Mechanical performance of extruded functionally graded fiber-reinforced mortar with targeted fiber injection

This research investigated the mechanical performance of Functionally Graded Fiber-Reinforced Concrete (FGFRC) 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.