Pull-Out Behaviour of Steel Fiber in Ultra-High Performance Fiber Reinforced Concrete.

Based on the self-developed steel fiber position device that can accurately control the spatial position of steel fiber, the effects of steel fiber embedded depth, diameter and embedded angle on the pull-out behavior of steel fiber in ultra-high performance fiber reinforced concrete (UHPFRC) were studied. The results indicate that the maximum pull-out force, pull-out work, maximum pull-out stress and strength utilization rate of steel fiber increase with the increase of steel fiber embedded depth. However, the maximum average bond strength decreases with the increase of steel fiber embedded depth. With the increase of steel fiber diameter, the maximum pull-out force, pull-out work and maximum average bond strength of steel fiber increase correspondingly, while the strength utilization rate and maximum pull-out stress of steel fiber decrease. With the increase of steel fiber embedded angle, the maximum pull-out force and pull-out work of steel fiber increase first and then decrease. The maximum pull-out force and pull-out work reach the maximum value at 45° and 30° of embedded angle, respectively. When the embedded angle is 75°, the failure mode of specimen is that the steel fiber is broken. [ABSTRACT FROM AUTHOR]