Flexural behavior of prefabricated high-strength steel-concrete composite beams with steel block connectors

To study the flexural behavior of high-strength steel-precast concrete slab (HSS-PCS) composite beams with steel block shear connectors (SBSCs), seven HSS-PCS beam specimens subjected to a single concentrated load were tested, considering the parameters of concrete strength, steel strength, and shear connection degree. Through this experiment, the primary specimen information of vertical load, deflection, mid-span section strain, and interface slip were established. The HSS-PCS composite beam with steel block shear connectors has good overall working performance with high bending capacity and stiffness, and three failure modes are recorded including cracking at the tongue and groove joints, crushing of mid-span concrete slab, and failure of shear connections. The composite beams show a high degree of brittleness under these three failure modes, which should be considered in practical design. The existing design theory and standards are generally suitable for predicting the bending capacities of the novel prefabricated composite beams, in which the Eurocode 4 is slightly conservative, while the Chinese design specification has relatively good prediction results for the composite beams with partial shear connections.