Study on Effect of Silica Fume on Properties of M40 Grade of Concrete

Abstract

One of promising new field of science is nanotechnology. Concrete being one of the most largely used material is also being modified for the better by introduction of nanomaterials like nano-silica, nano-alumina etc. The present study incorporates silica fume as partial replacement of cement. In this study, properties such as Compressive strength, Split tensile strength, Flexural strength and Sulphate resistance of M40 grade of concrete using micro silica are studied. The cement (OPC Grade 43) was replaced by 0%, 5%, 8%, 10%, 12%, and 15% silica fume. The cubical specimens of standard size (150mm) were casted and tested at 7, 14 and 28 days respectively to calculate compressive strength. The results showed that 8% replacement of cement by silica fume gave maximum compressive strength and beyond that compressive strength of the specimen decreased. For split tensile and flexural strength, cylindrical specimens (300×150) mm and beam specimens (750×150×150) mm were casted respectively. For sulphate resistance, cement is replaced by 0%, 5%, 8% and 15% silica fume and standard cubical specimens were casted. The tests for split tensile strength, flexural strength were performed on standard specimens at 7, 14 and 28 days. The results showed Silica Fume has marginal effect on these properties. The cubical specimens were tested for sulphate resistance at 7, 28 and 56 days respectively. The results showed that 8% replacement of cement by Silica fume gives less loss of compressive strength at all ages.