Innovative Special Buildings: Wangen Tower and Hybrid Flax Pavilion at the Holzbau-Offensive BW conferences
On September 3, 2024, researchers from the Institute for Computational Design and Construction (ICD) at the University of Stuttgart presented the Wangen Tower and the Hybrid Flax Pavilion at the Holzbau-Offensive BW conference at the Landesgartenschau in Wangen. In addition to presentations that examined planning and production in detail, the focus was on discussions with the specialist audience and a tour of the two buildings. The Wangen Tower and the Hybrid Flax Pavilion were developed at the Cluster of Excellence Integrative Computational Design and Construction for Architecture (IntCDC) at the University of Stuttgart and opened at the Wangen Landesgartenschau at the end of April.
The Wangen Tower and the Hybrid Flax Pavilion are not only real highlights for visitors to the Landesgartenschau in Wangen, but also deal with a wide range of research aspects relating to sustainable construction and building production. David Stieler and Christoph Zechmeister, research associates at the ICD, therefore explained to the specialist audience how the Co-Design method is used to develop digital material and construction systems in research using computer-based design and robotic processes.
Wangen Tower
Self-shaping wood makes use of the natural deformation effect when the wood dries. Although the elements of the tower look like free forms, they are created by intersecting inclined cylinders. Their hyperbolic shell structure creates a geometrically determined high rigidity that does not require any additional reinforced concrete. Only the construction of the visitor platform is used for additional bracing.
The expert audience was particularly impressed by the further development of the Wangen Tower compared to its predecessor – the Urbach Tower. As a sculpture, this had to meet significantly lower structural requirements. Due to its height of around 22 meters and its exposed geographical location, the accessible Wangen Tower has to withstand high wind loads and required a project-related approval by the MPA Stuttgart. In contrast to conventional residential construction, where the timber structure is occasionally reinforced with steel and concrete, here the timber structure provides lateral support for the steel spiral staircase.
Hybrid Flax Pavilion
For the first time, flax fibers were combined with wood to form a hybrid system. In analogy to a simply supported beam with compression and tension zones, compressive forces are absorbed in the upper area of the wooden plate in the “middle of the beam” and mainly tensile forces are absorbed in the bottom fibre component. This resulted in load-bearing elements with long spans of over eight meters, which save around a third of the wood compared to massive roof plates. The cross-laminated timber plates are only 120 millimeters thick and arranged in a circular pattern, alternating between those with and without flax bracing.
Many parameters play a role in coreless filament winding in order to achieve the best possible result for the load-bearing elements: Not only the thickness of the fiber bundles, but also the tension during winding, the amount of resin, the structure of the winding frame and the sequence of the different fibre layers must be coordinated so that the fibres lie compact on top of each other and bond to form a stable, load-bearing component.
About the event series
On behalf of the Holzbau-Offensive BW and in cooperation with Landesgartenschau Wangen GmbH, proHolzBW is organizing several specialist conferences on innovative timber construction projects that will be presented at the Landesgartenschau Wangen 2024.
