钢纤维形状对高性能混凝土性能的影响

试验研究了6种长径比较小且直径较粗的钢纤维(SF)(短直形、长直线形、圆弧形、闭合三角形、闭合矩形、闭合圆环形)对高性能混凝土性能的影响。通过改变SF体积分数从而改变其形成的环域个数和面积，探究二者对混凝土流动性、抗拉及抗折强度的影响，并通过研究破坏界面分析混凝土破坏形式和机制。结果表明:闭合区域个数及纤维的环域面积对混凝土流动起主要影响；闭合SF中圆环形SF对混凝土抗折及抗压强度的提升效果优于其他形状的闭合SF。短直形SF与圆环形SF混杂试验中，圆环形SF体积分数为1vol%、短直形SF体积分数为0.5vol%时，SF/混凝土抗压强度和抗折强度提升的综合效果最佳。 

Influence of steel fiber shape on the performance of high-performance concrete

The influence of six kinds of steel fibers (SF) (short straight, long straight, half ring, triangular, rectangular, circular) with small length-diameter ratio on high-performance concrete was studied. The influence of SF on the fluidity, compressive strength and bending strength of concrete was discussed by changing the volume fraction of SF to change the number and area of the ring formed. The failure mode and mechanism of concrete were analyzed by studying the failure interface. The results show that: the number of closed SF and the area of fiber ring play a major role in the flow of concrete; the circular SF in the closed SF has the best effect on the bending and compressive strength of concrete than other closed SF. In the hybrid test of short straight SF and circular SF, when the volume fraction of circular SF is 1vol% and the volume fraction of short straight SF is 0.5vol%, the improvement on the compressive strength and bending strength of SF reinforced concrete is the best.