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

Abstract

h i g h l i g h t sSNPs shows its maximum nucleation effect at 8 h when the rate of product formation is high than the control. Maximum pozzolanic effect of SNPs observed at 24 h when the quantity of CH was lower than the control. $25% addition C-S-H formed in the presence of SNPs at 24 h. More polymerized and well ordered crystalline C-S-H is formed in presence of SNPs. SNPs formed more compact and dense microstructure at 24 h which is responsible for the higher early age mechanical strength. a b s t r a c tThe beneficial role of silica nano-particles (SNPs) during the early stage hydration of tricalcium silicate (C 3 S) 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.

Effect of Nano-SiO2 on the Early Hydration of Alite-Sulphoaluminate Cement

“…Each peak shift and intensity was monitored and carefully analyzed. For comparison, the peaks of CH (2 θ = 18°) and crystalline C–S–H (2 θ = 50.7°, jennite and tobermorite) [ 51 ] were first selected (see grey area in Figure 5 ). In Figure 5 , a peak in CH was observed in the N0 mix representing the hydration product (CH), which was released during the hydration of the AC$A cement.…”

Characteristics of Ordinary Portland Cement Using the New Colloidal Nano-Silica Mixing Method

“…The nano-silica particles were not observed in 50% CNS gypsum because gypsum and portlandite were consumed by the formation of ettringite by the pozzolanic reaction [8,20,27,31]. The pozzolanic reaction is further promoted as the number of nano-silica particles increased [49][50][51][52]. However, as shown in Figure 5b, there was no change in the size of the C-S-H peak from 1-day to 28-days, even in case of the 50% CNS specimen.…”

Hydration Properties of Portland Cement Paste with Boron Gangue

“…Figures 9 and 10 show the diffraction patterns of C 3 A and C 3 S with and without boron gangue, and there are significant differences about the mineralogical compositions of C 3 A or C 3 S with and without boron gangue. Based on the Advances in Materials Science and Engineering reports of pure C 3 A hydration [28] and pure C 3 S hydration [29], the hydration process can be described in five steps ( Figure 11).…”