Contribution of steel fiber on the dynamic tensile properties of hybrid fiber ultra high toughness cementitious composites using Brazilian test
Contribution of steel fiber on the dynamic tensile properties of hybrid fiber ultra high toughness cementitious composites using Brazilian test
复制标题
巴西试验表明钢纤维对混合纤维超高韧性水泥基复合材料动态拉伸性能的贡献
DOI：
10.1016/j.conbuildmat.2020.118416
复制
发表时间：
2020
影响因子：
7.4
通讯作者：
Xu Shilang
中科院分区：
文献类型：
--
作者：
Zhao Xin;Li Qinghua;Xu Shilang
通过一系列准静态和动态巴西试验，研究了钢纤维（SF）对混杂纤维超高韧性水泥基复合材料（UHTCCs）动态拉伸性能的影响。在聚乙烯醇（PVA）纤维含量为2%的条件下，制备了4种不同SF含量的混杂纤维UHTCC。在准静态拉伸载荷下，含0.5% SF的复合材料表现出最高的能量耗散约为含1.5% SF的复合材料的2.9倍。而含1.5%SF的复合材料具有最高的动态拉伸强度和最大的能量耗散。SF含量的增加提高了混杂纤维UHTCC的动态拉伸强度和能量耗散，它们的贡献受应变速率的影响。基于高速图像的研究表明，随着应变速率的增加，UHTCC中的裂纹扩展速度增加，导致纤维拉伸和拔出的各种微观力学参数受到应变速率的影响。通过对比混杂纤维UHTCC和超高性能混凝土（UHPC）的动态拉伸性能，发现混杂纤维UHTCC和超高性能混凝土（UHPC）在相同冲击荷载作用下的动态能量耗散相似，但其动态抗拉强度仅为UHPC的59%~ 73%。
A series of quasi-static and dynamic Brazilian tests were conducted in this study to investigate the influence of steel fiber (SF) on the dynamic tensile behavior of hybrid fiber ultra-high toughness cementitious composites (UHTCCs). Four different kinds of hybrid fiber UHTCCs were prepared with different SF content, but the polyvinyl alcohol (PVA) fiber content remained as 2%. Under quasi-static tensile loading, the composites with 0.5% SF exhibited the highest energy dissipation approximately 2.9 times that of the composites with 1.5% SF. However, the composites with 1.5% SF was recommended to resist the dynamic tensile loading with the highest dynamic tensile strength and energy dissipation among the four composites. The increase in SF content improved the dynamic tensile strength and energy dissipation of hybrid fiber UHTCC, and their contribution was influenced by the strain rate. Based on the high speed image investigation, the crack velocity in the UHTCC increased with the strain rate, which led to the strain rate effect on the various micromechanical parameters of the fiber tension and pullout. By comparing the dynamic tensile behavior of hybrid fiber UHTCC and ultra-high performance concrete (UHPC), it was found that the dynamic energy dissipation of UHTCC were similar with that of UHPC under the same impact loading, although their dynamic tensile strength was 59%–73% of UHPC.