Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-28T01:37:21.379Z Has data issue: false hasContentIssue false

The Effect of Silica Polymerization in Fly Ash on the Strength of Geopolymers

Published online by Cambridge University Press:  30 July 2014

N. Koshukhova
Affiliation:
The Belgorod State Technological University named after V.G. Shoukhov, Russia.
I. Zhernovsky
Affiliation:
The Belgorod State Technological University named after V.G. Shoukhov, Russia.
K. Sobolev
Affiliation:
Department of Civil Engineering and Mechanics, University of Wisconsin-Milwaukee, USA.
Get access

Abstract

The formation of the structure of geopolymer binders based on low-calcium fly ash is a multifactorial process that depends on the degree of solubility of aluminosilicate components in the solution of alkali activator. It is observed that the geopolymer binders based on fly ash with an identical chemical and mineral composition, the same grain size, and also activated by the same alkalis can result in a different strength.

This study is based on the assumption that there is dependence between the solubility of aluminosilicate components and the degree of polymerization of the silicates in glass phase. The degree of SiO2-polymerization is an integral parameter that is equal to the Si molar ratio (fSi) of the silicate component in the glass phase of fly ash. The degree of SiO2-polymerization can be estimated from the molar composition of glass phase, which is determined from the chemical composition and quantitative X-ray diffraction analysis including identification of the amorphous phase composition.

The SiO2 polymerization rates of investigated fly ash specimens are confirmed by the IR results, specifically, by comparison of absorption bands of silicate fragments with varying levels of connectivity (Q0-4) in the range of wave numbers of 650–1350 cm-1.

The comparative analysis of the correlation of 28-day strength of geopolymer binders based on fly ash from different sources and level of SiO2-polymerization demonstrated an inverse relationship with fSi molar ratio and compressive strength.

Type
Articles
Copyright
Copyright © Materials Research Society 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Fernández-Jiménez, A., Palomo, A., Alkali-Activated Fly Ashes: Properties and Characteristics, edited by Grieve, G., Owens, G., (Proc. of 11th Int. Cong. on Chem. Cem. Vol. 3, Durban, South Africa, 2003) pp. 13221340 Google Scholar
Criado, M., Fernandez-Jimenez, A., de la Torre, A.G., Aranda, M.A.G., Palomo, A., Cement Concrete Res. 37, 671679 (2007).CrossRefGoogle Scholar
Duxson, P., Provis, J.L., Lukey, G.C., Mallicoat, S.W., Kriven, W.M., van Deventer, J.S.J., Colloids Surf. A 269, 4758 (2005).CrossRefGoogle Scholar
Fernández-Jiménez, A., Palomo, A., Fuel 82, 18, 22592265 (2003).CrossRefGoogle Scholar
Fernández-Jiménez, A., de la Torre, A.G., Palomo, A., López-Olmo, G., Alonso, M.M., Aranda, M.A.G., Fuel 85, 19601969 (2006).CrossRefGoogle Scholar
Škvára, F., Jílek, T., Kopecký, L., Ceram−Silikáty 49 (3), 195204 (2005).Google Scholar
Appen, A.A., Chemistry of Glass (Chemistry Publishing, Leningrad, USSR, 1974), in Russian .Google Scholar
Glukhovsky, V. D., Krivenko, P.V., Starchuk, V.N., Pashkov, I.A. and Chrkova, V.V.,Slag Alkaline Concretes Made with Fine Aggregates, edited by Glukhovsky (Kiev, USSR: Vysscha Sckola Publisher, 1981), in Russian .Google Scholar
Solovyov, L.A., J. Appl. Crystallogr. 37, 743749 (2004).CrossRefGoogle Scholar
Anphilogov, V.N., Byikov, V.N., Osipov, A.A., Silicate Melts, edited by Votyakov, S.L. (Science Publisher, Moscow, 2005), in Russian .Google Scholar