Effect of Lime on Mechanical Properties of Silica Fume Modified Concrete

Abstract

The sole objective of the work is aimed to examine the possibility of replacing ordinary Portland cement with condensed silica fume. Silica fume is a waste product from ferro-alloy silicon industry. In this research, the ordinary concrete has been modified by 25% of micro silica fume by replacing Portland cement. Again that same mix has been modified by adding free lime by replacing fine aggregate with different percentages like 3, 5, 7 and 10% by weight with a constant water-cement ratio 0.45 by weight. The cement and silica fume percentage was kept constant and after that the influence of addition of active lime was studied. The cement, sand and aggregate proportion were assumed as 1:1.5:3. Specimen was prepared for various tests like compressive, split-tensile and flexural strength for different curing ages (7, 28 and 56 days). Silica fume modified concrete with 7% of free lime by volume gave the best results.