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Lime stabilisation of clay soils

  • F. G. Bell
Article

Abstract

Clay soil can be stabilised by the addition of a small percentage, by weight, of lime, that is, it enhances many of the engineering properties of the soil. This produces an improved construction material and so the technique has been used for many construction purposes, notably in highway, railroad and airport construction to improve subgrades and sub-bases. Generally the amount of lime needed to modify a clay soil varies from 1 to 3 per cent, whilst that required for cementation varies from 2 to 8 per cent.

When lime is added to clay soils, calcium ions are combined initially with or adsorbed by clay minerals which leads to an improvement in soil workability, that is, to an increase in the plastic limit of the clay and generally to a decrease in its liquid limit. The optimum lime additive for maximum increase of the plastic limit of the soil is referred to as the lime fixation point Lime added in excess of the fixation point is utilised in the cementation process and gives rise to an increase in soil strength. The increase in strength has been attributed to the formation of poorly ordered reaction products which surround the clay minerals.

Keywords

Lime Clay Mineral Kaolinite Unconfined Compressive Strength Clay Soil 

Stabilisation de sols argileux à la chaux

Résumé

L'argile peut étre traitée en ajoutant une faible teneur de chaux, en poids, ce qui améliore un grand nombre de propriétés géotechniques du sol. Par exemple ce traitement permet d'améliorer certains matériaux de construction, tels que les granulats de couches de forme ou de fondation pour les routes, les chemins de fer ou les pistes d'aérodromes. Le pourcentage d'ajout varie de 1 à 3% pour modifier un sol argileux, tandis qu'il faut entre 2 et 8% pour obtenir une cimentation.

Quand la chaux est ajoutée aux sols argileux, les ions calcium ou bien se combinent avec les minéraux argileux ou bien sont adsorbés par ces derniers, ce qui provoque une amélioration de la maniabilité, c'est-à-dire une augmentation de la limite de plasticité de l'argile et généralement une diminution de la limite de liquidité. Le pourcentage optimum d'ajout de chaux pour l'obtention de l'accorissement maximum de la limite de plasticité du sol est appelé ≪seuil de fixation de la chaux≫. Si l'on ajoute de la chaux au-delà de ce seuil elle est utilisée par le processus de cimentation, et conduit à une augmentation de la résistance du sol. Cette augmentation de résistance a été attribuée à la formation de produits de réaction mal cristallisés, qui entourent les minéraux argileux. granulats.

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References

  1. AL-RAWI N.M., 1981: The effect of curing temperature on lime stabilisation.Proc. 2nd Aust Conf on Engineering Materials, Sydney, 611–662.Google Scholar
  2. AL-RAWI N.M. and AWAD A.A.A., 1981: Permeability of lime stabilised soils. Proc. ASCE, Trans Engng Div., 107, TE1, 25–35.Google Scholar
  3. BELL F.G., 1988: Stabilisation and treatment of clay soils with lime-some applications. Ground Engineering, 21, No. 2, 22–30.Google Scholar
  4. BELL, F.G. and TYRER M.J., 1987: Lime stabilization and clay mineralogy.Proc. Conf. Foundations and Tunnels '87, vol. 2, Engineering Technics Press, Edinburgh, 1–7.Google Scholar
  5. BHASIN N.K. DHAWAN P.K. and MEHTA H.S., 1978: Lime requirement in soil stabilisation.Highway Research Board, Bulletin No. 7, Washington DC, 15–26.Google Scholar
  6. BRANDL, H., 1981: Alteration of soil parameters by stabilisation with lime.Proc. 10th Int. Conf. Soil Mech. Found. Engng. Stockholm, vol. 3, 587–594.Google Scholar
  7. CROFT J.B., 1964: The processes involved in the lime stabilisation of clay soils.Proc. Aust. Road Research Board, vol. 2, Part 2, 1169–1203.Google Scholar
  8. DAVIDSON D.T., and HANDY R.L., 1960: Lime and lime-pozzolan. In:Highway Engineering Handbook. Ed by Woods K.B., McGraw Hill, New York, 23–98.Google Scholar
  9. HILT G.H. and DAVIDSON D.T. 1960: Lime fixation of clayey soils.Highway Research Board, Bulletin 262, Washington DC, 20–32.Google Scholar
  10. HOLM G., 1979:Lime column stabilisation—experience concerning strangth and deformation properties. Vag-och Vottenbyggaren, 25. No. 7-8, 45–49.Google Scholar
  11. INGLES O.G. and METCALF J.B., 1972: Soil Stabilisation. Butterworths, Sydney.Google Scholar
  12. LAGUROS J.G., DAVIDSON D.T., HANDY R.L. and CHU T.Y., 1956:Evaluation of lime stabilisation of loess. Proc. ASTM, 56. 1301–1319.Google Scholar
  13. MARKS B.D. and HALIBURTON T.A., 1972: Acceleration of lime-clay reactions with salt.Proc. ASCE Jour. Soil Mech. Found Div., 98, SM4, 327–339.Google Scholar
  14. MATEOUS M., 1964:Soil-lime research at Iowa State University. Proc. ASCE,Jour. Soil Mech. Found. Div., 90, SM2, 127–153.Google Scholar
  15. MITCHELL J.K. and HOOPER D.R., 1961: Influence of time between mixing and compaction on properties of lime stabilised expansive clay.Highway Research Board, Bulletin 304, Washington DC, 14–31.Google Scholar
  16. SABRY M.M.A. and PARCHER J.V., 1979: Engineering properties of soil-lime mixes.Proc. ASCE, Jour. Trans. Engng, 107, TE1, 25–35.Google Scholar
  17. THOMPSON M.R., 1968: Lime stabilisation of soils for highway purposes—final report. Illinois Highway Engineering Series, No. 25.Google Scholar
  18. THOMPSON M.R. and HARTY, J.R., 1973: Lime reactivity of tropical and subtropical soils.Highway Res. Record No. 442, Highway Research Board, Washington DC, 105–112.Google Scholar

Copyright information

© International Association of Engineering Geology 1989

Authors and Affiliations

  • F. G. Bell
    • 1
  1. 1.NottinghamEngland

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