Skip to main content
SpringerLink
Log in

Decalcification of alkali-activated slag pastes. Effect of the chemical composition of the slag

  • Original Article
  • Published:
Materials and Structures Aims and scope Submit manuscript

Abstract

Portland cement decalcification and its effects on paste microstructure and mechanical strength have been widely studied. Decalcification in alkali activated slag (AAS) pastes is still not fully understood, however. The present study therefore explored the process in AAS cement pastes, accelerated by submerging specimens in concentrated ammonium nitrate solutions (NH4NO3) for 3–21 days to induce leaching. Two AAS pastes were prepared with slag of different origins (Spanish and Colombian) and chemical compositions. OPC pastes were used as a reference. The findings showed that decalcification has a more adverse impact on OPC than AAS pastes strength. BSEM/EDX and 29Si MAS NMR data nonetheless confirmed that Ca leaches out of C–A–S–H gels (formed in AAS pastes) to an extent that depends on the nature of the prime material. OPC pastes were shown to generate more silica gel with a very low Ca content (Q3 and Q4 units). Moreover, the higher the percentage of such units, the lower was mechanical strength. Decalcification in slag with lower MgO and higher Al2O3 contents leads to the formation of smaller amounts of silica gel. The resulting gel was more compact and stable due to more intense chain cross-linking a possible tri-dimensional structure.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

References

  1. Ash JE, Hall MG, Langford JI, Mellas M (1993) Estimations of degree of hydration of Portland cement pastes. Cem Concr Res 23:399–406. doi:10.1016/0008-8846(93)90105-I

    Article  Google Scholar 

  2. Bascarevic Z, Komljenovic MM, Miladinovic Z, Nikolic V, Marjanovic N, Zujovic Z, Petrovic R (2013) Effects of the concentrated NH4NO3 solution on mechanical properties and structure of the fly ash based geopolymers. Constr Build Mater 41:570–579. doi:10.1016/j.conbuildmat.2012.12.067

    Article  Google Scholar 

  3. Ben Haha M, Lothenbach B, Le Saout G, Winnefeld F (2011) Influence of slag chemistry on the hydration of alkali-activated blast-furnace slag—Part I: Effect of MgO. Cem Concr Res. 41:955–963. doi:10.1016/j.cemconres.2011.05.002

    Article  Google Scholar 

  4. Ben Haha M, Le Saout G, Winnefeld F, Lothenbach B (2011) Influence of activator type on hydration kinetics, hydrate assemblage and microstructural development of alkali activated blast-furnace slags. Cem Concr Res. 41:301–310. doi:10.1016/j.cemconres.2010.11.016

    Article  Google Scholar 

  5. Bernal SA, Rodríguez ED, Mejía de Gutiérrez R, Provis JL (2012) Performance of alkali-activated slag mortars exposed to acids. J Sustain Cem Bas Mater 1(3):138–151. doi:10.1080/21650373.2012.747235

    Google Scholar 

  6. Bernal SA, Provis JL, Walkley B, San Nicolas R, Gehman JD, Brice DG, Kilcullen AR, Duxson P, Van Deventer JSJ (2013) Gel nanostructure in alkali-activated binders based on slag and fly ash, and effects of accelerated carbonation. Cem Concr Res 53:127–144. doi:10.1016/j.cemconres.2013.06.007

    Article  Google Scholar 

  7. Bernal SA, San Nicolas R, Myers RJ, Mejía de Gutierrez R, Puertas F, Van Deventer JSJ, Provis JL (2014) MgO content of slag controls phase evolution and structural changes induced by accelerated carbonation in alkali-activated binders. Cem Concr Res 57:33–43. doi:10.1016/j.cemconres.2013.12.003

    Article  Google Scholar 

  8. Engelhardt G, Michel D (1987) High resolution solid-state of silicates and zeolites. Wiley, New York

    Google Scholar 

  9. Fernández-Jiménez A, Palomo JG, Puertas F (1999) Alkali-activated slag mortars mechanical strength behavior. Cem Concr Res 29:1313–1321. doi:10.1016/S0008-8846(99)00154-4

    Article  Google Scholar 

  10. Fernández-Jiménez A, Puertas F (2001) Alkaline activated slag cements. Determination of reaction degree. Mater Constr 51(261):53–66. doi:10.3989/mc.2001.v51.i261.380

