基于磁探针电感检测法检测UHPFRC中纤维的空间分布

Detection of Spatial Distribution of Fibers in UHPFRC Based on Magnetic Probe Inductance Detection

研究了超高性能纤维混凝土(UHPFRC)中纤维不均匀分布对材料性质的影响,基于使用的钢纤维的磁感效应,无损的磁探针电感检测法可以检测超高性能混凝土构件中钢纤维的二维平面以及三维空间分布。将这种无损检测方法应用于超高性能混凝土棱柱体试样,通过放置磁性探针在棱镜的侧表面,也即抗弯测试中的顶部和底部表面来测量电感,从而得到纤维分布的定量参数。通过无损检测得到纤维分布,并由四点抗弯试验和基于截面的图像分析得到了验证。试验还表明,是否采用振动成型将影响棱柱体试样中的纤维分布。添加3%体积率钢纤维的超高性能混凝土棱柱体,在振动成型条件下,有着更高的电感数据、单位面积纤维数和更高的抗弯强度。

The influence of the un-uniform distribution of fibers in ultra-high performance fiber reinforced concreteon the properties was studied. Based on the magnetic effect of steel fiber, the non-destructive magnetic probe inductancedetection method can be applied to detect the two-dimensional plane and three-dimensional spatial distribution of steelfiber in ultra -high performance concrete. This non -destructive testing method is applied to ultra -high performanceconcrete prism samples. The measurement inductance is obtained by placing a magnetic probe on the side surface of theprism, i.e., the top and bottom surfaces of the bending test, to obtain a quantitative parameter for the fiber distribution. Thefiber distribution obtained by non-destructive testing was verified by the four-point bending test and cross-sectional imageanalysis of the specimen. The results also show that the use of vibration shaping would affect the fiber distribution of theprismatic sample. Addition of 3% volume rate of steel fiber ultra -high performance concrete prism, in the vibrationmolding conditions, have a higher inductance data, the number of fibers per unit area and higher bending strength.