Mechanical properties of high-strength concrete containing silica fume and various steel fiber contents

Abstract

This study mainly focused on investigating the mechanical properties of high-strength concrete (HSC) using 8% silica fume (SF) as a Portland cement replacement combining with low steel fiber contents to explore the effectiveness of using low steel fiber contents in improving the mechanical properties of HSC using SF. Three HSC mixture proportions were designed with a water/binder ratio of 0.32 and steel fiber additions to the concrete mixture of 0%, 0.4%, and 0.6% by volume of concrete. The mechanical properties of HSC investigated in this study included compressive strength, elastic modulus, Poisson's ratio, and splitting tensile strength. The experimental results showed that the use of low steel fiber contents improved the mechanical properties of HSC using SF, specifically: compressive strength higher by 2.83 – 8.82%, elastic modulus higher by 6.18 – 8.68%, Poisson's ratio lower by 27.41 – 30.46%, and splitting tensile strength higher by 29.47 – 46.40% than that of HSC without steel fiber. The positive correlation between compressive strength and splitting tensile strength and the negative correlation between elastic modulus and Poisson's ratio of concretes were also established. In summary, the use of steel fibers at 0.6% by volume was effective in improving the mechanical properties of HSC using SF.