Composition, morphology and nanostructure of C-S-H in 70% white Portland cement-30% fly ash blends hydrated at 55 {sup o}C

Journal Article · Wed Sep 15 00:00:00 EDT 2010 · Cement and Concrete Research

DOI:https://doi.org/10.1016/j.cemconres.2010.03.012· OSTI ID:21418102

Girao, A V ^[1]; Taylor, R ^[1]; Brydson, R M.D. ^[2]

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1. School of Civil Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)
2. Institute for Materials Research, University of Leeds, Leeds LS2 9JT (United Kingdom)

Outer product C-S-H had a mixture of fibrillar and foil-like morphology in a 28-day-old water-activated paste, and foil- or lath-like morphology in an alkali-activated paste. It was not possible to determine the chemical composition of C-S-H using SEM-EDX because of fine-scale intermixing with other phases; TEM-EDX was necessary. The C-S-H formed in the alkali-activated paste had a lower mean Ca/(Al + Si) ratio than that formed with water. The mean length of the aluminosilicate anions in the C-S-H was similar in both systems and increased with age; those in the Op C-S-H were likely to be shorter than those present in the Ip C-S-H with water activation, but longer (and more protonated) with alkali. The potassium in the alkali-activated paste was present either within the C-S-H structure charge balancing the substitution of Al{sup 3+} for Si{sup 4+}, or adsorbed on the C-S-H charge balancing sulfate ions.

• OSTI ID: 21418102
• Journal Information: Cement and Concrete Research, Vol. 40, Issue 9; Other Information: DOI: 10.1016/j.cemconres.2010.03.012; PII: S0008-8846(10)00081-5; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0008-8846
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
36 MATERIALS SCIENCE
ALUMINIUM IONS
ANIONS
CHEMICAL COMPOSITION
FLY ASH
FOILS
MORPHOLOGY
NANOSTRUCTURES
NUCLEAR MAGNETIC RESONANCE
PORTLAND CEMENT
POTASSIUM
SCANNING ELECTRON MICROSCOPY
SILICON IONS
SULFATES
TEMPERATURE RANGE 0273-0400 K
TRANSMISSION ELECTRON MICROSCOPY
WATER
AEROSOL WASTES
ALKALI METALS
ASHES
BUILDING MATERIALS
CEMENTS
CHARGED PARTICLES
COMBUSTION PRODUCTS
ELECTRON MICROSCOPY
ELEMENTS
HYDROGEN COMPOUNDS
IONS
MAGNETIC RESONANCE
MATERIALS
METALS
MICROSCOPY
OXYGEN COMPOUNDS
RESIDUES
RESONANCE
SULFUR COMPOUNDS
TEMPERATURE RANGE
WASTES