    Article  Google Scholar 

  11. Fernández-Jiménez A, Puertas F, Sobrados I, Sanz J (2003) Structure of calcium silicate hydrates formed in alkaline-activated slag: influence of the type of alkaline activator. J Am Ceram Soc 86(8):1389–1394. doi:10.1111/j.1151-2916.2003.tb03481.x

    Article  Google Scholar 

  12. Fernández-Jimenez A, Zibouche F, Boudissa N, García-Lodeiro I, Tahart Abadlia M, Palomo A (2013) Metakaolin-slag-clinker blends. The role of Na+ or K+ as alkaline activators of these ternary blends. J Am Ceram Soc 1–8. doi:10.1111/jace.12272

  13. Gadsden JA (1975) Infrared spectra of minerals and related inorganic compounds. Butterworth & CO Publishers, London

    Google Scholar 

  14. García-Díaz I, Puertas F, Gazulla MF, Gómez MP, Palacios M (2009) Effect of ZnO; ZrO2 y B2O3. Part II. Phase separation and clinker phase distribution. Mater Constr 59(294):53–74. doi:10.3989/mc.2009.46308

    Article  Google Scholar 

  15. Goñi S, Guerrero A, Puertas F, Hernández MS, Palacios M, Dolado JS, Zhu W, Howind T (2011) Textural and mechanical characterization of C–S–H gels from hydration of synthetic T1-C3S, β-C2S and their blends. Mater Constr 61(302):169–183. doi:10.3989/mc.2011.00511

    Article  Google Scholar 

  16. Haga K, Sutou S, Hironaga M, Tanaka S, Nagasaki S (2005) Effects of porosity on leaching of Ca from hardened ordinary Portland cement paste. Cem Concr Res 35:1764–1775. doi:10.1016/j.cemconres.2004.06.034

    Article  Google Scholar 

  17. Harris AW, Manning MC, Tearle WM, Tweed CJ (2002) Testing of models of the dissolution of cements-leaching of synthetic C–S–H gels. Cem Concr Res 32:731–746. doi:10.1016/S0008-8846(01)00748-7

    Article  Google Scholar 

  18. Heukamp FH, Ulm FJ, Germain JT (2001) Mechanical properties of calcium-leached cement pastes. Triaxial stress states and the influence of the pore pressures. Cem Concr Res 31:767–774. doi:10.1016/S0008-8846(01)00472-0

    Article  Google Scholar 

  19. Hooton RD, Emery JJ (1983) Glass Content determination and strength development predictions for vitrified blast furnace slag. ACI Mater J. Tech Pap 79:943–962

    Google Scholar 

  20. Jennings HM (2000) A model for the microstructure of calcium silicate hydrate in cement paste. Cem Concr Res 30:101–116. doi:10.1016/S0008-8846(99)00209-4

    Article  Google Scholar 

  21. Komljenovic MM, Bascarevic Z, Marjanovic N, Nikolic V (2012) Decalcification resistance of alkali-activated slag. J Hazard Mater 233–234:112–121. doi:10.1016/j.jhazmat.2012.06.063

    Article  Google Scholar 

  22. Le Saout G, Ben Haha M, Winnefeld F, Lothenbach B (2011) Hydration degree of alkali-activated slags: a 29Si NMR study. J Am Ceram Soc. 94(12):4541–4547. doi:10.1111/j.1551-2916.2011.04828.x

    Article  Google Scholar 

  23. Massiot D, Fayon F, Capron M, King J, Le Calve S, Alonso B, Durand JO, Bujoli B, Gan Z, Hoatson G (2002) Modelling one and two dimensional solid state NMR spectra. Magn Reson Chem 40:70–76. doi:10.1002/mrc.984

    Article  Google Scholar 

  24. Myers RJ, Bernal SA, San Nicolas R, Provis JL (2013) Generalized structural description of calcium-sodium aluminosilicate hydrate gels: the cross-linked substituted tobermorite model. Langmuir 29:5294–5306. doi:10.1021/la4000473

    Article  Google Scholar 

  25. Nakamoto K (1963) Infrared spectra of inorganic and coordination compounds. Wiley, London

    Google Scholar 

  26. Palacios M, Puertas F (2006) Effect of carbonation on alkali-activated slag pastes. J Am Ceram Soc 89(10):3211–3221. doi:10.1111/j.1551-2916.2006.01214.x

