New construction of KSC stadium with Isokorb and Stacon

The long-established club has been waiting for this for a long time: with the construction of the new BBBank Wildpark stadium, the professional football team of Karlsruher SC will finally have a modern, attractive sports facility offering space for over 34,000 spectators. While an innovative supporting structure of Y-shaped columns, which back-anchors the stadium roof, lends the structure a distinctive and unmistakable exterior appearance, Schöck products play the big game in the interior. Schöck Isokorb and Schöck Stacon minimize thermal bridges while at the same time ensuring stability and a reliable transfer of loads.

Constructed in a step-by-step process since the end of 2019 without interrupting play, the stadium rises above the green bulwark of long-standing tradition and impresses with its coherent and esthetically appealing architecture. A bird’s eye view of the single-tier stadium shows the spectator circuit in accessible design, which has now moved closer to the pitch and runs around the “lion’s den” as an architectural band above the tenth seating row.

Ibbenbüren-based architectural firm Agn Niederberghaus & Partner used the existing topography in the design of the spectator stands. The lower seating rows nestle up to the slope that forms the surrounding earthen rampart. The spectator circuit sits directly on the rampart for the most part but simultaneously functions as the basement ceiling in the area of the main building. Thermal separation therefore needed to be ensured not only in this area but also in the box balconies two levels above that are directly connected to the uppermost circuit.

Weakness in energy efficiency: thermal bridges in stadiums

Although football matches are outdoor events, the issue of thermal bridges in stadiums is a complicated one for precisely this reason: non-insulated spectator stands are a weak spot in terms of energy efficiency wherever they meet heated buildings with locker rooms, VIP lounges, club rooms, functional-rooms or catering facilities.

In these areas, there is a risk of thermal bridges. Unless these are minimized by means of
appropriate insulation measures, condensation forms on the surface as a result of the differences in temperature, which in turn leads to moisture and, over time, to structural damage.

Design support provided by Schöck

Manfred Klawonn from Dortmund-based design office Assmann Beraten + Planen relied on the Schöck Isokorb XT as a load-bearing thermal insulation element for the thermal separation at the parapet and ceiling connections. The structural engineer has been working with Schöck products for many years, appreciating not only the reliable product quality but also the numerous digital tools offered by the manufacturer, for example, for design purposes.

When a change in the plan to lower the ceiling in the area of the lower spectator circuit required an additional floor structure that resulted in a massive increase in weight, it was possible to quickly check whether sufficient load-bearing capacity could, in principle, still be guaranteed using the available design tools. Thanks to the high load-bearing capacity of the Schöck Isokorb, however, this could be achieved by simply reducing the element spacings.

Flexible when faced with special challenges

The highest priority in the new construction of Karlsruhe’s football stadium was generally given to issues of load-bearing capacity and structural stability. As the city of Karlsruhe is located halfway along the Upper Rhine Graben, the requirements for seismic zone 1 apply.

Special solutions needed to be found in some areas in order to safely transfer excessive loads. In some cases, the Isokorb XT type H was installed rotated through 90 degrees, for example, in order to absorb shear forces. “We have installed the Schöck Isokorb so many times that we can use it creatively and know what is possible. That enables us to always find solutions even for unusual challenges,” explains Manfred Klawonn. Another strong point, according to him, is the comprehensive range of products, which offers numerous options.

Schöck Stacon for the reliable connection of walls

Another challenge was connecting the ceiling slabs to the interior walls on the lower levels: the construction company decided at an early stage to use a non-load-bearing design, instead connecting the walls to the ceiling slab under a no-load condition. This resulted in a flexible floor plan and allowed the interior wall layout to be determined at a later date.

The element walls were installed with a 3-cm wide joint below the ceiling. At the site of connection, the Schöck Stacon LD shear dowel stabilizes the interior walls while at the same time preventing the transmission of forces from the ceiling. Stacon thus provides a simple and reliable solution for connecting the structural components adjacent to the joint – without requiring additional structures such as brackets or double walls.

Quality on all levels

These are advantages that count for Manfred Klawonn, since they offer real added value. He benefits not only from sophisticated products optimized for the intended application, but also from their high quality, structural performance, safety and on-time delivery. “We are happy to recommend Schöck products to our clients,” he concludes, adding: “Not only do we have a lot of experience with them, but we can always rely on Schöck’s technical support when more complex problems need to be solved.”