Effect of silica particle size on the formation of calcium silicate hydrate [C-S-H] using thermal analysis

Riccardo Maddalena, Christopher Hall, Andrea Hamilton

Research output: Contribution to journalArticle

13 Citations (Scopus)
34 Downloads (Pure)

Abstract

Calcium silicate hydrate (C-S-H) is made by mixing calcium hydroxide (portlandite), silica and water at two calcium oxide to silica (C/S) ratios, using nano-silica and silica fume. We investigate how silica particle size influences the rate and extent of formation of C-S-H at room temperature by isothermal calorimetry, thermal analysis, Raman spectroscopy and X-ray diffraction. Rate of reaction increases as silica particle size decreases, and is five times greater with nano-silica than with silica fume. Final composition depends only on initial C/S ratio. Compositions at 28 days are estimated from thermogravimetric and X-ray diffraction data. There is a weak maximum in the reaction rate of nanosilica pastes about 20–30 h after mixing. The overall kinetics is well described by a simple exponential (first-order) reaction model. The early-time reaction rate around the rate maximum is described by an Avrami model.

Original languageEnglish
Pages (from-to)142-149
Number of pages8
JournalThermochimica acta
Volume672
Early online date7 Sep 2018
DOIs
Publication statusPublished - 28 Feb 2019

Keywords

  • calcium silicate hydrate
  • nano-silica
  • silica fume
  • heat of hydration
  • calorimetry
  • Raman spectra

Fingerprint Dive into the research topics of 'Effect of silica particle size on the formation of calcium silicate hydrate [C-S-H] using thermal analysis'. Together they form a unique fingerprint.

Cite this