A team from the universities of Konstanz, Stuttgart and Karlsruhe, together with proHolz Baden-Württemberg, has taken on the task of finding a new use for the concrete formwork from the construction site of the new main railway station in Stuttgart. As part of the research project "Stuttgart 210 weiterdenken - weiterbauen!", possibilities for reusing the concrete formwork are being investigated and then implemented in various real laboratories.
The new underground through station in Stuttgart is the centerpiece of the Stuttgart-Ulm rail project. Complex concrete formwork made of cross-laminated timber is used for the construction of its unique roof structure consisting of 28 goblet supports. Parts of the formwork are converted into wood-fiber insulation material after use, while the rest is sent for thermal recycling. The volume of all formwork elements amounts to a net total of approximately 5,000 m³ of cross-laminated timber - a large and previously untapped potential.
In its research project, an interdisciplinary team of architects and engineers from the participating universities HTWG Konstanz, HFT Stuttgart and HKA Karlsruhe, together with the project partners proHolzBW, ZÜBLIN Timber GmbH and Ed. Züblin AG, is identifying re-use options for the formwork elements as building components.
Future strategies for the high-quality use of demolition or waste material as well as raising awareness for the adaptation of design decisions to existing resources are among the stated goals of the project. Instead of adapting material requirements to predefined designs, the researchers believe that the design process should be based on existing resources. Functional, design, construction and structural engineering options are being determined for various designs, a life cycle assessment procedure for re-use building components is being developed and the necessary legal framework for 1:1 applications is being researched.
The project is funded by the Ministry for Rural Areas and Consumer Protection Baden-Württemberg (MLR) as part of the Holzbau-Offensive Baden-Württemberg. proHolzBW is responsible for public relations and coordination. The company ZÜBLIN Timber GmbH and Ed. Züblin AG, from which the formwork elements were manufactured, supports the research project as a practical partner by providing the digital joinery plans.
From the Faculty of Architecture and Design, Prof. Andreas Kretzer is involved in the research project with the topics of determining the fundamentals, presenting the research content and working on design-related topics. After completion in 2024, the results will be presented to the public in an exhibition.
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Although the available concrete formwork is a special case due to its specific geometric shape, through its use in various real laboratories we are trying to gain transferable knowledge about the early consideration of a later reuse of temporarily used elements as building components and the related building law issues.