Skip to main content Accessibility help
×
Home

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

  • N. Koshukhova (a1), I. Zhernovsky (a1) and K. Sobolev (a2)

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 (f Si ) 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 f Si molar ratio and compressive strength.

Copyright

References

Hide All
1. 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
2. Criado, M., Fernandez-Jimenez, A., de la Torre, A.G., Aranda, M.A.G., Palomo, A., Cement Concrete Res. 37, 671679 (2007).
3. 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).
4. Fernández-Jiménez, A., Palomo, A., Fuel 82, 18, 22592265 (2003).
5. Fernández-Jiménez, A., de la Torre, A.G., Palomo, A., López-Olmo, G., Alonso, M.M., Aranda, M.A.G., Fuel 85, 19601969 (2006).
6. Škvára, F., Jílek, T., Kopecký, L., Ceram−Silikáty 49 (3), 195204 (2005).
7. Appen, A.A., Chemistry of Glass (Chemistry Publishing, Leningrad, USSR, 1974), in Russian .
8. 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 .
9. Solovyov, L.A., J. Appl. Crystallogr. 37, 743749 (2004).
10. Anphilogov, V.N., Byikov, V.N., Osipov, A.A., Silicate Melts, edited by Votyakov, S.L. (Science Publisher, Moscow, 2005), in Russian .

Keywords

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

  • N. Koshukhova (a1), I. Zhernovsky (a1) and K. Sobolev (a2)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed