摘   要：对普通混凝土（NC）、再生混凝土（RAC）、钢纤维混凝土（SFRC）和钢纤维再生混凝土（SFRRAC）的弯曲疲劳性能进行了试验研究。分析了应力水平、再生骨料和钢纤维对混凝土弯曲疲劳寿命和离散性的影响规律。在试验研究的基础上，应用疲劳寿命统计学理论拟合了各组混凝土材料弯曲疲劳寿命的两参数威布尔分布,并建立了相应的单对数和双对数弯曲疲劳方程。结果表明，再生混凝土的疲劳寿命明显低于天然骨料混凝土，离散性也更大；钢纤维可以显著提高混凝土的疲劳寿命，并降低离散性。各组混凝土材料的弯曲疲劳寿命很好地服从两参数的威布尔分布；建立的单对数和双对数弯曲疲劳方程与试验实测数据吻合良好。

Abstract: The experimental research on the flexural fatigue properties of normal concrete (NC), recycled aggregate concrete (RAC), steel fiber reinforced concrete (SFRC) and steel fiber reinforced recycled aggregate concrete (SFRRAC) is carried out. The influence rules of stress level, recycled aggregate and steel fiber on fatigue life and discreteness are analyzed. Based on the experimental studies, two-parameter Weibull distribution of flexural fatigue life of concrete is derived by using statistics theory, and the corresponding single logarithmic and double logarithmic equations are gained. The experiment results show that flexural fatigue life of recycled aggregate concrete is obviously lower than that of natural aggregate concrete, and the discreteness is greater; steel fiber can significantly improve the flexural fatigue life of concrete and decrease the discreteness. The flexural fatigue life of concrete materials follows two-parameter Weibull distribution; experimental single logarithmic and double logarithmic equations can describe the experimental test data well.