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Similarities and Differences in Shale, Aggregate Mixes and Concrete Containing Fly Ash

Published online by Cambridge University Press:  21 February 2011

Petros E. Zenieris
Affiliation:
Standard Testing and Engineering Company, Oklahoma City, Oklahoma 73105
Joakim G. Laguros
Affiliation:
School of Civil Engineering and Environmental Science, The University of Oklahoma, Norman, Oklahoma 73019, U.S.A.
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Abstract

Fly ash technology has been very effective in providing stability in roadway base courses composed either of shale or aggregate materials, and also in partly replacing Portland cement in concrete. X-ray diffractometry and scanning electron microscopy observations indicate that there are certain similarities among these three types of mixes concerning the hydration process; on the other hand, there is evidence of distinct differences in the hydration products which are found to act either as a filler, a chemical agent, or both. Fly ash suppresses the intensity of the clay minerals in shale, speeds up the hydration process in concrete and acts partly as a filler in aggregate mixes. The net practical result is strength development which varies not only in terms of the maximum level attained, but also in regard to its rate. The conversion of ettringite to monosulfoaluminate proceeds at a rate which is considered high in concrete, moderate in aggregate mixes, and moderate to low in shale. X-ray diffraction analyses help to identify other dissimilarities in the minerals produced. The modification which takes place in the fabric and the matrix of the mixes is morphologically the same; in contrast, the growth of crystallites at the “particle”/fly ash interface is explicitly different. Preliminary quantification of matrix changes resulting from new hydration products is also explored.

Type
Research Article
Copyright
Copyright © Materials Research Society 1989

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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, Mat. Res. Soc. Symp. Proc. Vol 65, edited by McCarthy, G.J., Glasser, F.P. and Roy, D.M. (Materials Research Society, Pittsburgh, 1986) pp. 3746.Google Scholar
2. Laguros, J.G. and Medhani, R. in Proc. 2nd Int. Conf. on Ash Technology (CEGB, London, 1984) pp.500504.Google Scholar
3. Laguros, J.G. and Baker, M.D. in Fly Ash and Coal Conversion By-Products: Characterization. Utilization and Disposal I, Mat. Res. Soc. Symp. Proc. Vol 43, edited by McCarthy, G.J. and Lauf, R. (Materials Research Society, Pittsburgh, 1985) pp. 7383.Google Scholar
4. Baker, M.D., Fly Ash Concrete: A Study of the Reaction Products Using XRD and SEM, M.S. Thesis, unpublished, The University of Oklahoma, Norman, OK (1983).Google Scholar
5. Laguros, J.G. and Zenieris, P. in Fly Ash and Coal Conversion By-Products: Characterization. Utilization and Disposal IV, Mat. Res. Soc. Symp. Proc. Vol 113, edited by McCarthy, G.J., Glasser, F.P., Roy, D.M. and Hemmings, R.T. (Materials Research Society, Pittsburgh, 1988) pp. 231240.Google Scholar
6. Zenieris, P., Feasibility of Using Fly Ash as a Binder in Coarse and Fine Aggregates for Bases, M.S. Thesis, unpublished, The University of Oklahoma, Norman, OK (1988).CrossRefGoogle Scholar
7. McClune, W.F., Editor-in-Chief, Powder Diffraction File (JCPDS - International Centre for Diffraction Data, Swarthmore, PA).Google Scholar
8. Fly Ash Design Manual for Road and Site Applications, Vol I, EPRI RP 2422-2 (Electric Power Research Institute, Palo Alto, 1986).Google Scholar
9. Lea, F., The Chemistry of Cement and Concrete, 3rd ed. (Chemical Publishing Co., New York, N.Y., 1970).Google Scholar
10. Diamond, S. and Lopez-Flores, L. in Effects of Fly Ash Incorporation in Cement and Concrete, edited by Diamond, S. (Mat. Res. Soc. Proc., University Park, PA, 1981) pp. 112123.Google Scholar
11. Gosh, S.N., Advances in Cement Technology. Critical Reviews and Case Studies on Manufacturing. Ouality Control. Optimization and Use (Pergamon Press, New York, 1983).Google Scholar
12. Grutzeck, M.W., Roy, D.M. and Sheetz, B.N. in Effects of Fly Ash Incorporation in Cement and Concrete, edited by Diamond, S. (Mat. Res. Soc. Proc., University Park, PA, 1981) pp. 92102.Google Scholar