Mechanical properties and constitutive stress-strain behaviour of steel fiber reinforced concrete under uni-axial stresses

摘要

This paper presents the mechanical properties and stress-strain behaviour of low and high strength concrete (30 and 70 MPa) reinforced with hooked-end steel fibers. In this investigation various strength properties of SFRC are studied such as compressive strength, direct tensile strength, flexural strength and stress-strain behaviour of concrete under uni-axial stresses. Hooked-end steel fibers of 25 mm length and aspect ratio of 62.5 used at different fiber volume fractions varied from 0.0, 0.5, 0.75, 1 and 1.25%. The optimum dosage of steel fiber achieved at 1% fiber volume fraction. Experimental results shows that there is no significant improvement in compressive strength with addition of steel fibers. Unlike the concrete in compression percentage strength improvement in direct tensile strength and flexural strength is more. Addition of hooked-end fibers significantly influenced the stress-strain behaviour of concrete under uni-axial stresses. Non-linear regression analysis of test data for various strength properties are also conducted and obtained results are in good agreement with the test results. The enhancement in strength with the addition of fibers is mainly due to fibers in concrete delay the formation of cracks.