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Fly Ash As A Binder in Aggregate Base Courses

Published online by Cambridge University Press:  21 February 2011

Petros Zenieris  and
Joakim G. Laguros
Petros Zenieris
Affiliation:
Standard Testing and Engineering Co., Oklahoma City, Oklahoma 73105
Joakim G. Laguros
Affiliation:
School of Civil Engineering and Environmental Science, The University of Oklahoma, Norman, Oklahoma 73019 USA
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Abstract

The benefit of adding up to 35 wt% Class C high calcium fly ash to various types of fine and coarse aggregate pavement mixes is described and quantified. The mixes, which were compacted to maximum dry density at optimum moisture content, had variable compressive strengths during the first 28 days of curing; after that they assumed a relatively uniform pattern of strength gain reaching values as high as 11 MPa (1600 psi). Mixes containing 15% fly ash gave unacceptably low strengths. XRD measurements indicated massive formation of ettringite, transforming to monosulfoaluminate and the poorly crystallized hydrated phases of C-A-H, C-A-S-H and C-S-H. This transformation helps explain the gain in strength of the mixes with extended curing. SEM observations depicted progressive packing and densification of the skeletal matrix as the hexagonal phases and C-S-H gained higher crystallinity and formed aggregated masses. Furthermore, these observations suggest that fly ash acts predominantly as a chemical binder and partly as a filler in the aggregate mixes tested.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 113: Symposium Q – Fly Ash and Coal Conversion By-Products IV , 1987 , 231
Copyright
Copyright © Materials Research Society 1988

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References

REFERENCES

1. Laguros, J.G. and Keshawarz, M.S., 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 (Materials Research Society, Pittsburgh, 1986) pp. 37–46.Google Scholar
2. Barenberg, E.J., Lime-Fly Ash Aggregate Mixtures, Bureau of Mines Information Circular No. 8348, (U.S. Department of Interior, Washington, D.C., 1974).Google Scholar
3. Electric Power Research Institute, Fly Ash Design Manual for Road and Site Applications, Vol.1, Project No. 2422–2, 1986.Google Scholar
4. Meyers, J.F., Pichumain, R. and Kapples, B.S., Fly Ash as a Construction Material for Highways, FHWA-IP-76-76, (Federal Highway Administration, Washington, D.C., June 1976).Google Scholar
5. Barenberg, E.J., Cement Fly Ash Mixes for Pavements, 7th Int. Ash Utilization, Symp. and Exp. Proc. (National Ash Association, 1985) pp. 57–66.Google Scholar
6. Grutzeck, M.W., Roy, D.M. and Scheetz, B.E., in Effects of Fly Ash Incorporation in Cement and Concrete, edited by Diamond, S., Mat. Res. Soc. Symp. N. Proc. (Materials Research Society, Pittsburgh, 1981) pp. 92–101.Google Scholar
7. Novotny, S.J., Fly Ash/Lime/Aggregate Roadway Base Course for Keystone Steam Generating Station Ash Haul Road, 7th Int. Ash Utilization Symp. and Exp. Proc., (National Ash Association 1985) pp. 859–867.Google Scholar
8. Townsend, F.C. and Donaghe, R.T., Investigation of Accelerated Curing of Soil-Lime and Lime- Fly Ash-Aggregate Mixtures, Tech. Rpt, (U.S. Army Engr. Waterways Exp. Sta., Vicksburg, Miss., 1976).Google Scholar
9. Transportation Research Board, Lime-Fly Ash Stabilized Base and Subbases, Technical Report PB-259–432 (U.S. Department of Commerce, Washington, D.C., October 1976).Google Scholar
10. McClune, W.F., Editor-in-Chief, Powder Diffraction File (JCPDS-International Centre for Diffraction Data, Swarthmore, PA).Google Scholar