An Experimental Investigation On Partial Replacement Of Cement With Silica Fume

Abstract

The Construction Activities In Last Few Decades Have Increased Very Well In Almost All The Developing Countries Of The World. Cement Is Becoming A Scarce Commodity Globally Because Of Its Growing Demand Day By Day. It Is The Need Of Time To Search Such Alternative Materials That Would Partially Or Fully Replace Cement Used In Concretes And Mortars Without Affecting Its Quality, Strength And Other Characteristics. By Addition Of Some Pozzolanic Materials, The Various Properties Of Concrete Viz Can Be Improved. Silica Fume Is Known To Improve Both The Mechanical Properties And Durability Of Concrete. The Principle Physical Effect Of Silica Fume In Concrete Is That Of Filler Besides The Pozzolanic Activity, Which Because Of Its Fineness Can Fit Into Space Between Cement Grains In The Same Way That Sand Fills The Space Between Particles Of Coarse Aggregates And Cement Grains Fill The Space Between Sand Grains. In This Experimental Investigation An Attempt Has Been Made To Determine The Effects Of Silica Fume On M30 Grade Concrete. This Investigation Involves Partial Replacement Of Cement With Silica Fume Varying Proportion Of 0%,5%,10%, 15% By Weight Of Cement. The Characteristics Of Fresh Concrete Are Determined By Slump Cone Test To Find The Work Ability Of The Concrete, And Hardened Properties Of Concrete Such As Compressive Strength, Flexural Strength, Tensile Strength Were Carried Out At 7 Days And 28 Days For Various Proportions Of Silica Fume. The Results Of Various Tests Conducted On Control Mix And Other Mixes With Different Proportions Of Silica Fume Have Been Compared. The Results Of Experimental Investigation Indicates That The Use Of Silica Fume In Concrete Has Increased The Strength And At Allage When Compared To Normal Concrete. The Workability Of Concrete Is Decreasing With Increasing Silica Fume Content ,thus The Concrete Containing Silica Fume Require More Water Than The Conventional Concrete. The Strength Of Concrete Increases Rapidly As We Increases The Silica Fume Content And The Optimum Value Of Compressive Strength, Flexural Strength, Split Tensile Strength Is Obtained At 10% Replacement, After 10% Its Start Decreasing.

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