Experimental investigation on strength and behaviour of fibre reinforced psc beams with high reactive metakaolin and silica fume

Abstract

Cement is been widely used in concrete, where the addition of mineral admixtures, like Metakaolin, Silica fume, GGBS, etc., replacing the cement has been widely accepting in newlinethe construction industry. Not only it increases the properties of the concrete but also plays a vital role in the environmental aspects.Even though concrete is most commonly used construction industry, it has certain newlinedisadvantages such as low tension and ductility characteristics. This low tensile strength and ductilty of concrete can be improved by the use of variety of fibres in the concrete.Prestressing is a novel technique which provides economical and elegant structural newlinesolutions for a wide range of applications especially for long span bridges and fly overs. In Post tensioned members, the tensioned steel withstands stresses several times greater than that carried by the reinforcing bars. They have strength several times greater than normal reinforced members. Use of fibres in concrete helps in controlling plastic and drying shrinkage cracks effectively, also lessen the crack widths and enhances ductility characteristics. This experimental study involves finding out of optimum volume fraction of fibres for M-60 grade concrete. Casting and testing of post tensioned beams, incorporated with sisal, polypropylene and steel fibres, at optimum volume of fibres under two point loading experimental set up. This work involves finding out the deflection, ultimate load carrying capacity and crack pattern of post tensioned beams, which are reinforced with three different newlinekinds of fibres. Comparison of strength and behaviour of concrete in between these fibres are made.The use of mineral admixtures in the concrete, it lowers the permeability, and thus reduces the bleeding of water. Some of the fibre type builds higher resistance to abrasion, shatter and impact.Thusincreases