Evaluation of Mechanical Performance of High Performance Hybrid Fiber Reinforced Concrete Containing Micro Silica

Abstract

In the extended use of concrete in military applications, runway pavements and infrastructures, concrete is subjected to heavy impact loads that vary both in velocity and intensity. The addition of fibers in high performance concrete (HPC) can overcome its shortcomings such as brittleness, high shrinkage and less resistance to impact and also improve the ductile behavior and energy absorption capacity. In this study, development on strengthening of HPC using steel and Polypropylene fibers was focused. Moreover, an inclusion of volume fractions of both steel and polypropylene fibers, leads to an increase in the mechanical properties of concrete matrix. The present study represents the adding steel and Polypropylene fibres at 0.5, 1.0, 1.5, and 0.25, 0.5, 1% by volume of concrete, respectively. A concrete mix has been designed to achieve the M60 grade concrete, mixes proportioned for FRC to determine the compressive strength, split tensile strength and flexural strength of high performance hybrid fiber reinforced concrete at 28 days. The experimental results showed that the use of hybrid fibers with 1.5% steel and 1% Polypropylene fiber in HPC concrete has improved the strength of the concrete by 36% and 25.1% HPC with single fibers. The statistical tool was formulated to predict the strength properties of fiber reinforced concrete (i.e., compressive, flexural and split tensile strengths). The response surface method (RSM) was used to analyze the data and develop a regression equation. RSM was able to predict the experimentally tested values within an acceptable range.