Nijmegen has longest 3D concrete printed bicycle bridge in the world

At 29 meters long, Nijmegen recently boasts the longest 3D concrete bicycle bridge in the world. The project is unique because the bicycle bridge was designed in complete freedom of form, thanks to research at Eindhoven University of Technology and the further development of 3D concrete printing technology. Characteristic of the new appearance in the Dukenburg park De Geologenstrook are the round and sloping shapes.

The bridge was printed layer by layer in the concrete printing plant of Saint Gobain Weber Beamix and realized by construction group BAM. In addition to being the longest, it is also the largest concrete bridge in the world where the architect had complete freedom. Michiel van der Kley was able to design freely and was not constrained by the material or by traditional processes, such as concrete formwork.

Since the span is not constant everywhere and thus the changing weight of the structure had to be taken into account, it was decided during the printing process to divide the bridge into printable parts. Via a parametric model - that is, based on data - the final design was generated.  

Faster and more flexible

Printed bridges can basically be built a lot faster than regular bridges, with more flexibility and more room for personalized designs. In addition, they are more sustainable because less concrete is needed. The ambition of the partners of this innovative project is to use 3D concrete printing to eventually achieve a sustainable construction method, which can be used to produce bridges and houses, among other things. 

This is also the reason that Rijkswaterstaat took the initiative for this project together with designer Van der Kley. They donated this special bridge as a lasting reminder to the municipality of Nijmegen in honor of being elected European Green Capital 2018. 

For the right knowledge and expertise, the help of TU Eindhoven and in particular Theo Salet enlisted, an expert on 3D printed buildings. Consulting and engineering firm Witteveen+Bos translated the bridge's design into printable structural components. The parametric model of the bridge was created by Summum Engineering elaborated.

Theo Salet, professor of Concrete Structures, TU Eindhoven: "Concrete printing has tremendous growth potential. We use less raw materials and can dramatically increase construction speed. In the future, we want to make concrete itself more sustainable and also start reusing it. There are still many more gains to be made in the chain. I am also proud that the knowledge developed has found its way to the industry so quickly." 

Alderman Bert Velthuis, Municipality of Nijmegen: "We as Nijmegen are very honored to receive this innovative 3D printed bridge. We are a bridge city, and this special, innovative bridge is a wonderful addition. The bridge leads to connection: in the design and construction phase it connected the different partners, and from now on the bridge connects our residents."

Bas Huysmans, CEO of Saint Gobain Weber Benelux: "This 3D production technique yields material savings of up to 50 percent because the printer only lays down concrete where it is needed for structural strength. 3D technology is maturing and thus growing into a serious option for faster, more sustainable and cheaper construction of bicycle and pedestrian bridges, among other things." 

Michiel van der Kley, designer: "I thought it was especially important to show where we are with 3D printing technology. The design was inspired by a shape that arises in nature because it has to absorb a certain force in the most efficient way, and then now translated into a digital process. With this shape, we have made 3D printing of concrete objects more interesting again. "