Abstract The long-term behavior of cracked fiber reinforced concrete is still poorly understood, and the interaction between fibers and matrix is of high importance. This paper presents the results of a numerical investigation into the creep of two types of polypropylene fiber reinforced concrete under sustained uniaxial tensile loading with discrete fiber modeling. The material models are calibrated on an extensive experimental program, comprising both short-term and creep tests. The influence of the fiber dispersion is statistically assessed in a Monte-Carlo analysis. The numerical results are compared against the experimental data. The results predict no structural failure after 50 years under load. The creep of the considered FRC is mainly an SLS problem, rather than a ULS issue. The two-phased modeling approach predicts low fiber load ratios, amounting to only 10% of the tensile strength, but bending moments at the crack planes greatly increase the local stresses. The fiber stress is mainly determined by the embedded angle of the fiber, rather than the embedded length or the fiber’s proximity to other fibers. Finally, it is shown that increasing the number of fibers decreases the final creep crack width, with diminishing effects at higher number of fibers crossing the crack.

中文翻译：

---

聚合物纤维增强混凝土的蠕变：离散纤维处理的数值模型

摘要 开裂纤维增强混凝土的长期行为仍知之甚少，纤维与基体之间的相互作用非常重要。本文介绍了使用离散纤维建模对两种类型的聚丙烯纤维混凝土在持续单轴拉伸载荷下的蠕变进行数值研究的结果。材料模型根据广泛的实验程序进行校准，包括短期和蠕变测试。光纤色散的影响在蒙特卡罗分析中进行统计评估。将数值结果与实验数据进行比较。结果预测在负载下 50 年后不会发生结构故障。所考虑的 FRC 的蠕变主要是 SLS 问题，而不是 ULS 问题。两阶段建模方法预测低纤维负载率，仅占抗拉强度的 10%，但裂纹平面处的弯矩大大增加了局部应力。纤维应力主要由纤维的嵌入角度决定，而不是由嵌入长度或纤维与其他纤维的接近程度决定。最后，结果表明，增加纤维数量会降低最终蠕变裂纹宽度，而越过裂纹的纤维数量越多，效果越小。