Mombarg Beton (Beldert Beach observation tower)
Legos for advanced users
Complex structure entirely in concrete
A unique landmark made possible through the use of an ingenious construction method, the bathing lake at Beldert Beach in Zoelen offers something for everyone. Wonderful water for swimming, a lounge club, and various activities such as beach volleyball, low ropes, WipeOut, and now even a fantastic 20-metre observation tower. Beyond the look-out point, the towers have catering facilities, three climbing walls, and the longest zip line in the Netherlands measuring 300 metres. The new landmark is made entirely of concrete, which was only possible through the use of an ingenious construction method with prefabricated concrete components.
Made entirely of concrete
Thanks to the spectacular designs of three other observation towers, one of which was awarded the Benelux Trophy, Ateliereen Architecten from Eindhoven also became involved in the project. 'The design is based on the experience of the visitor. Essentially, it is a staircase leading up to a look-out point, but we always try to make something special out of it,' according to Maud Nieraeth-van Banning, Ateliereen Architecten owner and architect. 'The customer, Holland Evenementen Groep, was immediately enthusiastic after viewing the first design. We decided to make the structure entirely in concrete because of its attractive, robust character and the option to use the walls as a climbing wall.'
Prefabricated or in situ?
The search for the right working method for this structure was strenuous. Prefabricated or in situ? Maud explains: 'Because everyone advised us against using prefabrication, we first decided to go with in situ. But the quotes for this were all far too high.
Except the quote submitted by contractor Van Arnhem. They wanted to work with prefabrication because of the extraordinarily complex form, which would raise all sorts of complications in situ. They already had extensive experience with prefabrication construction specialist Mombarg Breton. For their part, Mombarg Breton quickly submitted a viable and feasible proposal to build the towers from prefabricated components. This appeared to be a better solution not only from a costs point of view, but also because of aesthetic considerations. The execution can be sleeker, more attractive, and more spectacular than in situ!
Complex designs broken down into separate components
Mombarg Concrete completely re-modelled the architectural 2D design in 3D in Autodesk Revit. 'The combination of their expertise with concrete and our aesthetic vision led us to a construction with separate components that seamlessly connected at the correct boundary heights and planar intersections. Our design was left intact, while they were able to make it feasible.'
Frank van der Drift, Works Manager of Mombarg Beton, adds: 'For the engineering and manufacturing, we selected eleven prefabricated concrete rings stacked on top of each other that had fixed widths, but varying length and height measurements. Although these components are different, they will be poured using only one form which can be changed.'
A stable construction is essential
While the architect naturally wants to maintain the unusual shape with angled surfaces and edges, the concrete engineer would prefer the tower to be as straight as possible for the sake of simplicity and stability. Frank continues: 'The latter consideration was particularly important in the structural design for this project. The tower had to stand independently, and not have any tendency to fall over due to its form.'
To meet this requirement, Mombarg Beton expanded Revit with the TheModus Center of Gravity module developed by Cadac Group. 'Thanks to this powerful tool, adds Frank, 'we were able to determine the tower's centre of gravity virtually – for the entire structure, the lower or upper half, or even the individual elements. This enabled us to precisely determine whether the tower was balanced and stable throughout the design phase. Not only did this result in a better quality structure, but the construction also proceeded considerably faster and with fewer problems. Without this, TheModus module our design engineers would have had a tremendous amount of additional work, performing very complicated centre-of-gravity calculations, which would have also greatly increased the chance of errors!'More about TheModus Center of Gravity
Production drawings in no time
Mombarg Beton uses TheModus Center of Gravity and TheModus Documentation. Frank continues: 'Normally we model a structure, in this case a tower, in Revit where we take out the concrete elements we produced to create views and production drawings.
We used to do it manually, which was incredibly time consuming, and even with revisions and changes, this always created a lot of work. Fortunately, that can now be done with a few simple mouse clicks. While preparing a drawing board can take an average of 15-20 minutes per component, it now takes us just five minutes. TheModus Documentation automatically takes out the sheets from the Revit model. Just think of the time savings this provides with a building composed of roughly 400 components!'Read more about our TheModus Suite