Relationship between Fiber Orientation and Flexural Strength in Ultra-High-Performance Fiber-Reinforced Concrete Panels

Abstract

In this study, the influence of fiber orientation on the flexural strength of ultra-high-performance fiber-reinforced concrete (UHPFRC) was examined. To this end, a circular UHPFRC panel measuring φ1,200 × 50 mm was cast from its center, and test specimens measuring 50 × 50 × 200 mm with 10 mm notches for three-point bending tests were cut from it with angles of 0, 30, 60 and 90° between the specimen axis and the radial direction of the panel. After the bending test, fiber orientation on the ruptured surfaces of the specimens was observed. The flexural strengths of the specimens cut at angles of 60, 30 and 0° were 80, 40 and 10% of that for the specimen cut at an angle of 90°. It was also found that the flexural strength of specimens cut from a rectangular panel cast from its center point depended on their original positions and orientation within the panel. Similar fiber orientation characteristics were found in the circular and rectangular panels.