Hostname: page-component-848d4c4894-nr4z6 Total loading time: 0 Render date: 2024-06-07T06:04:42.644Z Has data issue: false hasContentIssue false
  • English
  • Français

Sulphate Expansion of Lime-Stabilized Kaolinite: II. Reaction Products and Expansion

Published online by Cambridge University Press:  09 July 2018

S. Wild ,
M. R. Abdi  and
G. Leng-Ward
S. Wild
Affiliation:
University of Glamorgan, Department of Civil Engineering and Building, Pontypridd, Mid Glamorgan CF37 1DL
M. R. Abdi
Affiliation:
University of Glamorgan, Department of Civil Engineering and Building, Pontypridd, Mid Glamorgan CF37 1DL
G. Leng-Ward
Affiliation:
University of Warwick, Department of Physics, Coventry CV4 7AL UK
Get access Rights & Permissions [Opens in a new window]

Abstract

The results of detailed analyses of the samples discussed in part I are reported. The chemical, morphological and microstructural changes which occurred during moist curing and soaking have been determined using thermal analysis, X-ray powder diffraction analysis, and scanning and transmission electron microscopy combined with EDAX. The analytical results together with the physical observations have shown that the period of volume instability and swelling coincides with the period of gypsum consumption and ettringite formation. However, swelling is not caused by growth of crystalline ettringite but is the result of water absorption. An osmotic mechanism is proposed in which concentration gradients are generated within a surface colloidal layer on the clay particles. Ettringite rods nucleate and grow within this layer and C-A-S-H gel is produced in the areas between the rods. This results in concentration gradients at the clay particle surfaces which provide the driving force for osmosis. The implications of these findings are discussed in relation to lime- stabilization of soils.

Type
Research Article
Information
Clay Minerals , Volume 28 , Issue 4 , December 1993 , pp. 569 - 583
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abdi, M.R. (1992) Effect of calcium sulphate on lime-stabilised kaolinite. PhD thesis, Polytechnic of Wales, UK.Google Scholar
Abdi, M.R. & Wild, S. (1993) Sulphate expansion of lime-stabilised kaolinite: Part I. Physical characteristics. Clay Miner. 28, 555–567.CrossRefGoogle Scholar
De Silva, P.S. & Glasser, F.P. (1990) Hydration of cements based on metakaolin; thermochemistry. Adv. Cem. Res. 3, 167–177.Google Scholar
Diamond, S., White, J.L. & Dolch, W.L. (1964) Transformation of clay minerals by calcium hydroxide attack. Clays Clay Miner. 12, 359–379.Google Scholar
Eades, J.L. & Grim, R.E. (1960) Reaction of hydrated lime with pure clay minerals in soil stabilisation. Highway Res. Board Bull. 262, 51–63.Google Scholar
Giergiezny, Z. & Weryuska, A. (1989) Influence of fineness of fly ashes on their hydration activity. Proc. 3rd Int. Conf. Fly Ash, Silica Fume, Slag and Natural Pozzolanas 1, 97–115.Google Scholar
Groves, G.W. (1983) TEM studies of cement clinker compounds, their hydration and strong cement pastes. Technology in the 1990s: Development in Hydraulic Cements. Phil. Trans. Roy. Soc. London. Series A, 310 (No. 11511), 79–83.Google Scholar
Hampson, C.J. & Bailey, J.E. (1983) The microstructure of the hydration products of tri-calcium aluminate in the presence of gypsum. J. Mat. Sci. 18, 402–410.Google Scholar
Hunter, D. (1988) Lime-induced heave in sulphate bearing clay soils. ASCE J. Geot. Eng. 114, 150–167.Google Scholar
Kuzel, H.J. (1976) Crystallographic data and thermal decomposition of synthetic hydrate 2CaO.Al2O3.SiO2.8H2O. Neues Jb. Min. Mon. 7, 319–325.Google Scholar
Lukas, W. (1976) Substitution of Si in the lattice of ettringite. Cem. Cone. Res. 6, 225–234.Google Scholar
Menetrier, D., Jawed, I. & Skalny, J. (1980) Effect of gypsum on C3S hydration. Cem. Cone. Res. 10, 697–701.Google Scholar
Mitchell, J.K. (1986) Delayed failure of lime-stabilised pavement bases. J. Geot. Eng. 112, 274–279.Google Scholar
Negro, A. & Bachiorrini, A. (1982) Expansion associated with ettringite formation at different temperatures. Cem. Cone. Res. 12, 677–684.Google Scholar
Wild, S., Hadi, M. & Leng-Ward, G. (1990) The influence of gypsum content on microstructural development, strength and expansion in cured PFA-lime mixes. Adv. Cem. Res. 12, 153–166.Google Scholar