V. Nagendra, C. Sashidhar, S. M. Prasanna Kumar and N. Venkata Ramana

This paper presents the effect of Ground Granulated Blast Furnace Slag (GGBS) and NanoSilica (NS) as mineral admixtures in concrete, with specific size of particle passing through particular size of sieves along with varying dosages. The experimental work has been carried out in two stages. In the first stage the GGBS effect was studied as replacement to cement in various proportions of 10, 20, 30 and 40% and the size of particles for each replacement is varying from 20µm to 250 µm. At first stage the results showed that, at 20% replacement of cement, the strength is optimum for particle size of 20 µm. In the second stage the effective dosage of nanosilica along with GGBS was studied. In this stage (second) the 20% of GGBS was taken as constant and the nanosilica was varied in the proportion of 2, 4 and 6%. From all the results it is noticed that, GGBS addition with nanosilica for concrete has yielded the maximum strength at 4%NS and 20% GGBS replacement for 20µm particle size.