钢纤维取向角对超高性能混凝土抗拉强度的影响

为了明确钢纤维在超高性能混凝土(UHPC)中的增韧效果,人为改变钢纤维在UHPC拌合物中的排列取向。采用随机浇筑、顺拉伸方向浇筑、垂直拉伸方向浇筑三种成型模式成型了UHPC拉伸试件,通过轴拉试验得到UHPC的应力-应变曲线,并从断面观测钢纤维的分布取向。试验结果表明,钢纤维的取向对拉伸强度有决定性影响,其中,顺拉伸方向浇筑的UHPC抗拉强度达到12.4 MPa,极限应变达到了0.003 8;从拉伸断面上分析得出UHPC的抗拉强度与钢纤维沿轴向取向角有线性相关性。

The Effects of Steel Fiber Orientation on Tensile Strength of Ultra-high Performance Concrete

In order to clarify the toughening effect of steel fiber in ultra-high performance concrete(UHPC),the orientation of steel fiber in UHPC mixture was changed artificially by changing the pouring direction of UHPC.The tensile test on shape specimens was formed by three kinds of molding models:random pouring,in direction of stretching and vertical direction.The stress-strain curve of UHPC was obtained by axial tensile test,and the distribution orientation of steel fiber was observed from the cross section.The test results show that the orientation of steel fiber has a decisive influence on the tensile strength.Especially,the tensile strength of UHPC is up to 12.4 MPa along the direction of pouring,and the ultimate strain reaches 0.003 8.From the analysis of the tensile section,it is concluded that the tensile strength of UHPC is linearly related to the orientation angle of the steel fiber.