The global demand for carbon fibers is increasing on an annual basis. As demand for carbon fibers increases, the useful life of components made of carbon from the automotive or aviation industry is also reaching its limit. Consequently, end-of-life components may serve as a potential source of reusable and recyclable carbon fibers (secondary fibers). The recovery of carbon fibers, as well as the subsequent processing of these fibers into semi-finished products for the construction industry, has yet to be achieved on an industrial scale, with significant challenges remaining. The production of yarns and nonwovens, as well as subsequent processing into grids, rebars, and sheets, is either planned or has already been implemented. In order to conduct an initial assessment, it is recommended that yarns produced from short fibers be evaluated for their stress-strain behavior. Furthermore, the process parameters for the production of nonwovens using warp knitting technology or direct yarn placement must be adapted to the prepared material. This will provide a foundation for future industrial processing of secondary fibers into semi-finished products. In addition to its application in the construction industry, the research project encompasses the production of nonwovens and their subsequent processing into panels for the use in the automotive and aviation sectors. The paper presents experimental investigation of semi finished products made of recycled carbon fibers. Experimental setups have been developed to test bundles of fibers in terms of carbon yarns. The mechanical properties of these semi-finished products are required for the use of carbon reinforcement in composition with concrete.