Great flexibility and freedom of form

50,000 m2 of wide slab floors for residential towers The Orchard

With the construction of new construction project The Orchard, new life will be breathed into the Rijswijk shopping center De Bogaard. The partly covered shopping area from the 60s no longer meets current requirements and is undergoing a drastic metamorphosis, combining shopping with living and working. The construction of The Orchard I and The Orchard II will add no fewer than 509 affordable and sustainable rental apartments and a commercial plinth to the area. Commissioned by ERA Contour, Van Muijen Betonbouw is realizing the shell work for both towers, from concrete floors and concrete walls to prefabricated balconies, stairs and HSB elements. ’In total, we are processing about 20,000 m3 of concrete in both residential towers,“ says Douglass Dall, work planner at Van Muijen Betonbouw. ”An important part of this is the approximately 50,000 m2 of wide slab floors from De Hoop Pekso.“

Van Muijen Betonbouw and De Hoop Pekso can fall back on more than ten years of partnership. In almost all structural projects with wide slab floors that the concrete builder realizes, floors from De Hoop Pekso are applied. So too in The Orchard in Rijswijk, where the situation was complex. “The residential towers were built on a multi-story plinth with a parking garage and stores,” says Dall. “In this substructure we had to deal with various level differences, corners and slopes. Tunnel construction, where the walls and floor floors are realized in one pour, can create complications in that case. By working with wide slab floors, this is cleverly overcome.”

Reinforced system floors

De Hoop Pekso's wide slab floors are poured with traditional concrete, incorporating the necessary reinforcement. “The floors are composed of a concrete shell of 50, 60 or 70 mm, which are provided with constructively required plate reinforcement and continuous lattice girders. In addition to their constructive task, these lattice girders also function directly as lifting points,” says Carlo Molenaar, North-West Region regional manager at De Hoop Pekso. “The floors are manufactured in our own factory in Oosterhout and under the best climatic and working conditions.” Floors and walls are essential parts of the construction and of the building as a whole, he emphasizes. “In preparation, we therefore closely coordinated the floor-wall connections together with Van Muijen Betonbouw, cleverly eliminating clashes and failure costs during execution.”

Permanent engineering teams

”What is very pleasant about working with Van Muijen Betonbouw is that our structural engineers always work together with a regular engineer,” Molenaar says. “This benefits the engineering process considerably. We can read and write with each other and half a word is enough.” Dall agrees and says, “The cooperation within the team is natural and the communication is friendly, making the threshold for asking questions as low as possible. This makes sparring pleasant and ultimately ensures the desired results.”.

Approximately four thousand unique floors

Construction of The Orchard began in May 2023. Just after the construction period, the last wide slab floors were delivered, and the shell construction was completed in September. “A total of about four thousand wide slab floors were processed,” Molenaar knows. “All these floors are unique in composition and individually engineered by us. For example, penetrations have direct consequences for the structural value of the floor, which must then be met with additional reinforcing steel.” The wide slab floors were transported in batches of 160 to 200 m2 and on a flatbed trailer to Rijswijk, where they were laid according to a specific laying sequence. Says Dall, “Thanks to the beveled longitudinal edge, the floors can only be laid one way.”

Great freedom of form, neat connection

Another big advantage of the wide slab floors of De Hoop Pekso is their great flexibility and freedom of form, says Molenaar. “Piping can easily be included in the compression layer, while sloping sides guarantee a good mutual connection. In addition, our wide slab floors have very good soundproofing properties and meet the fire resistance requirements of 120 minutes very well. Thanks to the smooth underside, the floors are immediately ready for spraying.”