Architecture

World’s first unreinforced 3D-printed concrete bridge displayed in Venice

World’s first unreinforced 3D-...
The structure is held together with compression, needing no steel reinforcement or mortar
Striatus is held together with compression, needing no steel reinforcement or mortar
View 11 Images
The structure is held together with compression, needing no steel reinforcement or mortar
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Striatus is held together with compression, needing no steel reinforcement or mortar
The structure will be on display in Venice until November, 2021
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The structure will be on display in Venice until November, 2021
The bridge is a collaboration between ETH Zurich and Zaha Hadid Architects’ Computation and Design Group
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The bridge is a collaboration between ETH Zurich and Zaha Hadid Architects’ Computation and Design Group
The structure has been named Striatus
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The structure has been named Striatus
The bridge can be easily disassembled and moved to a different location
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The bridge can be easily disassembled and moved to a different location
The structure is part of the Venice Architecture Biennale
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The structure is part of the Venice Architecture Biennale
“Striatus stands on the shoulders of giants," says one of its designers
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“Striatus stands on the shoulders of giants," says one of its designers
The bridge "revives ancestral techniques of the past"
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The bridge "revives ancestral techniques of the past"
The blocks utilize a novel type of concrete ink produced by a company called Holcim
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The blocks utilize a novel type of concrete ink produced by a company called Holcim
The structure is on display until the end of the year
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The structure is on display until the end of the year
3D printing the concrete blocks
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3D printing the concrete blocks
View gallery - 11 images

A first-of-its-kind 3D-printed concrete bridge has been unveiled in Venice, Italy. The bridge is a demonstration of a new 3D printing method resulting in a structure requiring no mortar or steel reinforcement.

The bridge was developed as part of a collaboration between ETH Zurich and Zaha Hadid Architects’ Computation and Design Group. The unreinforced structure was created by 3D-printing concrete blocks using a novel type of concrete ink produced by a company called Holcim.

3D printing the concrete blocks
3D printing the concrete blocks

“This precise method of 3D concrete printing allows us to combine the principles of traditional vaulted construction with digital concrete fabrication to use material only where it is structurally necessary without producing waste,” explains Philippe Block, a researcher from ETH Zurich.

The bridge "revives ancestral techniques of the past"
The bridge "revives ancestral techniques of the past"

Shajay Bhooshan, from Zaha Hadid Architects, says the project is a fusion of ancient architectural techniques and modern computational design. The entire structure, dubbed Striatus, is held together through compression, with no reinforcements.

“Striatus stands on the shoulders of giants: it revives ancestral techniques of the past, taking the structural logic of the 1600s into the future with digital computation, engineering and robotic manufacturing technologies,” says Bhooshan.

The structure will be on display in Venice until November, 2021
The structure will be on display in Venice until November, 2021

The structure can easily be dismantled and reassembled in a different location but is currently sitting at the Giardini della Marinaressa as part of the Venice Architecture Biennale. It will be there until November 2021.

The structure comes hot on the heels of another 3D-printed bridge recently installed over a canal in Amsterdam. That 3D-printed steel bridge was initially built in a factory in 2018 before being transported by boat and installed by crane into position this month.

Sources: ETH Zurich, Striatus Bridge

View gallery - 11 images
6 comments
6 comments
Don Duncan
Thanks Rich. I predict this one-of-a-kind will be the first of many. I could the tech used for houses. I like the idea of print in pieces and assemble on site. Now, for the invention of a cheap, strong, waterproof concrete.
paul314
As medieval designers discovered, the range of structural shapes that can be build under compression only is ilmited. (And even more limited in earthquake zones) This is why modern builders put reinforcement even in a simple concrete floor slab. But there are also concrete types with chopped-fiber reinforcement that can sustain at least some tension. And should be adaptable to 3D printing.
kwalispecial
I wonder if there is any more risk of weak spots due to air bubbles when 3d printing concrete, compared to poured - or other 3d printed materials too, for that matter. All those extruded beads of liquid are bound to have an occasional void, aren't they?
Graham3196
The problem of tension loads in stone and concrete can be solved in many situations by post-stressing the structure so it all stays in compression. To be "with it"
youd have to use carbon fibre cables but steel would be quite effective. It probably needs a bit of physical experiment to develop reliable standards for earthquake and long life durability but plenty of beam bridges are built this way so its only a progression from current practice. Is the concrete mix made in such a way that it doesn't slump or do we still need some formwork? Perhaps Very quick setting concrete mixed as its printed?
Worzel
The design is aesthetically pleasing, but reminds me of the ''Fiddler on the roof,'' song, with stairs going everywhere and nowhere! 3D printing is amazing in that it allows shapes to be produced that would be almost impossible by any other means.
My concerns are, how it would stand up to water ingress into the porous concrete, followed by freezing temperatures, and would it just crack and crumble? In addition, water soaked material would encourage plant life to take up residence, and that is also likely to destroy the structure, as the roots expand. Maybe it will only be suitable for warm dry climates.
I have some ''temporary'' steps formed with stacked, hollow concrete blocks, that have started to disintegrate after about five years of weathering, due to exactly those factors.
Lamar Havard
I saw a guy on YT who came up with 'aircrete' by foaming dish detergent into a meringue consistency and mixing it with concrete and water. He put a 2 ft. x 9 ft. x 6 in. slab of it, which had chicken wire embedded in it for support, on two cinder blocks and stacked TWENTY 80 lb. bags of concrete in the middle of it, stacked 5 wide, without breaking. The best part is that he and his wife can pick up the slab and walk around with it.