结构型钢纤维对单轴受压下混凝土渗透性及损伤的影响

利用改进的渗透试验装置，研究了混凝土（NC）单轴受压时结构型钢纤维（SF）掺量和荷载等级对其渗透系数的影响，并对数据进行拟合分析；同时还利用超声检测研究了不同荷载等级对SF/NC造成的损伤。分析表明:NC单轴受压时，其渗透性与荷载等级有关，且存在阈值现象，当荷载等级大于渗透阈值时，渗透系数迅速增大。结构型SF的加入可以推迟渗透阈值的出现，渗透阈值随SF掺量的提高而增大，当掺量为0、20、40、60 kg/m3时，渗透阈值分别约为0.6、0.7、0.7、0.8。试件超声波速随荷载等级变化规律与渗透系数的变化规律有一定相似性，可以用来评价NC单轴受压时的渗透性能。 

Effect of macro steel fiber on permeability and damage of concrete under uniaxial compression

Using an improved permeation test device, the effect of macro steel fiber(SF) content and load level on the permeability of concrete(NC) subjected to uniaxial compression was studied, and the data of test were fitted and analyzed. The effect of load level on damage of SF/NC was studied by ultrasonic testing. The results indicate that the permeability of NC is related to the load level, and there exists a threshold value for the applied load level. The addition of macro SF delays the threshold value, and the threshold value increases with fiber content within a certain range. When the fiber content is 0, 20, 40 and 60 kg/m3, the threshold value is about 0.6, 0.7, 0.7 and 0.8, respectively. The effect of load level on the ultrasonic pulse velocity of NC is similar to permeability coefficient, which can be used to evaluate the permeability of NC under uniaxial compression.