超细钢纤维混凝土弯曲韧性研究

Research on Flexural Toughness of Extra-fine Steel Fiber Concrete

为研究钢纤维混凝土的弯曲韧性,按照CECS 13:2009对不同纤维体积掺量(Vf=0、1%、2%、3%)、不同纤维长度(Lf=13mm、6mm)的钢纤维混凝土梁进行了四点弯曲试验。结果表明,掺加钢纤维对混凝土的抗压强度影响很小;随着纤维掺量的增加,SFRC梁的承载力提高、韧性增强、荷载-挠度曲线也更饱满,特别是当纤维长度为13mm时;根据荷载-挠度曲线提出了一种确定初裂点的方法 ,结果表明该方法可以有效判定初裂点的位置。

In order to study the flexural toughness of steel fiber reinforced concrete （SFRC）, the four-point bending test of SFRC was carried out with different fiber volume contents （Vt=0,1,2 and 3%） and different fiber lengths （Li=13 and 6mm） according to CECS 13：2009. The results showed that, adding fibers provides a negligible change on the compressive strength. The load carrying capacity and flexural toughness increased with the increase of fiber content, the load-deflection curves become more full, especially when Lf=13mm. According to the load-deflection curves, an effective method which can identify the first-peak load was proposed, this method can be used to identify the position of the initial crack point.