Effect of Silica Fume on the Properties of Concrete

Abstract

In the present paper, experimental results on workability, compressive strength and permeability of concrete with various mixture proportions have been presented to study the effect of silica fume on concrete mixes. It has been found that microsilica increases the workability of the fresh concrete upto a certain limit of microsilica addition (upto 20%) as cement replacement. Compressive strength was also increased on addition of microsilica. The Ultrasonic Pulse Velocity results showed that during initial compression the UPV was increased slightly but on further increasing the compressive load the UPV was decreased. When the load was about 75-80 percent of ultimate strength, an abrupt reduction in UPV was observed. It has been found from the study that addition of micro silica (upto 20%) in concrete reduces the permeability by 35%-50%.