Architects use 3D printing to create a beautiful concrete bridge
Researchers around the world are using 3D printing to create a wide range of products. Generally, we believe that 3D printing is used for small plastic objects, such as parts for cars and other small components for device prototypes. However, engineers are studying and using 3D printing to build much larger structures in the construction industry.
Researchers from ETH Zürich recently worked with engineers from the Block Research Group and Zaha Hadid Architects, as well as other partners to create an interesting 3D printed concrete bridge in Venice. One of the most interesting aspects of the 3D printed concrete bridge is that it does not have any reinforcements inside. The team claims that millions of new buildings around the world are made of reinforced concrete despite the fact that the construction generates large amounts of CO2 emissions.
The steel used for reinforcement and the cement are known to be among the biggest polluters of CO2 in the world. The 3D printing bridge project shows how to reduce CO2 emissions from cement and steel production in a real project. The project is a 12 by 16 meter arched walkway placed in a park in Venice that was built entirely without reinforcement.
The bridge is called Striatus and was created using an additive process involving concrete blocks that form an arch similar to a traditional masonry bridge. The compression-only structure allows forces to move to the soles, which are tied together to the ground. The researchers note that the dry-assembled construction is stable due to its geometry alone.
3D printed concrete is a whole new type developed by researchers with help from a company called Incremental3D. Rather than being applied horizontally as is the case with concrete construction, the material was applied at specific angles, so it is orthogonal to the flow of compressive forces. This pattern holds the printed layers in the pressed blocks together without the need for reinforcement or post-tensioning. In addition, the structure does not require mortar allowing the disassembly of the blocks so that the bridge can be reassembled in another place. If the bridge is no longer needed, the material can be separated and recycled.