Experimental study on the bending performances of shear‐resistant tightly keyway‐assembled composite slab

Abstract This paper proposes a novel shear‐resistant keyway tight joint connection composite slab aimed at minimizing surface crack propagation of the composite slab, so as to improve the bearing capacity and ductility of the composite slab. Five composite slab specimens were prepared and subjected to full‐scale bending tests and numerical simulations to assess bending performance, including cracking load, ultimate bearing capacity, crack propagation and distribution, and failure characteristics. The investigation compared non‐keyway tightly assembled composite slabs, L‐shaped keyway tightly assembled composite slabs, and shear‐resistant keyway tightly assembled composite slabs. The bending bearing capacity of shear‐resistant keyway tightly assembled composite slabs substantially exceeded that of non‐keyway and L‐shaped keyway tightly assembled composite slabs. A finite element model, demonstrating high consistency with experimental findings, was developed, and its efficacy in simulating composite slab bending performances was validated. Furthermore, parameter analysis of the finite element model revealed that enhancing the diameters of additional steel bars and depths of shear‐resistant keyways can effectively improve composite slab bending bearing capacity, whereas the plane area of shear keys exhibited minimal influence on overall bearing capacity. Through comparative analysis on the flexural performance of the composite slabs with different slotted forms, the rational design of the groove splicing joint of the new shear keyway composite slab is determined, which provides a theoretical basis for the application of the new type of composite slab in engineering practice.