STEEL FIBRE REINFORCED CONCRETE

STEEL FIBRE REINFORCED CONCRETE

J.Thomas Britto

Dept of civil engineering

Thomasbritto3@gmail.com

 P.R.engineering college, Thanjavur

ABSTRACT

SFRC is a concrete that has a homogenous distribution of randomly oriented discontinuous and discrete steel fibres. Steel fibres are introduced in the concrete matrix during the mixing of its constituent ingredients. Upon hardening, these fibres improve the properties of concrete such as ductility, fracture toughness, energy dissipation, impact resistance, fatigue resistance and limiting of crack propagation. Under tension, as cracks start propagating inside concrete, steel fibres present in the matrix bridge the cracks and transfer the tension across them during this process. SFRC actually causes no considerable increase in the flexural strength but improves the load carrying capacity of the structural member on account of increased toughness and rotation capacity. The use of SFRC in grade slabs such as industrial floors, warehouses, ports and highway pavements have been prevalent in many countries for over 40 years. It is observed that for a plain concrete, a sudden and brittle mode of failure occur after the peak load is reached. But when a sufficient ductility is ensured in the beam with the addition of steel fibres in concrete, a strain softening phenomenon is observed after the peak load. Thus, with this kind of toughening behavior in the beam, post-crack flexural strength of SFRC is guaranteed. The applications of SFRC are  Fibres working in ULS, SLS, Grade slabs, Shortcrete tunnel linings, Segmental linings, Structural elements, Liquid tight floors, Water tight raft foundations. There are varieties of fibre available in the markets but they must be selected based on the requirements of the user and the applications they will be put to use. This paper therefore studies the mechanic properties, technologies, and applications of SFRC.

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