Development of the national technical approval for carbon and textile reinforced concrete construction products and methods
Construction research and development work can often result in new types of construction products / methods, for which there are originally no technical rules or they differ from the existing technical rules. The usability of such unregulated construction products / methods is in turn made possible by the issue of an individual case-by-case (project-related) approval (“Zustimmung im Einzelfall” – ZiE) and the national technical approval (“allgemeinen bauaufsichtlichen Zulassung” – abZ). The national technical approval (NTA) in Germany has been issued since 1968 by the German Institute for Construction (Deutsche Institut für Bautechnik – DIBt). The national technical approval defines the relevant building control properties of a construction product, as well as the areas of use and aspects or use, transport, storage, labelling and confirmation of conformity. In addition, a type approval can be integrated into an NTA, insofar as the aspects of jointing, planning, design and execution are to be regulated. Thus, the relevant trends can be used to deduce future focal research areas of application and specialist fields concerning carbon and textile reinforced concrete construction.
Figure 1 represents the development in the number of NTAs for carbon and textile reinforced concrete construction, which is based on the Approval shop of the DIBt. In combination with search terms regarding “concrete and textile reinforced concrete”, since the year 2000 a total of 20 NTAs have been published, whose validity period extends to the present day. It is conspicuous that, in this context, the portfolio has quadrupled since the beginning of the C³ project in 2014.