Mechanical properties of hybrid polypropylene-steel fibre-reinforced concrete composite

Abstract

Abstract Fibres are materials with axial resistance to load that can withstand tensile stresses also when they are mixed in concrete. Recent research shows that the use of fibres improves the mechanical properties in terms of tensile strength and use of hybrid fibres, the mechanical properties further get improved. This paper presents an experimental investigation to quantify the improved Mechanical Properties for different amounts of mono fibres as hook end steel fibres and hybrid fibres that is a combination of hook end steel and polypropylene fibres. Compressive and splitting tensile strengths, modulus of rupture, and modulus of elasticity are studied. Steel fibres are used in the volume fractions of 0%, 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1%, 1.25% and polypropylene fibres in a fixed quantity of 400 gm/m 3 in M35 grade concrete. From the results, all the Mechanical properties improve with an increase in the fibre content up to an optimum volume fraction of 0.9%. Addition of steel fibres and polypropylene fibres improves flexural strength and split tensile strengths significantly. However, compressive strength and elastic modulus are slightly improved. It is also observed that the addition of fibres increases the post-peak behaviour of the concrete.