A study for effect of steel fibre on strength of conventional concrete

Abstract

Discrete discontinuous fibre reinforced concrete (FRC) is a composite material made up of Portland cement, aggregate, and discrete discontinuous fibres used to construct bridges and other structural components. Why would we want to put such fibres in concrete in the first place, anyway? Plain, unreinforced concrete is discouraged because it is a fragile, low-tensile-strength, low-strain-capacity material that should be avoided if possible. A random distribution of discontinuous fibres was intended to bridge over fractures as they expanded, restoring the material's “ductility” after the cracks had developed. Fibre reinforced concrete (FRC) can endure considerable pressures with a reasonably high strain capacity at the post-cracking stage due to the strength and connection of the fibres to the concrete, provided the fibres are sufficiently strong and well-bonded to the concrete. There are, however, other (and more cost-effective) ways to increase the strength of concrete than the ones listed above. The fibres' most significant contribution is to enhance the toughness of the concrete, regardless of the kind of force applied to it. As a consequence, although the fibres have a tendency to increase strain at peak load, they also absorb a significant amount of energy throughout operation in the post-peak section of the load vs. deflection curve. Fiber reinforcement in the form of short, discrete fibres functions as stiff inclusions in the concrete matrix and is a very efficient means of reinforcing concrete. In terms of particle size and number, they are comparable to aggregate inclusions. It is believed that conventionally reinforced structural elements will be more resistant to cracking, deflection, and other issues that impact serviceability.