Effect of steel fiber-volume fraction and distribution on flexural behavior of Ultra-high performance fiber reinforced concrete by digital image correlation technique
Effect of steel fiber-volume fraction and distribution on flexural behavior of Ultra-high performance fiber reinforced concrete by digital image correlation technique
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DOI：
10.1016/j.conbuildmat.2021.126281
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发表时间：
2022-01-05
影响因子：
7.4
通讯作者：
Fu, Jiyang
中科院分区：
文献类型：
--
作者：
Meng, Shaoqiang;Jiao, Chujie;Fu, Jiyang
研究了钢纤维体积分数（0.5%、1.0%、1.5%和2.0%）及其分布对超高性能纤维混凝土（UHPFRC）抗弯性能的影响。采用数字图像相关（DIC）技术对UHPFRC在弯曲载荷作用下的裂纹扩展行为进行了分析。随着纤维体积分数的增加，裂纹扩展路径变得更加曲折。基于UHPFRC的弯曲响应和裂纹面上纤维分布，讨论了纤维分布特性与抗弯性能的关系。S0.5、S1.0、S1.5、S2.0的单位面积纤维数分别为7根、14根、21根、31根。不同纤维体积分数下，裂纹区纤维拉拔长度约为3.56 mm。S0.5、S1.0、S1.5和S2.0的纤维取向因子（eta(theta)）分别为0.80、0.79、0.69和0.61。提出了光纤拉出数与eta（θ）之间的二次关系。UHPFRC的弯拉强度比（beta）约为2.52，表现出挠曲硬化行为。最后，基于基体软化模型和纤维桥接曲线模型，采用逆分析方法对UHPFRC的开裂后拉伸行为进行了分析。三线性软化曲线分析得到的拉伸软化曲线与实验结果吻合较好。
This paper investigated the effect of steel fiber-volume fraction (0.5%, 1.0%, 1.5%, and 2.0%) and distribution on the flexural behavior of ultra-high performance fiber reinforced concrete (UHPFRC). Digital image correlation (DIC) was used to obtain the crack propagation behavior of UHPFRC under bending load. With increasing fiber-volume fraction, the crack-propagation path becomes more zigzagged. Based on the flexural response of UHPFRC and fiber distribution on the crack plane, a correlation between fiber distribution characteristics and flexural behavior was discussed. The fibers number per unit area for S0.5, S1.0, S1.5, and S2.0 were 7, 14, 21, and 31, respectively. The fiber pull-out length in cracked zone with different fiber-volume fractions was about 3.56 mm. The fiber orientation factor (eta(theta)) of S0.5, S1.0, S1.5, and S2.0 were 0.80, 0.79, 0.69 and 0.61 respectively. A quadratic relationship between the eta(theta) and the fiber pull-out number is proposed. The flexural-tensile strength ratio (beta) is about 2.52 for UHPFRC exhibiting deflection hardening behavior. Finally, the post-cracking tensile behavior of UHPFRC was analyzed based on the matrix softening and fiber bridging curve models by the inverse analysis method. The tension softening curves obtained from the tri-linear softening curve analysis exhibited good agreement with the experimental results.