Shear Strength of Low Volume Steel Fiber Concrete Under Static or Repeated Loads

Abstract

Studies have shown that steel fibers improve concrete performance specially shear and tensile strength. The degree of improvement gained depends mainly on the type, shape and volume of the steel fibers. The main objective of this study is to investigate the shear behavior of low volume content steel fiber concrete under static or repeated loading. Low volume steel fibers (V f < 1 %) presents an economic solution that guaranties suitable workability for concrete. Three groups with a total number of one hundred twenty-six push-off concrete specimens were casted and tested. The experimental variables were the concrete compressive strength, the shape of the steel fibers (corrugated or hooked end steel fiber), the volume content of the steel fiber (0.15, 0.30 and 0. 45%) and the type of loading (static or repeated). The experimental test results showed up to 30% increase for the shear capacity of the concrete as well as an increase for the fatigue life due to the presence of low volume content of steel fibers. An equation is proposed to predict the fatigue life of the steel fiber concrete.