Effect of Steel Fibers on Shear Behavior of Prestressed Concrete Beams

Abstract

Four full-scale prestressed concrete (PC) I-beams were tested to study the effects of steel fibers on the increase in shear strength and ductility of beams. Beams were cast with no traditional transverse steel reinforcement. To study the effect of steel fibers on shear behavior, all four beams were cast using different amounts of steel fibers. The beams were subjected to concentrated vertical loads up to their maximum shear or moment capacity using four MTS actuators in load and displacement control mode. During the load tests, Linear Voltage Displacement Transducers (LVDTs) were used to measure displacements at several critical points on the web in the end zone of the beams. Several LVDTs were also placed under the beams at the points of loading to measure the actual total and net displacements of the beams. From the load tests, it was observed that the shear capacities of the beams increased significantly due to the addition of steel fibers in concrete. Complete replacement of shear reinforcement with steel fibers also increased the ductility and energy dissipation capacity of the PC I-beams.