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Journal of Materials Science

, Volume 46, Issue 20, pp 6545–6555 | Cite as

Micromechanical multiscale model for alkali activation of fly ash and metakaolin

  • Vít Šmilauer
  • Petr Hlaváček
  • František Škvára
  • Rostislav Šulc
  • Lubomír Kopecký
  • Jiří Němeček
Article

Abstract

The process of alkali activation of fly ash and metakaolin is examined in the view of micromechanics. Elasticity is predicted via semi-analytical homogenization methods, using a combination of intrinsic elastic properties obtained from nanoindentation, evolving volume fractions and percolation theory. A new quantitative model for volume fraction is formulated, distinguishing the evolution of unreacted aluminosilicate material, solid gel particles of N-A-S-H gel, and open porosity, which is partially filled with the activator. The stiffening of N-A-S-H gel is modeled by increasing the fraction of solid gel particles. Their packing density and intrinsic elasticity differ in N-A-S-H gels synthesized from both activated materials. Percolation theory helps to address the quasi-solid transition at early ages and explains a long setting time and the beneficial effect of thermal curing. The low ability of N-A-S-H gel to bind water chemically explains the high porosity of Ca-deficient activated materials. Micromechanical analysis matches well the elastic experimental data during the activation and elucidates important stages in the formation of the microstructure.

Keywords

Representative Volume Element Percolation Threshold Open Porosity Capillary Porosity Alkali Activation 

Notes

Acknowledgements

This research was supported by the Czech Science Foundation under the grant GAP104/10/2344, GA103/09/1748 and MSM 6046137302. M. Vokáč from Klokner Institute, CTU in Prague is greatly acknowledged for conducting precise measurements of elastic moduli.

