Promotion Enrico Baumgärtel

On March 13, 2026, Enrico Baumgärtel successfully defended his dissertation 👨‍🎓 entitled "Experimental investigation of the tensile strength behavior of semi-finished products made of recycled carbon fibers". The event took place in the Beyer Building of TU Dresden.

Abstract:

Carbon-reinforced concrete has been an integral part of the construction industry for over 20 years. Building on intensive basic research, carbon concrete, a composite material, has been implemented in an increasing number of construction projects in recent years. In addition to reinforcement, continuous carbon fibers are being used in ever-increasing quantities in many areas of life. Both the automotive and aviation industries are processing larger quantities of carbon fiber. One disadvantage of using carbon fibers is that the composite is difficult to recycle. Various processes can recover pure carbon fiber from the composite for reuse. However, these processes shorten the continuous fibers. One potential application for processed, shortened carbon fibers is their use in semi-finished products that can be reused in construction in the form of reinforcing rebars and grids (reinforcing mesh). When used with concrete, it is essential to understand the material properties of these semi-finished products, as they may differ from those of semi-finished products made from primary fibers. This thesis makes an essential contribution to this topic. First, it presents the various preparation methods of carbon fiber-based composites and explains their further processing into semi-finished products. Then, the tensile tests on the semi-finished products are presented. Within the scope of the work, yarn and rebar tensile tests were prioritized. In addition to investigating semi-finished products made from secondary fibers, reference tests were carried out on those made from primary fibers. In addition to determining tensile strength, stress-strain behavior, and stiffness were investigated. Based on these tests, CT scans were performed on selected semi-finished products to determine fiber orientation, defects, and porosity. These results were then used to develop a method for dimensioning semi-finished products made from secondary fibers. This design methodology will form the basis for further research. In addition to describing a design method, the results determine initial bandwidths for individual factors. The results obtained in this study allow for an initial assessment of the material behavior of semi-finished carbon fiber products under tensile stress. Additionally, these findings lay the groundwork for future research on semi-finished products made of secondary fibers.

Dear Enrico, we would like to take this opportunity to wish you every success in your future scientific career and all the best for the future. Good luck 👍🥳