

3D concrete printing

Robotic 3D printing of concrete © BRG, ZHA,IN3D

Assembly

On-site assembly of pre-fabricated, concrete printed blocks © BRG, ZHA,IN3D
Video footage of completed bridge in Giardini Marinaressa, Venice © Studio NAARO