High strength sustainable concrete using silica nanoparticles

This study deals with the effect of silica nanoparticles (SNPs) in high volume fly ash (40% replacement) cement paste, mortar and concrete. The content of SNPs (0.5-3.0%) was added by the weight of binder and w/b ratio (0.23, 0.25 & 3.0) was optimized in paste and mortar system. The calorimetric results reveal that the hydration process was accelerated as a result of SNPs incorporation and the dormant period was shortening by 4 h with 2% SNPs as compared to the control. The effect of optimum dosages of SNPs addition on concrete in terms of mechanical and durability properties was studied at 0.25 w/b ratio. The compressive strength results of SNPs added mixtures showed an improvement of 61% at 3 days and 25% at 28 days of hydration as compared to control. The durability studies at 28 day showed that, with the incorporation of SNPs, the porosity, sorptivity and water absorption reduced up to 25-40% and densify the interfacial transition zone (ITZ).