摘   要：通过正交试验研究单掺纳米SiO2、单掺钢纤维以及双掺纳米SiO2与钢纤维对补偿收缩混凝土抗冲击韧性的影响。根据美国ACI544委员会推荐的试验方法，采用自行设计的自由落锤冲击试验装置。研究表明，单掺钢纤维会明显增强补偿收缩混凝土的抗冲击韧性，双掺纳米SiO2和钢纤维后，抗冲击韧性增强效果更佳。与未掺纳米SiO2相比，钢纤维掺量为0.8%、1.2%、1.6%时，抗冲击能量差最大分别可提高31.9%、24.5%和33.7%，钢纤维掺量不超过1.2%时，纳米SiO2的最佳掺量是0.6%。

Abstract: Through orthogonal experiment, the impact toughness of the shrinkage compensating concrete by adding nanometer SiO2, steel fiber and adding nanometer SiO2 and steel fiber at the same time is studied. According to the United States ACI544 committee recommended test methods, the self-designed free falling hammer impact test device is used. The research results show that adding steel fiber will significantly enhance the impact toughness of shrinkage compensating concrete, double doped nanometer SiO2 and steel fiber, the enhancement effect will be better. Compared to no adding nanometer SiO2, when the steel fiber volume rate is 0.8%, 1.2% and 1.6%, the impact resistance energy difference between failure and initial crack will reach 31.9%, 24.5% and 33.7% at largest. When the steel fiber volume rate is no more than 1.2%, the optimum amount of nanometer SiO2 is 0.6%.