Structures and phase relations of aluminum-substituted calcium silicate hydrate
- Pennsylvania State Univ., University Park, PA (United States). Intercollege Materials Research Lab.
The structures of aluminum-substituted calcium silicate hydrate (C-S-H) forming in a series of aqueous suspensions formulated with colloidal silica, reactive alumina, and lime and aged for 1 year have been studied using {sup 29}Si and {sup 27}Al magic angle spinning nuclear magnetic resonance spectroscopy (with and without cross polarization (CP)), solution pH, electron microscopy, and X-ray diffraction. As in earlier work dealing with the nature of C-S-H in the system CaO-SiO{sub 2}-H{sub 2}O, two aluminum-substituted C-S-H phases, having distinctly different anionic structures on the atomic level (Q{sub 2} versus Q{sub 1}Q{sub 2}), were found to extend into the system CaO-Al{sub 2}O{sub 3}-SiO{sub 2}-H{sub 2}O. X-ray diffraction patterns of the two aluminum-containing C-S-H phases are nearly identical, suggesting that their intermediate-range order is very similar, but MASNMR spectra show that these two phases have markedly different silicate structures on the atomic-level scale. Both C-S-H structures can accommodate approximately 5 mol% of Al{sub 2}O{sub 3} in tetrahedral and possibly octahedral coordination as well.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG02-91ER45456
- OSTI ID:
- 247915
- Journal Information:
- Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 4 Vol. 79; ISSN 0002-7820; ISSN JACTAW
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of Incorporating High-Volume Fly Ash into Tricalcium Silicate on the Degree of Silicate Polymerization and Aluminum Substitution for Silicon in Calcium Silicate Hydrate
Coordination environment of Si in calcium silicate hydrates, silicate minerals, and blast furnace slags: A XANES database