Two world’s first 3D printed reinforced concrete bridges
Yesterday (20 September), the world’s first reinforced concrete bicycle bridge was opened in Gemert (in Dutch), the Netherlands. On the same day, a scale model of a girder for the world’s first 3D printed car bridge was tested. Early next year, the actual bridge should be ready near Blauwestad (in Dutch), also in the Netherlands.
3D printing bridges isn’t new per se. Earlier this year, we reported on the first 3D printed pedestrian bridge in the world, located in Madrid, and in the Netherlands there is a 3D printed metal bridge. The difference, however, between these bridges and the new ones is the material (metal versus reinforced concrete) and the size (pedestrian versus bicycle and car bridge).
3D printing concrete
3D printing concrete has several advantages over normal casting methods. For one, less concrete is needed, as the concrete is only deposed as needed. Since producing concrete releases a lot of CO2, 3D printing concrete is less harmful to the environment. Another advantage is creative freedom. 3D printed concrete does not need a mould, and the concrete can be printed in any desired shape.
The concrete is thicker than usual, so that it retains its form as it is printed. The 3D printer adds a steel cable during the printing process, pre-stressing the bridge.
The 8-metre (26-feet) long bicycle bridge was placed yesterday in Gemert, in the province of Noord-Brabant, by construction company BAM Infra. On 17 October, the bridge will be opened festively.
The province of Groningen is working together with the company FDN to create the world’s first 3D printed car bridge, also made from reinforced concrete. The bridge will be 20 metres (65 feet) in length and 8 metres (26 feet) in breadth, with 2 car lanes. The surface, railing and foundation will all be printed, as first in the world.
Yesterday, a scale model of a girder, also printed by the TU Eindhoven, was tested to see how much weight it was able to carry, which over 6 tonnes (6.6 US ton). Later this year, a complete test bridge will be printed and placed near Blauwestad. If that test is successful, the actual bridge will be printed and placed early next year, claiming the name of biggest 3D printed bridge in the world.