New “Edeka Arena” exhibition hall in Offenburg
A new exhibition hall is being added to the exhibition grounds in Offenburg. This is characterised by its graceful design and extreme wall heights. For the concreting work, the contractor relied on the elements of NOE formwork technology.
A new building of approximately 7,000 m² is currently being built at the southern end of the Offenburg exhibition grounds, directly adjacent to the approximately 15-year-old Baden Arena and forming the southern entrance. The building consists of three structures of different heights and impresses with its delicate design. Since the premises are to be used not only for trade fairs but also for other events, the planners attached great importance to maximum flexibility. Accordingly, they designed the foyer with a large glazed façade. The actual hall with a floor area of almost 5000 m² is characterised by absolutely opaque walls and ceiling surfaces.
Hall construction
The enormous room heights of the building are impressive. They were also the ones who repeatedly presented the contractor, Rendler Bau from Offenburg, with great challenges. The exhibition hall itself has a clear height of about 19 metres. To build it, those responsible decided on two different methods: Three walls were constructed with precast reinforced concrete columns and precast reinforced concrete hollow wall elements. The fourth foyer wall – part of the bracing core with a niche for the grandstand – was conventionally constructed in cast-in-place concrete. The renowned construction company Rendler Bau relied – as it has for over 25 years – on the systems of NOE-Schaltechnik. The construction company has around 2500 m² of the classic NOEtop wall formwork with plastic formlining in its own inventory. One reason for this is its durability – all frames and profiles are hot-dip galvanised inside and out. In addition, the system is extremely versatile and can be used equally well as frame and beam formwork. The contractor has an open choice of tie rod positions with this system. All panels have a uniform profile thickness and are equipped with cast corners. The elements are available in many different sizes – for example in the XXL version. This has a height of 5.30 m and a width of 2.65 m, making it one of the largest formwork panels on the market. As it enables areas of more than 14 m² to be formed in a single operation, it is tailor-made for efficient and economical working. An advantage that the Rendler company also used throughout the lower area of the exhibition hall.
Wall to the foyer
However, the wall of the hall, which directly borders the foyer, was a much greater challenge for the company carrying out the construction work: Since the loads of the foyer staircase are structurally very demanding, this wall could not be produced in the same way as the other three. Instead, the contractor first had to erect a 10.33 m high wall slab, then construct the ceiling offset above the grandstand bearing and finally build the approx. 9 m high remainder of the wall including the edge beam. However, it is not quite so easy to safely form such large wall surfaces with a height of up to 10.33 m. To ensure a hazard-free solution, the push-pull props for the 10.33 m high lower wall section were placed inside the hall – so they could be fixed to the ceiling at the base. They were also stabilised with the help of heavy concrete blocks. For the formwork work of the upper 9 m high section, the Rendler site team pulled up the NOEtopS platform and placed it on the heavy-duty scaffolding bracket platform attached to the outside. The NOEtop S platform is a supplement to the NOEtop system and has the advantage that all working platforms, access ladders and push-pull props are mounted directly on the formwork panels. Thanks to these elements, the formwork stands almost by itself. The NOEtop S platform arrives on site ready for use and only needs to be unfolded. It is available in widths of 1.325 m and 2.65 m and can be perfectly combined with the normal NOEtop formwork, offering the great advantage of making the work extremely safe.
Bracing
The trade fair construction is very high and has hardly any bracing walls. This repeatedly confronted the Rendler company with tasks that rarely occur in construction. For example, 4.5 m high steel truss elements on the 19 m high columns provide the horizontal bracing of the building. As a result, the walls between the columns were not sufficiently braced until the roof construction was complete.
Earthquake resistance
Offenburg is located in earthquake zone 2. This means that earthquakes are quite possible. As this had to be taken into account in the structural requirements, the start of construction was unexpectedly delayed by about half a year. Nevertheless, with a lot of commitment and the active support of NOE-Schaltechnik, Rendler Bau managed to meet the deadline. A proud achievement given these various tricky construction tasks.