Belgian-Dutch consortium builds new aircraft viaduct at Schiphol Airport

Construx b.v. is one of Europe's leading manufacturers of formwork systems and precast moulds for concrete elements, both for use on the site or construction site and in the production or prefabrication hall. The systems are used daily in the realization of infrastructure projects, artworks and industrial complexes. Together with its Dutch branch, in partnership with Heijmans Infra b.v., it managed to win the contract for the new Schiphol VDRQ aircraft viaduct.

The family business, founded in 2003, is already a fast grower. The Construx group already comprises five companies in Belgium, including the main offices in Hulste, one in the Dutch town of Veenendaal and one in Bucharest, from where the Eastern European market is handled. Innovation, co-creation, flexibility and customer orientation are the pillars of its success. And she was also able to play these to the full in the Schiphol project.

Limited space and minimal inconvenience

The new aircraft viaduct over the A4 will be adjacent to the already existing viaduct and will rest on 65-meter-long pillar beams. Under each of these beams are nine piers, three of which are situated in the intermediate verges of the A4. To minimize inconvenience to through traffic, formwork supplier Construx b.v. developed, in collaboration with Heijmans Infra b.v., a unique, pre-assembled and largely interchangeable pillar formwork. Only one nightly road closure was sufficient for the assembly team to place the complete formwork (including intermediate beam formwork) of the pillar wall.

Herry Van Houten, director of the Dutch subsidiary of Construx-Dijkhor b.v.: "The space in the intermediate verges of the A4 is extremely limited. Therefore, the pillar formwork was assembled as much as possible on the pre-construction site next to the viaduct. Afterwards, the nine pillar formwork, including beam formwork and reinforcement, were placed on site in one move. This has already saved the contractor a considerable amount of time, allowing the structural work to be delivered in October 2021."

Short lead time and assembly time

Van Houten: "With a view to the shortest possible lead time, the formwork was center-pinned. This way, the contractor does not have to finish the pillar wall after the formwork is removed. Moreover, we designed the pillar formwork so that the various parts were interchangeable and could be used interchangeably without any problems. The same goes for the 34 platforms along the formwork. This reduces the chance of anything going wrong during assembly." Van Houten already looks back with satisfaction on the project, which offers a fine example of co-creation and out-of-the-box thinking. Combined with a flat organizational structure, which is also present at Heijmans Infra b.v., with quick decisions as a result, all this led to a remarkably short construction process.

Some facts and figures

Some figures to indicate the scope of the project: the new viaduct is 250 meters long and 60 meters wide. Each pillar wall is 65 meters long and 5.20 meters high. Each pillar wall contains over 265 m3 of concrete, accounting for more than 20,000 m3 of concrete in the entire project. The entire structure has a bearing capacity of 32 MIO kg and 900 foundation piles were installed for this purpose. And something that can count toward sustainability: working with a concrete plant on site saved no less than 52,000 kilometers of transport movements.