【摘要】 为提升常规钢纤维超高性能混凝土（UHPC）湿接缝的经济性，采用玄武岩纤维部分替代钢纤维，形成混杂纤维UHPC材料。通过材料性能试验，明确玄武岩纤维对UHPC基本力学性能和流动性的影响规律，确定玄武岩纤维的最优掺量。然后对最优掺量下混杂纤维UHPC的力学性能、自由收缩和界面黏接强度等接缝材料关键性能指标进行测试。结果表明：玄武岩纤维的加入会降低混凝土流动性，对UHPC抗压性能和弹性模量影响较小，但对轴拉初裂强度具有增强作用；玄武岩纤维体积掺量0.5%为混杂纤维UHPC湿接缝材料兼顾性能和经济的最优掺量，该掺量下混杂纤维UHPC的轴拉初裂应力能够达到7.5 MPa，自然养护条件下140 d内自由收缩最大值为213με，界面黏接性能和2%钢纤维掺量UHPC接近，优于普通混凝土界面黏接性能，对比2%钢纤维掺量UHPC，成本能够降低1 014元/m~3。更多还原

【Abstract】 To save the cost of conventional steel fiber reinforced ultra-high performance concrete(UHPC)wet joints,basalt fiber is used to partially replace steel fiber to form hybrid fiber reinforced UHPC.Through the material property test,the impact of basalt fiber on the mechanical properties and fluidity of hybrid fiber reinforced UHPC was investigated,and the optimal volume fraction of basalt fiber was addressed.Subsequently,some key parameters of joint materials such as mechanical properties,free shrinkage,and interfacial bonding strength of hybrid fiber reinforced UHPC under the optimal dosage of basalt fiber were tested.The results show that the addition of basalt fiber can reduce the fluidity of concrete and has minor impact on the compressive properties and Young′s modulus of UHPC,while it can enhance the axial tensile initial crack strength.Considering the mechanical property and economy,the optimal volume fraction of basalt fiber is 0.5%.With this volume fraction,the axial tensile initial crack stress of hybrid fiber reinforced UHPC can reach 7.5 MPa,and the maximum autogenous shrinkage within 140 days under natural curing is 213 με.The interface bonding performance of 0.5% basalt fiber modified UHPC is like that of the conventional UHPC with a steel fiber volume fraction of 2% and is better than that of ordinary concrete interface bonding performance.Compared with 2% steel fiber reinforced UHPC,the cost can be reduced by 1 014 yuan/m~3.更多还原