World’s largest and longest 3D-printed concrete bicycle bridge: some observations 4 years after its construction

The BAM construction group constructed the largest and most extensive concrete bridge using 3D printing technology. According to available information, the world's longest 3D-printed concrete bicycle bridge measures 29m in length and was inaugurated on September 8th, 2019. The architect, Michiel van der Kley, had full creative authority over the design, a result of a request from the Nijmegen municipality. Traditional processes like concrete formwork were not limiting factors, enabling him to work creatively on the project.

Rijkswaterstaat, the Dutch Directorate-General for Public Works and Water Management, initiated the project in 2019 following Nijmegen's selection as the European Green Capital in 2018. Bureau Witteveen+Bos oversaw the construction of the parametric model, and Summum Engineering served as the technical engineer.

Bas Huysmans, CEO of Saint Gobain Weber Benelux, explained that the 3D printing technique used reduces material usage by up to 50% because the printer only places concrete where structural strength is required. He also noted that 3D technology is evolving and becoming a viable option for faster, more cost-effective, and environmentally friendly construction, particularly for structures like bridges.

Witteveen+Bos utilized 3D printing technology to fabricate the bridge's structural components, realizing Michiel van der Kley's concept. Subsequently, Summum Engineering developed a parametric model based on this data to finalize the bridge's design. The model factored in various structural constraints and was divided according to printing specifications set by TU Eindhoven. Additionally, an optimized internal geometry was generated for the bridge.

Professor Theo Salet, an expert in Concrete Structures at TU Eindhoven, expressed enthusiasm for the substantial growth potential of concrete printing. He highlighted the reduced consumption of raw materials and the potential for significantly increased construction speed. Salet also underscored the aim to make concrete production more sustainable and explore avenues for reusing it.

Michiel van der Kley emphasized the importance of showcasing the progress made with 3D printing technology. He designed the bridge drawing inspiration from natural shapes that efficiently absorb specific forces, which were then translated into the digital production process. Several details about the design of the bridge can be found here.