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Electrochemical Stability of Embedded Steel and Toxic Elements in Fly Ash/Cement Beds

Published online by Cambridge University Press:  25 February 2011

R. I. A. Malek  and
D. M. Roy
R. I. A. Malek
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802 USA
D. M. Roy
Affiliation:
Also affiliated with the Department of Materials Science and Engineering.
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Abstract

The electrochemical stability in fly ash/cement beds is of major concern to the durability of construction metals (iron or steel) embedded in the matrix as well as the stabilization (fixation) of toxic elements. The electrochemical stabilities were evaluated by measuring the redox potential as a function of both time and leach solution. For simulating the field conditions, the measurements were made on leachates of a prepared solution simulating rain composition in the area of application and results were contrasted to those obtained on leachates of standard deionized water. Two leaching techniques were used: the standard EPA-EP test; a test developed at MRL/PSU for simulating field conditions in which leaching fluids are pumped up a fly ash/cement column. The redox potentials (based on hydrogen scale), Eh's, were plotted vs. pH of the leachates and the regions of stability of various construction materials and toxic elements were predicted. Tafel plots were also constructed for iron in contact with different leachates, and its corrosion rate was estimated.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 86: Symposium N – Fly Ash and Coal Conversion By-Products III , 1986 , 59
Copyright
Copyright © Materials Research Society 1987

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References

REFERENCES

1. Malek, R.I.A., Licastro, P.H., and Roy, D.M., 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. 269–284.Google Scholar
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