单向分布钢纤维增强水泥基复合材料(I):钢纤维方向控制

Aligned Steel Fibre Reinforced Cement Based Composites(I):Orientation Control of Steel Fibres

对恒定匀强磁场作用下钢纤维增强水泥净浆中钢纤维的受力状况及转动运动状态进行了分析,确定了钢纤维转动角加速度与磁场磁感应强度及磁场作用时间之间的关系,并据此计算了钢纤维达到设计方向所需的磁场磁感应强度及磁场作用时间,从而确定了单向分布钢纤维增强水泥净浆的制备条件.根据理论计算结果,在磁场磁感应强度为1.13×10-5 T、磁场作用时间为60s条件下制备了单向分布钢纤维增强水泥净浆试件,测试了试件中钢纤维的方向分布,结果表明,试件中80%左右的钢纤维方向与设计方向基本一致,钢纤维方向系数达到0.968.

The force state and the rotational motion of single steel fibre in cement paste subjected to magnetic force caused by external uniform magnetic field were analysed. The relationship among the rotating accelerated angular velocity of steel fibre and the magnetic induction, working time of magnetic field was obtained. Based on this relationship, the magnetic induction and working time of magnetic field were caicuiated according to the designed orientation of steel fibre, and the preparation conditions for aligned steel fibre reinforced cement paste was confirmed. Based on the theoretical calculation result, an aligned steel fibre reinforced cement paste speci- men was prepared using external uniform magnetic field with magnetic induction 1.13 × 10^-5 T for 60 s, the orientation distribution of steel fibres in cement paste specimen was tested. The test results show that for nearly 80% of steel fibres in the cement paste specimen, their orientations are in close agreement with designed orientation, and the orientation factor of steel fibres reaches 0.968.