Speaker: Dr. Penzel Paul

Carbon reinforced concrete (CRC) is characterized by its corrosion resistance, material efficiency, and high load-bearing capacity. To fully leverage the potential of high-performance carbon reinforcement structures, load-specific and component-adapted textile reinforcement structures are essential. For retrofitting and reincoring planar structural elements, biaxial grid structures and rebars have been established as effective solutions. However, for three-dimensional, more complex geometries, these reinforcement structures often require complex subsequent forming processes and often result in overdimensioning and therefore an inefficient use of the carbon reinforcement strucure. For the tailored and efficient reinforcement of components with complex 3D geometries, such as hollow-core slabs and beams, load-path-based reinforcement structures are needed, according to the biological principle of "form follows force." A particularly promising reinforcement structure is the so-called “Netzgitterträger”. First Netzgitterträger were fabricated manually as well as using advanced multi-axial warp-knitting technology with specialized warp thread manipulation and shaping systems for hollow-core slab systems. This reinforcement structure, consisting of branched and alternating, diagonally offset roving paths with overlapping edge area, enables high material efficiency and advantageous anchorage of the reinforcement. This principle of branched and merged reinforcement paths can also be found in botanical structures. Thus, biologically inspired load-path designed reinforcement layouts can also be applied to slab systems such as T-beams. For high performance and more complex, branched reinforcement structures, robot-based automated yarn deposition is particularly suitable. This paper presents the Netzgitterträger principle through examples of slab and beam systems, selected experimental results on load-bearing behavior and productive manufacturing processes for the fabrication of complex, biological inspired reinforcement structures.