为研究配筋率对钢/聚丙烯（PP）混杂纤维增强超高性能混凝土（UHPC）梁受弯性能的影响规律，设计不同配筋率（0.28%~1.27%）的钢/PP混杂纤维增强UHPC梁进行受弯性能试验，分析试件的荷载-位移曲线、裂缝发展模式、荷载-钢筋应变曲线、跨中截面应变分布及极限承载力等关键性能指标，并与同等截面设计的C50普通钢筋混凝土梁进行对比。结果表明： 1）在同等截面条件下，相较于C50混凝土梁，钢/PP混杂纤维增强UHPC梁的初裂荷载、屈服荷载、峰值荷载和极限荷载分别提高6.67%、16.00%、25.00%和36.30%，抗弯刚度提升56.4%，延性系数提高26.2%，平均裂缝间距减小28.5%。2）配筋率是影响钢/PP混杂纤维增强UHPC梁性能的主要因素，当配筋率从0.28%增至1.27%时，屈服荷载、峰值荷载和极限荷载分别提升128.3%、128.8%和177.1%，抗弯刚度提高67.6%，平均裂缝间距减小28.5%。研究证实，纤维对受拉区抗力的贡献不可忽略。根据试验结果反算，建议受拉区等效系数取值为0.40，该取值下的承载力计算值与试验值吻合良好。

Steel/polypropylene (PP) hybrid fibers can enhance the high-temperature resistance and corrosion durability of ultra-high performance concrete (UHPC) structures, but simultaneously affect their structural mechanical performance. To investigate the influence of reinforcement ratio on the flexural behavior of steel/PP hybrid fiber-reinforced UHPC beams and quantify the improvement in mechanical properties, the authors design a series of such beams with different reinforcement ratios (0.28% to 1.27%) for flexural tests, comparing them with normal C50 reinforced concrete beams of identical cross-section. Key performance indicators including load-displacement curves, crack development patterns, load-steel strain curves, strain profile at mid-span, and ultimate load-carrying capacity are observed. The results indicate that: (1) Under the same cross-sectional conditions, compared to C50 concrete beams, the steel/PP hybrid fiber-reinforced UHPC beams exhibit increases of 6.67%, 16.00%, 25.00%, and 36.30% in cracking load, yield load, peak load, and ultimate load, respectively. Flexural stiffness increases by 56.4%, the ductility coefficient improves by 26.2%, and the average crack spacing reduces by 28.5%. (2) Reinforcement ratio is identified as a primary influencing factor. As the reinforcement ratio increases from 0.28% to 1.27%, the yield load, peak load, and ultimate load increase dramatically by 128.3%, 128.8%, and 177.1%, respectively, flexural stiffness improves by 67.6%, and average crack spacing decreases by 28.5%. The results confirm that the contribution of fibers to the tensile resistance cannot be neglected. Based on back-calculation from experimental data, a recommended equivalent coefficient of 0.40 for the tensile zone is proposed. Calculations using this value show good agreement with test results.