This research investigated the mechanical performance of Functionally Graded Fiber-Reinforced Concrete (FG-FRC) produced via extrusion with a targeted fiber injection. Flexural toughness was assessed using a modified ASTM C1609, and fracture properties were analyzed through implementation of the two-parameter fracture model. The study introduced an innovative targeted fiber injection technique using a conveyor system, tailored for the integration of high-stiffness steel fibers into the mortar prior to extrusion. This method permits the use of fibers in more extrusion systems, since the fibers cannot jam in the pump. The research utilized digital image correlation to observe the full displacement field, allowing for an in-depth examination of crack propagation and strain localization. Additionally, X-ray computed tomography was employed to analyze fiber dosage and distribution within the FG-FRC layers. Results indicated that the targeted fiber injection method facilitated effective fiber distribution within FG-FRC layers, leading to enhanced mechanical performance through fiber dosage’s optimization.

中文翻译：

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靶向纤维注射挤压功能梯度纤维增强砂浆的力学性能


本研究调查了通过挤出和目标纤维注射生产的功能级配纤维增强混凝土 （FG-FRC） 的机械性能。使用改进的 ASTM C1609 评估弯曲韧性，并通过实施双参数断裂模型分析断裂性能。该研究引入了一种使用输送系统的创新靶向纤维注射技术，该技术专为在挤出前将高刚度钢纤维集成到砂浆中而设计。这种方法允许在更多的挤出系统中使用纤维，因为纤维不会卡在泵中。该研究利用数字图像相关来观察完整的位移场，从而可以深入研究裂纹扩展和应变定位。此外，采用 X 射线计算机断层扫描分析 FG-FRC 层内的纤维剂量和分布。结果表明，靶向纤维注射方法促进了 FG-FRC 层内的有效纤维分布，从而通过优化纤维剂量来提高机械性能。