    Article  Google Scholar 

  27. Palomo A, Blanco-Varela MT, Granizo ML, Puertas F, Vazquez T, Grutzeck MW (1999) Chemical stability of cementitious materials based on metakaolin. Cem Concr Res 29(7):997–1004. doi:10.1016/S0008-8846(99)00074-5

    Article  Google Scholar 

  28. Puertas F (1995) Cementos de escorias activadas alcalinamente: Situación actual y perspectivas de futuro. Mater Constr 45(239):53–64. doi:10.3989/mc.1995.v45.i239.553

    Article  Google Scholar 

  29. Puertas F, Fernández-Jiménez A, Blanco-Varela MT (2004) Pore solution in alkali-activated slag cements pastes. Relation to the composition and structure of calcium silicate hydrate. Cem Concr Res 34:139–148. doi:10.1016/S0008-8846(03)00254-0

    Article  Google Scholar 

  30. Puertas F, Palacios M, Manzano H, Dolado JS, Rico A, Rodríguez J (2011) A model for the C–A–S–H gel formed in alkali-activated slag cements. J Eur Ceram Soc 31:2043–2056. doi:10.1016/j.jeurceramsoc.2011.04.036

    Article  Google Scholar 

  31. Puertas F, Goñi S, Hernández MS, Varga C, Guerrero A (2012) Comparative study of accelerated decalcification process among C3S, grey and white cement pastes. Cem Concr Compos. 34(3):384–391. doi:10.1016/j.cemconcomp.2011.11.002

    Article  Google Scholar 

  32. Puertas F, Goñi S, Hernández MS, Varga C, Guerrero A (2012) Accelerated decalcification in C3S, grey and white cement pastes. Effect on the micro and nanostructure of C–S–H. In: NICOM 4: 4th international symposium on nanotechnology in construction, Agios Nikolaos, Crete, Greece

  33. Richarson IG (1999) The nature of C–S–H in hardened cements. Cem Concr Res 29:1131–1147. doi:10.1016/S0008-8846(99)00168-4

    Article  Google Scholar 

  34. Short NR, Brough A, Seneviratne AMG, Purnell P, Page CL (2004) Preliminary investigations of the phase composition and fine pore structure of super-critically carbonated cement pastes. J Mater Sci 39:5683–5689. doi:10.1023/B:JMSC.0000040076.42260.cb

    Article  Google Scholar 

  35. Shi C, Stegemann JA (2000) Acid corrosion resistance of different cementing materials. Cem Concr Res 30:803–808. doi:10.1016/S0008-8846(00)00234-9

    Article  Google Scholar 

  36. Taylor HFW (1997) Cement chemistry. Thomas Telford, London. doi:10.1680/cc.25929

    Book  Google Scholar 

  37. Wan K, Li I, Sun W (2013) Solid–liquid equilibrium curve of calcium in 6 mol/L ammonium nitrate solution. Cem Concr Res 53:44–50. doi:10.1016/j.cemconres.2013.06.003

    Article  Google Scholar 

  38. Wang SD, Scrivener KL, Pratt PL (1994) Factors affecting the strength of alkali-activated slag. Cem Concr Res 24:1033–1043. doi:10.1016/0008-8846(94)90026-4

    Article  Google Scholar 

  39. Zhang YR, Ying GQ, Xi OS (1988) Study on structure and latent hydraulic activity of slag and its activation mechanism. Silic Indus 3–4:55–59

    Google Scholar 

Download references

Acknowledgments

The authors wish to thank to MINECO for funding the Project BIA2010-15516. The authors wish also to thank P. Rivilla and M. Torres-Carrasco, for their assistance with the tests.

Author information

Authors and Affiliations

  1. Eduardo Torroja Institute for Construction Science (IETcc-CSIC), Madrid, Spain

    C. Varga, M. M. Alonso & F. Puertas

  2. School of Materials Engineering, Composite Materials Group (CENM), Universidad del Valle, Santiago de Cali, Colombia

    R. Mejía de Gutierrez & J. Mejía

Authors
  1. C. Varga
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. M. M. Alonso
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. R. Mejía de Gutierrez
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. J. Mejía
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. F. Puertas
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to F. Puertas.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Varga, C., Alonso, M.M., Mejía de Gutierrez, R. et al. Decalcification of alkali-activated slag pastes. Effect of the chemical composition of the slag. Mater Struct 48, 541–555 (2015). https://doi.org/10.1617/s11527-014-0422-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1617/s11527-014-0422-4

Keywords

Search

Navigation