Fabrics made of high performance, non-corrosive endless fibers, embedded in a cementitious matrix, can be advantageous over common steel reinforced members. The performance of textile reinforced concrete (TRC) resp. carbon concrete composites was demonstrated by several built examples. An obstacle to a broad application of this building material is the lack of regulations and codes. With a first general building approval, the building with TRC should be made easier. The approval is valid for bending strengthening inside buildings. This article introduces the basic research on strengthening of slabs, describes the scientific investigations that were necessary to obtain the approval, as well as the application conditions.