First practical application of prestressed carbon concrete: school sports hall in Dresden

As part of a real-world transfer pilot project, a roof structure made of prestressed carbon concrete was built for the first time in Dresden under real construction and usage conditions. For the new construction of a single-span sports hall at the 49th elementary school (extension to an existing hall; roof with PV system and extensive greening), a completely prefabricated roof system made of prestressed carbon concrete trusses and thin, prestressed carbon concrete slabs was implemented. Based on a preliminary study and a component catalog, carbon concrete elements were specifically used where there was a demonstrable added value compared to conventional reinforced concrete; In addition to facade elements (facing shell), the roof structure in particular proved to be suitable due to lower fire protection requirements. Due to the span of 16.4 m and the high roof loads (PV system, green roof), an economical and serviceable design was only possible by means of prestressing. As there were no building regulations for prestressing with carbon reinforcement at the time, the project was implemented on the basis of extensive preliminary investigations, a wide variety of design approaches, targeted experimental tests, and several approvals in individual cases/project-related type approvals. The project demonstrates the potential of combining carbon concrete and prestressing in terms of material savings, durability, and resource efficiency, while at the same time achieving very slim cross-sections and a high degree of prefabrication under real construction conditions. At the same time, significant challenges were identified, in particular manufacturing tolerances for filigree components, stability verification during transport and assembly, and the development of suitable connection details. Overall, the project provides a solid basis for the further transfer of prestressed carbon concrete into practice and shows starting points for more economical and efficient application in the construction industry in the future