Fresh and hardened properties of steel fiber reinforced concrete produced with fibers of different lengths and diameters

Abstract

Concrete is a brittle material which has a low tensile strength and a low tensile strain capacity. These weak points of concrete can be resolved by including fibers made of different materials with high technical specifications. This special type of concrete is known as Steel Fiber Reinforced Concrete (SFRC) and exhibits superior properties in terms of ductility, fracture energy, toughness, strength and durability due to the addition of steel fibers when compared to conventional concrete. SFRC has a varied application area. In practice, steel fibers which have different lengths, diameters, and aspect ratios are used. These variable characteristics of steel fibers have highly influence on the performance of SFRC. The goal of this study is aimed at creating a standard foresight in determining the fiber types by comparing the steel fiber types which have the same tensile strengths and different lengths, diameters, and aspect ratios. For this purpose, the series of SFRC specimens which have the same concrete mixing ratios were produced by using steel fibers which have the same tensile strengths and different lengths, diameters, and aspect ratios. The fresh properties of the produced SFRC specimens were determined by the Slump test. The hardened properties were determined by compressive and flexural strength tests. It was shown that the fresh and hardened properties of the SFRC specimens were changed by steel fibers that had the same shapes, tensile strengths and different lengths, diameters, and aspect ratios. The optimum steel fiber types were determined according to the targeted fresh and hardened properties of SFRC.