Margaretha Zelle Aqueduct

A major project to upgrade the N31 and create new approach roads

Use of high-grade concrete results in an extremely satisfied client

The Province of Friesland, the Directorate-General for Public Works and Water Management and the Municipality of Leeuwarden are taking steps to improve access to Leeuwarden. These include a major project known as ‘De Haak om Leeuwarden’ (‘The Hook around Leeuwarden’), which involves upgrading the N31 and constructing new approach roads. The part of the project for which we were responsible was the ‘Margaretha Zelle Aqueduct’ on the western approach road (now known as Johannes Brandsmaweg). The roadway constructed beneath the aqueduct has two lanes in each direction and a cycle path and crosses the Van Harinxma Canal.

  • 2 lanes in each direction
  • 15,000 m2 surface area
Working and casting concrete under water are areas in which we are successfully specialised for many years now. However, this project still represented a major challenge, because of the large area of concrete – 15,000 m2 – and the high quality requirements involved. The client wanted the concrete to comply with the rigorous CUR 100 standard. This is concrete that is virtually perfect and has a completely smooth surface. As a result, no algae can stick to it, it retains its attractive appearance for a long period of time and also requires little maintenance.

Careful mixing

To achieve concrete of such high quality, each formwork component could only be used once. Mixing and casting also had to be carried out extremely carefully – a laborious and costly process, but one that delivered an attractive and durable result. The finished structure was so impressive that the client also arranged for other contractors to come and take a look at our concrete.

Acceptable vibrations

During the work the canal remained open to shipping traffic at all times. The nearby industrial estate, railway line and railway bridge also remained in use. Particular attention had to be paid to the railway bridge, as even minimal subsidence could have had major consequences for rail traffic. Vibrations were also monitored in accordance with strict standards. The end result was a process that ran extremely smoothly.

More information?

Ronald de Geus

Managing Director Ballast Nedam Infra Projects

Ronald grew up in an international environment: the basis of his career in integral projects. From his design and engineering background, he has grown into the project management of large, complex projects.

Business Unit Director Ronald De Geus Ballast Nedam Infra Projects
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