Variability of concrete properties has strong influences on design and conformity assessment. However, variability of residual flexural strengths of steel fiber-reinforced concrete (SFRC) has yet been statistically investigated. In this study, a large number of SFRC specimens was sampled from a central mix concrete plant manufacturing precast SFRC elements for a real civil infrastructure project. Variability of residual flexural strengths of SFRC are reported. Results show that the residual flexural strengths of SFRC follow the log-normal distribution at large crack month opening displacement (CMOD). The origin that leads to the log-normal distribution of the residual flexural strengths of SFRC is discussed. The use of an assumed normal distribution of the residual flexural strengths of SFRC in the current design approach and conformity assessment results in more than 30% overdesign and more stringent acceptance criteria. This leads to higher materials cost and higher producer's risk, which discourage the wider adoption and application of SFRC. The logarithmic transformation provides a practical and convenient approach to design and to check the conformity of log-normally distributed SFRC properties adopting existing criteria. Compared to the typical lab-based study with limited number of specimens and test results from a well-controlled environment for material processing and specimen preparation, the field study reflects more closely the true material variability in real construction. Thus, the statistical analysis obtained and conclusions drawn from the current work are more representative.

混凝土性能的可变性对设计和合格评定有很大影响。然而，钢纤维混凝土 (SFRC) 的残余弯曲强度的可变性尚未进行统计研究。在这项研究中，大量 SFRC 试样是从一个中央混合混凝土厂为一个真正的民用基础设施项目制造预制 SFRC 元件的样本。报告了 SFRC 残余弯曲强度的变化。结果表明，在大裂纹月张开位移（CMOD）下，SFRC 的残余弯曲强度服从对数正态分布。讨论了导致 SFRC 残余弯曲强度的对数正态分布的起源。在当前的设计方法和合格评定中使用 SFRC 残余抗弯强度的假设正态分布导致超过 30% 的过度设计和更严格的验收标准。这导致更高的材料成本和更高的生产商风险，从而阻碍了 SFRC 的更广泛采用和应用。对数变换提供了一种实用且方便的方法来设计和检查采用现有标准的对数正态分布 SFRC 特性的一致性。与典型的实验室研究相比，样本数量有限，测试结果来自材料加工和样本制备的良好控制环境，现场研究更密切地反映了真实建筑中的真实材料变化。因此，