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

• Published in: Construction & building materials Vol. 102; pp. 943 - 949
• Main Authors: Singh, L.P., Bhattacharyya, S.K., Shah, S.P., Mishra, G., Sharma, U.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.01.2016; Elsevier B.V
• Subjects: Analysis; C-S-H; Hydration; Nanoparticles; Silica nano-particles; Silicates; Tricalcium silicate; United States; C-S-H; Hydration; Tricalcium silicate; Silica nano-particles
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2015.05.084

•SNPs shows its maximum nucleation effect at 8h when the rate of product formation is high than the control.•Maximum pozzolanic effect of SNPs observed at 24h when the quantity of CH was lower than the control.•∼25% addition C-S-H formed in the presence of SNPs at 24h.•More polymerized and well ordered crystalline C-S-H is formed in presence of SNPs.•SNPs formed more compact and dense microstructure at 24h which is responsible for the higher early age mechanical strength. 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 10h. While, at later stage i.e. from 15 to 24h, the pozzolanic effect of SNPs was dominant. Further, TGA results reveal that, in SNPs incorporated samples, quantity of CH is higher (∼61% at 8h) up to 10h, and lower (∼32% at 24h) from 15 to 24h 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.