Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-25T17:43:33.407Z Has data issue: false hasContentIssue false

Micromorphology and Mineralogy of Fly Ash and Lime Stabilized Bentonite

Published online by Cambridge University Press:  21 February 2011

Ray E. Ferrell Jr.
Affiliation:
Basin Research Institute, Louisiana State University, Baton Rouge, LA 70803
Ara Arman
Affiliation:
Louisiana Transportation Research Center, Baton Rouge, LA 70803
Gokhan Baykal
Affiliation:
Department of Civil Engineering, Louisiana State University, Baton Rouge, LA 70803
Get access

Abstract

Compacted fly ash, lime, bentonite and water mixtures were cured at 23° and 50°C, for 1, 28, 90 and 180 days. Cementitious products and microstructure were observed by scanning electron microscopy, energy dispersive x-ray spectrometry and x-ray diffractometry. Unconfined compressive strength changes are correlated to the formation of new mineral phases. For bentonite-limefly ash mixtures, strength increased from 1050 kPa (I day) to 2,300 kPa (90 days) and then slightly increased to 2,400 kPa after 180 days at ∼ 230C. Ettringite is the most abundant mineral associated with the increased compressive strength.

New minerals identified in the 23°C mixtures include calcium silicate hydrate - Type 1, afwillite and ettringite. Acicular crystals of these and other minerals were formed by the hydration of lime and fly ash in the montmorillonitic clay. The cementitious phases create a rigid framework joining spheres and clay aggregates. Continued reaction dissolves some of the spheres and slightly reduces the rigidity of the cured samples.

Type
Research Article
Copyright
Copyright © Materials Research Society 1988

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

REFERENCES

1. Winterkorn, H.F., Soil Stabilization, Foundation Enpineerins Handbook, p. 312.Google Scholar
2. Keshawarz, M.S., and Laguros, J.G., in, Fly Ash and Coal Conversion By-Products: Characterization. Utilization and Disposal II, edited by McCarthy, G.J., Glasser, F.P., and Roy, D.M., (Mat. Res. Soc. Symp. Proc. Vol.65, Pittsburgh PA 1986) pp. 3746.Google Scholar
3. Mills, R.H., in, Fly Ash and Coal Conversion By-Products: Characterization. Utilization and Disposal II, edited by McCarthy, G.J., Glasser, F.P., and Roy, D.M., (Mat. Res. Soc. Symp. Proc. Vol.65, Pittsburgh PA 1986), pp. 207217.Google Scholar
4. Luke, K., and Glasser, F.P., in, Fly Ash and Coal Conversion By-Products: Characterization. Utilization and Disposal II, edited by McCarthy, G.J., Glasser, F.P., and Roy, D.M., (Mat. Res. Soc. Symp. Proc. Vol.65, Pittsburgh PA 1986), pp. 173180.Google Scholar
5. Glasser, F.P., Diamond, S., and Roy, D.M., in, Fly Ash and Coal Conversion By-Products: Characterization. Utilization and Disposal III, edited by McCarthy, G.J., Glasser, F.P., Roy, D.M., and Diamond, S., (Mat. Res. Soc. Symp. Proc. Vol. 86, Pittsburgh, PA 1987), pp. 139158.Google Scholar
6. Stevenson, R.J., and Huber, T.P., Fly Ash and Coal Conversion By-Products: Characterization. Utilization and Disposal III, edited by McCarthy, G.J., Glasser, F.P., Roy, D.M., and Diamond, S., (Mat. Res. Soc. Symp. Proc. Vol. 86, Pittsburgh, PA 1987), pp. 99108.Google Scholar
7. McCarthy, G.J., Powder Diffraction, 1, 5055 (1986).Google Scholar
8. Diamond, S., “Cement Paste Microstructure - An Overview at Several Levels, in Proceedings of a Conference held at the University of Sheffield, April 8–9, 1976.Google Scholar