Experimental study on bending resistance of steel-UHPC composite slabs

Abstract

The local cracking problem of steel-UHPC composite slab structure layer under negative bending moment is a basic research topic for the application and development of this new type composite bridge deck structure system. Combined with the performance of UHPC, the mechanical behaviour of composite slab before ultimate load was analysed by designing a pure bending test model, and the mechanical indexes such as cracking load and ultimate load were obtained. The results show that the reinforcement and the combination effect can effectively limit the development of tensile crack in UHPC layer and improve the bearing capacity of the slab. The reinforced steel-UHPC composite slab ears good ductility. The material properties of UHPC should not be ignored in the analysis and calculation of mechanical properties of composite slabs. The combined effect can limit the development of tensile cracking and change its failure mode of the UHPC layer. The thickness of longitudinal reinforcement protective layer of steel-UHPC composite slab can significantly affect its flexural behavior. The application range of the equivalent section method based on linear elasticity is limited, and it is necessary to develop the analysis and calculation method that can accurately reflect the cooperative working effect of each member of the steel-UHPC composite plate.