Influence of amount and aspect ratio on direct shear behavior of fiber reinforced concrete

ABSTRACT: It is generally believed that one of the most important steps in the design of concrete members is the shear design. The main objective of this study is to analyze the shear behavior of two different types of fiber reinforced concrete. This experiment of reinforcement has been carried out with different amounts of steel fibers and aspect ratios. The current study therefore will conduct an experiment on a comparison between steel fibers reinforced concrete and plain concrete. The materials used in the concrete mix are blast furnace slag cement (BFSC), crushed limestone coarse and fine aggregates from Beparmak Mountains. Other materials include hooked-end steel fibers, super-plasticizing admixture, and drinkable water. Water to cement ratio for normal strength concrete is 0.50 and for high strength is 0.43. In the shear test the strength of reinforced concrete went up by increasing the volume fraction of fiber. Increasing volume from 0 to 1.5% increased 122.7% shear strength for C30, l/d 65. Similar results were obtained for C30, with l/d 80. Volume fractions of steel fibers ranging from 0 to 0.5 %, shear strength increased 35 % and from 0 to 1%, 78.7% increase in shear strength were obtained. In high strength concrete C50 the shear strength was affected by adding volume fraction of fibers. The results show that applied shear strength increased 151.4% for 1.5% amount of steel fiber and also 66% for 0.5% amount and 114% increased for 1% volume fraction of steel fibers. Results have shown that aspect ratio has no clear effect on shear strength. Because there is not much different between results of concrete with l/d 65 and concrete with l/d 80. Keywords: Shear strength, Steel fiber, Concrete class, Fiber reinforced concrete. …………………………………………………………………………………………………………………………