AN EXPERIMENTAL STUDY OF THE STRENGTH OF PLAIN CONCRETE WITH TWISTED STEEL COUPLETS AS FIBRE REINFORCEMENT

From amongst the large family of fibres which have been used to improve the structural properties of concrete such as tensile strength, shear strength, torsional strength or response against random dynamic forces couplets of steel wires twisted together have been selected as fibre reinforcement for the experimental study details of which are presented in this paper. The couplets were 2" (50mm ) long. The purpose of twisting the wires together was to improve the bond in order to avoid premature failure which might be caused due to slipping. The ratio of the fibre reinforcement ranged between 0.0% to 2.0% by weight with an increment of 0.25%. Nine batches of concrete were prepared and from each, 15 specimens were cast and fibres were randomly added while the concrete ingredients were being mixed in the pan-mixer. Thus altogether 135 specimens were tested. The study was conducted in terms of compressive strength, tensile strength, modulus of elasticity and Poisson's ratio. The results are encouraging and marked improvement in almost all the properties of concrete has been achieved