Studies on early stage hydration of tricalcium silicate incorporating silica nanoparticles: Part II

The beneficial role of silica nano-particles (SNPs) during the early stage hydration of tricalcium silicate (C3S) has been investigated. ICP results show that SNPs significantly accelerate the hydration rate as well as the growth of hydrated products, by providing additional nucleating sites. XRD results also show a dominant nucleation effect of SNPs up to 10 h. While, at later stage i.e. from 15 to 24 h, the pozzolanic effect of SNPs was dominant. Further, TGA results reveal that, in SNPs incorporated samples, quantity of CH is higher (∼61% at 8 h) up to 10 h, and lower (∼32% at 24 h) from 15 to 24 h than the control, showing the nucleation and pozzolanic effect of SNPs respectively. FTIR and XRD results further reveal an accelerated formation of crystalline C-S-H (jennite and tobermorite) with SNPs. All these results i.e. accelerated hydration, crystalline C-S-H formation and lower C/S (∼1.9) lead to enhanced durability of cementitious materials.