Skip to main content

Effect of Sodium Silicate to Sodium Hydroxide Ratios on Strength and Microstructure of Fly Ash Geopolymer Binder

Abstract

Geopolymerization can transform a wide range of waste aluminosilicate materials into building and mining materials with excellent chemical and physical properties. The present experimental study investigates the effect of sodium silicate/sodium hydroxide ratios on the feasibility of geopolymer synthesis at 80 °C using fly ash. The sodium silicate/sodium hydroxide (S/N) ratios 0.5, 1.0, 1.5, 2.0 and 2.5 were studied. The result showed that the compressive and flexural strength increases as the curing age increases. Also, the compressive strength increases as the sodium silicate/sodium hydroxide ratio increases from 0.5 to 1.0 and then decreases. Morphology studies, conducted by SEM analysis of the geopolymer samples, indicated that geopolymers gel had the fly ash particles and pores embedded in a continuous matrix. At S/N = 1 a homogeneous and less porous microstructure was observed.

This is a preview of subscription content, access via your institution.

References

  1. Kong D.L.Y., Sanjayan J.G.: Damage behavior of geopolymer composites exposed to elevated temperature. Cem. Conc. Compos. 30, 986–991 (2008)

    Article  Google Scholar 

  2. Davidovits, J.: High alkali cements for 21st Century concretes. Concrete technology, past, present, and future, SP-144. In: Mehta, K. (ed.), American Concrete Institute, Detroit, pp. 383–397 (1994a)

  3. Davidovits, J.: Properties of geopolymer cement. In: Škvára, F. (ed.) Proceedings of 1st International Conference on Alkaline Cements and Concretes, Scientific Research Institute on Binders and Materials, Kiev State Technical University, Kiev, pp. 131–149 (1994b)

  4. Lyon R.E., Foden A., Balaguru P.N., Davidovits M., Davidovits J.: Fire-resistant aluminosilicate composites. Fire Mater. 21, 67–73 (1997)

    Article  Google Scholar 

  5. Li Z., Zhang Y., Zhou X.: Short fiber reinforced geopolymer composites manufactured by extrusion. J. Materi. Civil Eng. 17, 624–631 (2005)

    Article  Google Scholar 

  6. Xu H., Van Deventer J.S.J.: The geopolymerisation of alumino-silicate minerals. Int. J. Miner. Process 59, 247–266 (2000)

    Article  Google Scholar 

  7. De Silva, P.; Sagoe-Crenstil, K.; Sirivivatnanon, V.: Kinetics of geopolymerization: role of Al2O3 and SiO2. Cem. Conc. Res. 37, 512–518 (2007)

    Google Scholar 

  8. Phair J.W., Van Deventer J.S.J.: Effect of silicate activator pH on the leaching and material characteristics of wast-baste-based inorganic polymers. Miner. Eng. 14, 289 (2001)

    Article  Google Scholar 

  9. Mohsen Q., Mostafa N.Y.: Investigating the possibility of utilizing low kaolinitic clays in production of geopolymer bricks. Ceramics Silikáty 54, 160–168 (2010)

    Google Scholar 

  10. Palomo A., Grutzec M.W., Blanco M.T.: Alkali-activated fly ashes A cement for the future. Cem. Conc. Res. 29, 1323–1329 (1999)

    Article  Google Scholar 

  11. Provis J.L., Lukey G.C., Van Deventer J.S.J.: Do geopolymers activity contain nanocrystalline zeolites. Chem. Mater. 17, 3075–3085 (2005)

    Article  Google Scholar 

  12. Davidovits J., Comrie D.C., Paterson J.H., Ritcey D.J.: Geopolymeric concretes for environmental protection. Conc. Int. 12, 30–40 (1990)

    Google Scholar 

  13. Xu H., Jannie S., Van Deventer J.S.J.: Geopolymerisation of multiple minerals. Miner. Eng. 15, 1131–1139 (2002)

    Article  Google Scholar 

  14. Phair J.W., Van Deventer J.S.J.: Effect of silicate activator pH on the microstructural characteristics of waste-based geopolymers. Int. J. Miner. Process 66, 121–143 (2002)

    Article  Google Scholar 

  15. Komnitsas, K.; Zaharaki, D.; Perdikatsis, V.: Geopolymerisation of low calcium ferronickel slags. J. Mater. Sci. 42, 3073 (2007)

    Google Scholar 

  16. Skvara F., Kopecky L., Nimeeek J., Bittnar Z.: Microstructure of geopolymer materials based on fly ash. Ceramics Silikaty 50, 208–215 (2006)

    Google Scholar 

  17. Hardjito D., Cheak C.C., Lee I.C.H.: Strength and setting time of low calcium fly ash-based geopolymer mortar. Mod. Appl. Sci. 2, 3–11 (2008)

    Article  Google Scholar 

  18. Jaarsveld J.G.S.V., Deventer J.S.J.V., Lukey G.C.: The effect of composition and temperature on the properties of fly-ash and kaolinite-based geopolymers. Chem. Eng. J. 89, 63–73 (2002)

    Article  Google Scholar 

  19. Davidovits, J.: Geopolymer chemistry and applications. 2nd ed. Institute Geopolymere, Saint Quentin (2008)

  20. Alonso S., Palomo A.: Calorimetric study of alkaline activation of calcium hydroxide-metakaolin solid mixtures. Cem. Conc. Res. 31, 25–30 (2001)

    Article  Google Scholar 

  21. Rattanasak U., Chindaprasirt P.: Influence of NaOH solution on the synthesis of fly ash geopolymer. Miner. Eng. 22, 1073–1078 (2009)

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to M. S. Morsy.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Morsy, M.S., Alsayed, S.H., Al-Salloum, Y. et al. Effect of Sodium Silicate to Sodium Hydroxide Ratios on Strength and Microstructure of Fly Ash Geopolymer Binder. Arab J Sci Eng 39, 4333–4339 (2014). https://doi.org/10.1007/s13369-014-1093-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13369-014-1093-8

Keywords

  • Geopolymer
  • Microstructure
  • Compressive strength
  • Flexural strength