80 / 2022-04-15 03:20:11

Experimental Investigation of Bolted Shear Connectors for UHPC-Formed Composite Beams

high strength steel,bolt shear connector,ultra-high performance concrete,composite beam,push-out tests

Composite steel-concrete beams have been widely applied in the construction of bridges and buildings due to their outstanding structural performance. Compared with the composite beams made of conventional concrete, ultra-high performance concrete (UHPC) can be applied to form the structures to improve the resistance, durability and sustainability of the composite beams. To realize the desirable structural strength and stiffness, shear connections play an important role to effectively transfer the internal shear forces between the UHPC and steel components. Conventional stud shear connections are welded permanently to the steel beams, leading to high inconvenience for dis-assembling and reuse of the structural components.     

High strength bolted shear connectors that enables to easily deconstruct the composite beams for sustainable rebuild and provides higher strength than stub connectors were investigated experimentally in this study. Push-out tests were conducted on steel-UHPC composite beam elements with bolted shear connectors. The ultimate strength, load-slip characteristics and failure modes of the specimens with different parameters related to shear connector arrangements were reported and discussed. Furthermore, the ultimate strengths were also compared with those estimated based on existing standards or the methods proposed in literature and the applicability of those methods for predicting the strengths of the high strength bolted shear connectors embedded in UHPC slabs was discussed.