钢纤维对超高性能水泥基复合材料增强增韧的影响

Influence of Steel Fibers on Strengthening and Toughening of Ultra High Performance Cementitious Composites

为研究钢纤维对超高性能水泥基复合材料(UHPCC)增强增韧性能的影响,对掺加不同类型、掺量和排列方式钢纤维的UHPCC直接拉伸性能和弯曲韧性进行研究。结果表明,钢纤维明显提高UHPCC的直接拉伸性能和弯曲韧性。纤维掺量越高,增强增韧效果越明显;相同掺量下,波纹型钢纤维的增强增韧效果优于端钩型,这是由于波纹型钢纤维与基体间存在更强的机械咬合力。此外,沿拉应力方向有序排列钢纤维的方式更有利于UHPCC的增强增韧,表现为破坏过程呈现一定的应变硬化特征。

Based on the experimental results of tensile loading and bending toughness testing of ultra high performance cementitious composites （UHPCC） incorporating steel fiber of different types, dosages and arrangement, the influence of steel fibers on strengthening and toughening of UHPCC were studied. The results indicate that the addition of steel fiber can significantly improve both tensile and bending toughness properties of UHPCC. The higher the dosage of steel fiber, the better the effect of strengthening and toughening is. Notably, the effect of crimped steel fiber on strength and toughness of UHPCC is more efficient than that of hooked steel fiber, which should be caused by the more pronounced mechanical interlocking between fiber and matrix which further improve the interfacial bond in between. Moreover, the orderly arrangement of steel fiber along the direction of tensile stress provides a better performance with respect to tensile strength, fracture energy, multiple micro-cracking and strain hardening behavior. y words