News from Research and Development

Compared to conventional concrete, which is typically characterized by its compressive strength, post-cracking tensile strength becomes crucial when steel fiber reinforced concrete (SFRC) is used. One key factor that influences the post-cracking behavior of the material is the orientation of the fibers. However, this can only be controlled to a limited extent during manufacturing.

Therefore, at the Chair of Concrete and Masonry Structures at TUM, a new method has been developed for aligning steel fibers. Based on comprehensive data analysis, a computational approach was calibrated to reliably predict the fiber orientation after the alignment process. This allows the specific consideration of fiber orientation already during the design stage.

The method is well suited for precast concrete production, such as the manufacture of segments for mechanized tunneling. At the longitudinal joints of the segments, occurring splitting tensile forces often prevent the use of pure SFRC, necessitating conventional reinforcement. By aligning the fibers locally and in the correct direction at the joints, the required post-cracking tensile strength can be achieved, allowing the benefits of steel fiber reinforced concrete to be fully utilized.

We have filed a patent application for this innovative alignment method in collaboration with BayPat. Please find the technical proposal attached. We are currently seeking partners in formwork and segment formwork technologies to take the next steps toward a first “real-world” application. For more information, feel free to contact Maximilian Kronau (maximilian.kronau@tum.de).