References

  1. 1.
    Duxson P, Fernández-Jiménez A, Provis JL, Lukey GC, Palomo A, van Deventer JSJ (2007) J Mater Sci 42(9):2917. doi: https://doi.org/10.1007/s10853-006-0637-z CrossRefGoogle Scholar
  2. 2.
    Pacheco-Torgal F, Castro-Gomes J, Jalali S (2008) Constr Build Mater 22(7):1305CrossRefGoogle Scholar
  3. 3.
    van Deventer JSJ (eds) (2009) Geopolymers: structures, processing, properties and industrial applications, 1st edn. Woodhead Publishing Ltd, CambridgeGoogle Scholar
  4. 4.
    Fernández-Jiménez A, Palomo A (2005) Cem Concr Res 35:1984CrossRefGoogle Scholar
  5. 5.
    Hardjito D, Rangan BV (2005) Research report gc 1. Faculty of Engineering, Curtin University of Technology, PerthGoogle Scholar
  6. 6.
    Wallah SE, Rangan BV (2006) Research Report GC 2. Curtin University of Technology, PerthGoogle Scholar
  7. 7.
    Kovalchuk G, Fernandez-Jimenez A, Palomo A (2007) Fuel 86(3):315CrossRefGoogle Scholar
  8. 8.
    Škvára F, Kopecký L, Šmilauer V, Bittnar Z (2009) J Hazard Mater 168:711CrossRefGoogle Scholar
  9. 9.
    Davidovits J (2001) In: Metha PK (ed) Concrete technology, past, present and future, Proceedings of V. Mohan Malhotra Symposium, ACI, p 383Google Scholar
  10. 10.
    van Jaarsveld JGS, van Deventer JSJ, Lorenzen L (1997) Miner Eng 10(7):659CrossRefGoogle Scholar
  11. 11.
    Criado M, Fernández-Jiménez A, Palomo A (2010) Fuel 89(11):3185CrossRefGoogle Scholar
  12. 12.
    Fernández-Jiménez A, Palomo A, Criado M (2004) Cem Concr Res 35:1204CrossRefGoogle Scholar
  13. 13.
    Chen C, Gong W, Lutze W, Pegg I, Zhai J (2011) J Mater Sci 46(3):590. doi: https://doi.org/10.1007/s10853-010-4997-z CrossRefGoogle Scholar
  14. 14.
    Provis JL, van Deventer JSJ (2007) Chem Eng Sci 62:2309CrossRefGoogle Scholar
  15. 15.
    Powers TC, Brownyards TL (1948) Studies of physical properties of hardened portland cement paste. Bulletin 22, Research Laboratories of the Portland Cement Association, ChicagoGoogle Scholar
  16. 16.
    Bernard O, Ulm FJ, Lemarchand E (2003) Cem Concr Res 33(9):1293CrossRefGoogle Scholar
  17. 17.
    Šmilauer V, Bittnar Z (2006) Cem Concr Res 36(9):1708CrossRefGoogle Scholar
  18. 18.
    Pichler C, Lackner R, Mang HA (2007) Eng Fract Mech 74:34CrossRefGoogle Scholar
  19. 19.
    Grassl P, Jirásek M (2010) Int J Solids Struct 47(7–8):957CrossRefGoogle Scholar
  20. 20.
    Šejnoha M, Zeman J (2008) Int J Eng Sci 46(6):513; special Issue: Micromechanics of Materials. doi: https://doi.org/10.1016/j.ijengsci.2008.01.006 CrossRefGoogle Scholar
  21. 21.
    Němeček J, Šmilauer V, Kopecký L (2011) Cem Concr Compos 33(2):163CrossRefGoogle Scholar
  22. 22.
    Perera D, Uchida O, Vance E, Finnie K (2007) J Mater Sci 42(9):3099. doi: https://doi.org/10.1007/s10853-006-0533-6 CrossRefGoogle Scholar
  23. 23.
    Zaoui A (2002) J Eng Mech 128(8):808CrossRefGoogle Scholar
  24. 24.
    Mori T, Tanaka K (1973) Acta Metall 21(5):1605CrossRefGoogle Scholar
  25. 25.
    Hill R (1965) J Mech Phys Solids 13:189CrossRefGoogle Scholar
  26. 26.
    Palomo A, Grutzeck MW, Blanco MT (1999) Cem Concr Res 29:1323CrossRefGoogle Scholar
  27. 27.
    Provis JL, van Deventer JSJ (2007) Chem Eng Sci 62:2318CrossRefGoogle Scholar
  28. 28.
    Rodríguez E, de Gutiérrez RM, Bernal S, Gordillo M (2009) Rev Fac Ing 49:30Google Scholar
  29. 29.
    Strnad T (2011) PhD thesis, Faculty of Civil Engineering, Czech Technical University (in Czech)Google Scholar
  30. 30.
    Rahier H, Denayer JF, van Mele B (2003) J Mater Sci 38:3131. doi: https://doi.org/10.1023/A:1024733431657 CrossRefGoogle Scholar
  31. 31.
    Powers TC (1958) J Am Ceram Soc 41(1):1CrossRefGoogle Scholar
  32. 32.
    Duxson P, Provis JL, Lukey GC, Mallicoat SW, Kriven WM, van Deventer JSJ (2005) Colloids Surf A 269:47CrossRefGoogle Scholar
  33. 33.
    Scherer GW (1999) Cem Concr Res 29(8):1149CrossRefGoogle Scholar
  34. 34.
    Constantinides G, Ulm FJ (2007) J Mech Phys Solids 55:64CrossRefGoogle Scholar
  35. 35.
    Jennings HM (2008) Cem Concr Res 38(3):275CrossRefGoogle Scholar
  36. 36.
    Wongpa J, Kiattikomol K, Jaturapitakkul C, Chindaprasirt P (2010) Mater Des 31(10):4748CrossRefGoogle Scholar
  37. 37.
    Matsunaga T, Kim JK, Hardcastle S, Rohatgi PK (2002) Mater Sci Eng A 325(1–2):333CrossRefGoogle Scholar
  38. 38.
    van Deventer J, Provis J, Duxson P, Lukey G (2007) J Hazard Mater 139(3):506CrossRefGoogle Scholar
  39. 39.
    Neubauer CM, Jennings HM, Garboczi EJ (1997) Cem Concr Res 27(10):1603CrossRefGoogle Scholar
  40. 40.
    Neville AM (1997) Properties of concrete. Wiley, New YorkGoogle Scholar
  41. 41.
    Šmilauer V (2011) Multiscale hierarchical modeling of hydrating concrete. Saxe-Coburg Publications, StirlingGoogle Scholar
  42. 42.
    Chen C, Gong W, Lutze W, Pegg I (2011) J Mater Sci 46(9):3073. doi: https://doi.org/10.1007/s10853-010-5186-9 CrossRefGoogle Scholar
  43. 43.
    Duxson P, Mallicoat SW, Lukey GC, Kriven WM, van Deventer JSJ (2007) Colloids Surf A 292(1):8CrossRefGoogle Scholar
  44. 44.
    Kirschner AV, Harmuth H (2004) Ceram-Silik 48(3):117Google Scholar
  45. 45.
    Barbosa VFF, MacKenzie KJD, Thaumaturgo C (2000) Int J Inorg Mater 2(4):309CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Vít Šmilauer
    • 1
  • Petr Hlaváček
    • 1
  • František Škvára
    • 2
  • Rostislav Šulc
    • 1
  • Lubomír Kopecký
    • 1
  • Jiří Němeček
    • 1
  1. 1.Faculty of Civil EngineeringCzech Technical University in PraguePrague 6Czech Republic
  2. 2.Department of Glass and CeramicsInstitute of Chemical Technology PraguePragueCzech Republic

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