Abstract This paper introduces the uniformity factor μ2 for considering the local fiber distribution within elements made with Ultra-High Performance Fiber Reinforced Cementitious Composites (UHPFRC). The influence of μ2 on the strain-hardening response of UHPFRC under uniaxial tension is investigated quantitatively by means of experimental campaign and mechanical analysis. The uniaxial direct tensile test (DTT) was carried out on dumbbell specimens, extracted from a slab, to characterize the tensile behavior of UHPFRC using digital image correlation (DIC) system. Before DTT, actual fiber distribution of each specimen was measured by non-destructive test (NDT) method. Based on the present results and available literature, it is concluded that μ2 plays a significant role in tensile strain-hardening response, especially hardening strain eUtu and matrix discontinuities energy gUf, of UHPFRC. The average μ2 value for a given UHPFRC structural element is proposed to be applied for scaling the representative tensile response to intended applications.

中文翻译：

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局部纤维分布对使用 NDT 和 DIC 的应变硬化 UHPFRC 拉伸行为的影响

摘要 本文介绍了用于考虑使用超高性能纤维增强水泥基复合材料 (UHPFRC) 制成的元件内局部纤维分布的均匀性因子 μ2。通过实验活动和力学分析，定量研究了 μ2 对单轴拉伸下 UHPFRC 应变硬化响应的影响。对从板坯中提取的哑铃试样进行单轴直接拉伸试验 (DTT)，以使用数字图像相关 (DIC) 系统表征 UHPFRC 的拉伸行为。在 DTT 之前，通过无损测试 (NDT) 方法测量每个样品的实际纤维分布。根据目前的结果和现有文献，得出结论，μ2 在拉伸应变硬化响应中起着重要作用，特别是 UHPFRC 的硬化应变 eUtu 和基体不连续性能量 gUf。建议将给定 UHPFRC 结构元件的平均 μ2 值用于缩放对预期应用的代表性拉伸响应。