September 2017 saw the opening of the world’s first 3D-printed reinforced concrete bicycle bridge. Construction of the bridge began in June and was spearheaded by the Eindhoven University of Technology (TU Eindhoven)based in Eindhoven in the Netherlands, in collaboration with construction and infrastructure group BAM.
The concrete bicycle bridge measures eight metres long and three-and-a-half meters wide. TU Eindhoven’s bridge is made of printed, pre-stressed and reinforced concrete, and will be used by cyclists to cross the Peelsche Loop, a canalised river in the town of Gemert in the Netherlands.
To build the bridge, the 3D printer released a toothpaste-like fluid concrete onto the printing plate, forming the elements of the bridge, layer by layer. The specially formulated concrete allows the material to maintain its form once printed. This means traditional formwork is not required to keep it in place while it sets.
“We have a world first here,” says Marinus Schimmel, director of BAM. “With 3D printing, you have more flexibility regarding the shape of the product. In addition, 3D printing a bridge is also incredibly efficient: you need less concrete, but there is also no need for shuttering where the concrete is normally poured in. You just use exactly what you need,” he adds.
In the months leading up to the construction of the bridge, the research team made an initial scale model (1:2) and tested its safety by subjecting it to a 2000 kg load. Once the safety had been demonstrated, the team began printing the concrete elements that were later glued together to form the bridge.
While the bridge is not the first to be built using a 3D printer, it is the first 3D-printed bicycle bridge of its kind. Last year, a 3D-printed pedestrian bridge was built in Madrid, Spain. The research team at the Eindhoven University of Technology has already begun tests for a bridge that will be able to carry a weight of more than six tonnes.