Overlap effects of one-end welded box-profile shear connectors on interlayer shear behavior

Steel-concrete-steel (SCS) sandwich structures consist of two steel faceplates and a concrete core, interconnected by mechanical shear connectors . There is a research gap regarding the lack of comprehensive understanding of the overlay effect on shear behavior of single-sided connectors in SCS structures, as well as the determination of the optimal overlap ratio to improve the performance and resistance of these structures.This study addresses the overlap effect of one-end welded one-end embedded shear connectors, which are essential for managing thickness limitations in these structures. The research introduces a new type of shear connector: the one-end welded one-end embedded box-profile (BP) connector, aimed at reducing construction costs. Fifteen specimens were fabricated and subjected to push-out tests to evaluate their shear behavior. Key factors analyzed included the width of the BP and the ratio of the BP overlap to the core thickness . Results indicate that these BP connectors enhance slip capacity, stiffness, and shear strength , particularly as the BP width increases. An optimal overlap-to-thickness ratio of 0.25 was identified, which maximizes shear strength and improves load-slip characteristics. Additionally, reducing the overlap ratio of the shear connectors from 1 to 0.25 results in a 29.5 % increase in ultimate strength. Finally, a modified model was proposed to predict the load-slip behavior of BP connectors, utilizing shear strength calculations based on channel shear connector codes and introducing a modification factor of γ v = 1.3 for more accurate predictions. This study advances the understanding of shear connectors in SCS sandwich structures, offering valuable insights for engineers.