Effects of Longitudinal Reinforcement Ratio on Flexural Capacity of One-Way Slab of UHPC Waffle Bridge Deck

To study the effect of longitudinal reinforcement ratio on the flexural capacity of a one-way slab of an ultra-high performance concrete (UHPC) wafer bridge deck, six full-scale T-beam models with varying longitudinal reinforcement ratios were produced by using the principle of equivalent width to simplify the analysis. Firstly, the basic mechanical properties of UHPC were studied, followed by the flexural behavior and failure mode of T-shaped UHPC beams through loading experiments. Secondly, a constitutive model for the tensile and compressive strength of UHPC was proposed based on the results of material performance tests. Through section analysis, a formula for calculating the ultimate flexural capacity of T-shaped UHPC beams was derived. Finally, the applicability of the proposed formula was validated based on previous research results. The research findings indicate that although reducing the longitudinal reinforcement ratio will weaken the ultimate flexural capacity and ductility of T-shaped UHPC beams, the failure mode of the components will not change, and T-shaped UHPC beams will still exhibit ductile failure characteristics, even with low or no reinforcement, due to the excellent tensile strength and toughness of UHPC. Moreover, the results of section analysis derivation indicate that the coefficient of variation of the ultimate tensile strength of UHPC under tension is proportional to the longitudinal reinforcement ratio. Therefore, increasing the longitudinal reinforcement ratio can significantly enhance the tensile strength of UHPC. The proposed formula was found to be applicable. © 2023 Science Press. All rights reserved.