Load‐bearing and local bond behavior of two‐span concrete slab strips with hybrid steel/ <scp>CFRP</scp> reinforcement

Abstract Utilizing brittle components in structural concrete challenges state‐of‐the‐art verification procedures based on limit theorems of the theory of plasticity. Unresolved questions regarding deformation capacity, force redistribution, and the influence of generally unknown self‐equilibrated stress states impede universally applicable verification frameworks for concrete structures without regions that can fully plasticize. A prerequisite for establishing such frameworks is a detailed understanding of the mechanical behavior, the interaction of brittle and ductile reinforcement components and the impact of self‐equilibrated stress states. This paper investigates the structural behavior of two‐span concrete slab strips with hybrid steel/CFRP reinforcement, that is, the combination of conventional ribbed steel reinforcing bars (ductile elements) with sand‐coated CFRP rods (linear elastic, brittle elements). The study focuses on (i) the global load‐bearing behavior, (ii) the influence of self‐equilibrated stress states, and (iii) the local bond behavior, which are all discussed regarding initial (backbone) and cyclic loading, respectively. Statistical evaluations of nominal bond shear stress as a function of slip and reinforcement strains—all obtained from Distributed Fiber Optical Measurements—allowed for reliable quantification of the bond behavior and provided consistent insight despite considerable scatter. All data gathered in the presented tests are published open source together with a separate data repository guide.