Zaha Hadid Architects and ETH Zurich have built a 3D-printed concrete footbridge named “Striatus” in Venice that is freestanding and assembled without mortar, according to Dezeen. The 52-foot long bridge was constructed from 53 hollow blocks each printed from 500 layers of printed concrete.
The structure is an unreinforced arched bridge that uses compression and gravity to hold its form, according to the article. The studios arranged the 3D-printed wedge-shaped elements, known as voussoirs, to form arches and vaults. The bridge has a double-curved deck with swooping stepped entry points placed at either end of the bridge, leading up the structure from its footings.
Contrasting typical 3D-printing methods, which use horizontally layed extrusion techniques, the bridge used a single six-axis robotic arm to print non-uniform and non-parallel layers across its 53 blocks. The blocks took 84 hours each to print while its construction took 35 days. By creating hollow blocks, the designers aimed to reduce typical material use and consumption.
According to Dezeen, the studio looked to historic masonry vaulting to inform its design. No glue or adhesives were used during the construction, and instead neoprene pads were placed between each of the printed blocks during assembly to control the levels of friction and stress.
