Static shear performance of small diameter short stud connectors embedded in UHPC

Steel–thin UHPC (Ultra-High Performance Concrete) composite structures have emerged as a promising solution in engineering due to their superior mechanical properties and durability. This study addresses the research gaps concerning the static shear performance of small diameter short stud connectors in steel–thin UHPC composite structures through a combination of experimental tests and numerical simulations. The failure process and mechanisms are analysed. Key findings reveal that stud root fracture and UHPC crushing at the stud root are the primary failure modes. The stud diameter significantly impacts shear capacity, followed by UHPC strength, stud longitudinal spacing, and stud aspect ratio, while the UHPC slab thickness has a minimal effect. Notably, when the stud longitudinal spacing exceeds 6 times their diameter, its effect on shear capacity becomes negligible, as does the influence of the stud aspect ratio beyond 3.1. Shear stiffness is primarily influenced by stud diameter and UHPC strength. A new formula for shear capacity, which considers stud longitudinal spacing and aspect ratio, has been developed with high predictive accuracy. Furthermore, a load–slip curve prediction model, considering stud diameter, has been formulated, aiding in their design and application.