Constitutive Behaviour of Flyash Concretes with Steel Fibres in Ordinary Grades

Abstract

Construction activity is increasing aII over the world today To minimise the construction cost and to increase the performance of structural concrete without losing its original propefiies is a big challenge before the construction industrsz To some extent this can be achieved using pozolanas and fibres in concrete production. The present paper discusses the stress'strain behaviour ofsuch llyash concrete with steel fibres in ordinary grade. M30 grade of concrete was designed using the IS mix design code 10262'1982. Cylinders were cast with conventional'concrete and Ilyash with random steel fibres. The cement was replaced by flyash up to 40% at regular intervals of 10%. The split tensile strength of conventional concrete with 1% steel fibres and steel fibred flyash concrete were evaluated. Concrete with flyash and steel showed an improvement in ductile behaviour. This paper presents a complete stress-strain behaviour of such concretes. An empirical equation has been proposed to predict the behaviour of such concrete under compression. The static moduli of elasticity of concrete at various percentage replacements ofllyash are reported. The energy absorption capacity ofsteel fibred flyash concretes was evaluated. The percentage ofsteel fibres added is kept constant at 1% and aspect ratio as 75 for al| replacements ofllyash. The normalised stress'strain curves were plotted and are reported. The proposed equation showed a good coruelation with experinental values