Experimental study on flexural and punching shear performance of ribbed UHPC bridge deck panels

Abstract:

Ultra-high performance concrete (UHPC) has been widely used in bridge engineering in recent years due to its superior mechanical properties and durability. To reduce costs while maintaining the high performance of UHPC, this paper investigates the mechanical properties and failure characteristics of ribbed UHPC bridge decks reinforced with 1.2% volume fraction of straight copper-plated micro steel fibers, under different reinforcement conditions (ordinary steel bars and high-strength steel bars), through bending and punching shear performance tests. The results indicate that UHPC ribbed bridge decks exhibited good ductility and flexural failure modes under different reinforcement conditions. The use of high-strength rebar significantly improved the ultimate bearing capacity, fully utilizing the material properties of the high-strength reinforcement. In terms of punching shear performance, the UHPC ribbed bridge decks showed a punching-flexural failure mode with substantial ductility. High-strength rebar increased the punching shear capacity by approximately 25% at the same reinforcement ratio, but further increases in reinforcement ratio had limited impact on bearing capacity. The findings demonstrate that using lower volume fractions of steel fibers and high-strength rebar can reduce costs while maximizing the superior properties of UHPC and high-strength steel bars, enhancing both the durability and economic efficiency of structures.