INVESTIGATIONS ON STRENGTH OF FLY-ASH HIGH STRENGTH CONCRETE

Abstract

The use of flyash in structural concrete is an attractive proposition for technoeconomic reasons. The present day methods for analysis and design of concrete structures and the adoption of limit state concept require accurate quantitative estimate of several structural properties of the material. The effect of flyash on various properties of the high strength concrete has been the subject of considerable research but there are few reports on the effect of flyash on various properties of high grade concretes. This dissertation is an experimental and theoretical investigation on the effect of various dosages of tlyash (0%, 5%, 10%, 15% and 20% by weight of cement) on the various properties of flyash high strength concrete viz. compressive strength, split tensile strength, modulus of rupture, modulus of elasticity, poisson's ratio and shrinkage. ,For this purpose, 105 specimens (cubes, cylinders and prisms) were cast with various dosages of flyash. The compressive strength, split tensile strength, modulus of elasticity and modulus of rupture decreases with increase in percentage replacement of cement by flyash. The Poisson's ratio and initial drying shrinkage remain almost the same for different dosages of flyash in tlyash high strength concrete.