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The Permeability of Chloride Ions in Fly Ash-Cement Pastes, Mortars and Concrete

Published online by Cambridge University Press:  21 February 2011

R. I. A. Malek
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802
D. M. Roy
Affiliation:
Materials Research Laboratory, The Pennsylvania State University, University Park, PA 16802
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Abstract

Fly ash-cement pastes are known to develop fine pore structures that may retard the transport of ionic species. The rapid chloride permeability technique for studying the Cl ion diffusion in hydrated fly ash/cement pastes, mortars and concrete was used. The technique applies an electrical potential across a cylindrical sample and measures the charge passed in a certain period of time. The results obtained on pastes and mortars cured for 28 days were reported previously and contrasted with those of neat cement pastes and mortars. The present paper reports more extensive studies made to examine the chloride permeabilities of pastes and mortars cured for up to 90 days. In addition, the effect of variable fly ash contents was examined. Concrete samples were included in the test scheme and the data were compared with pastes and mortars. Two important factors controlling the test results are discussed: first the mix design and curing conditions; second the experimental conditions during Cl permeability measurements. In the second factor, the amount and rate of heat build up and the chloride ion concentrations are compared with the current passed. In addition, measuring current versus resistivity are critically discussed in terms of the voltage-current varistic characteristics of cement matrices.

Type
Research Article
Copyright
Copyright © Materials Research Society 1988

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References

REFERENCES

1. Silsbee, M., Malek, R.I.A. and Roy, D.M., in Proceedines. 8th International Congress on the Chemistry of Cement, Brazil, V.IV, 263–269 (1986).Google Scholar
2. Page, C.L. and Vennesland, O., Mater. Struct. (Paris) 16 (91), 1925 (1983).Google Scholar
3. Diamond, S. and Lopez-Flores, F., Am. Cer. Soc. Communications, C-162- C-164 (1981).Google Scholar
4. Diamond, S., Cem. Concr. Res. 11, 383394 (1984).CrossRefGoogle Scholar
5. Kumar, A. and Roy, D.M., in Proceedings. 8th International Congress on the Chemistry of Cement, Brazil, V.5, 73–79 (1986).Google Scholar
6. Page, C.L., Short, N.R. and Tarras, A. El, Cem. Concr. Res. 11, 395406 (1981).Google Scholar
7. Roy, D.M., Kumar, A. and Rhodes, J.P., in Fly Ash. Silica Fume. Slag. and Natural Pozzolans in Concrete, Vol.2, ACI, SP-91, Ed. Malhotra, V.M., 14231444 (1986).Google Scholar
8. Page, C.L., Short, N.R. and Holden, W. R, Cem. Concr. Res. 1, 7986 (1986).Google Scholar
9. Uchikawa, H., Uchida, S. and Ogawa, K., Review, C.A.J., 56–59 (1984).Google Scholar
10. Roy, D.M., Malek, R.I.A., Rattanussorn, M. and Grutzeck, M.W., in Fly Ash and Coal Conversion By-Products, Mat. Res. Soc. Proc. Vol.65, edited by McCarthy, G.J., Glasser, F.P. and Roy, D.M. (Materials Research Society, Pittsburgh, PA, 1986) pp. 219226.Google Scholar
11. Malek, R.I.A., Roy, D.M. and Licastro, P.H., in Fly Ash and Coal Conversion By-Products, Mat. Res. Soc. Proc. Vol.86, edited by McCarthy, G.J., Glasser, F.P., Roy, D.M. and Diamond, S. (Materials Research Society, Pittsburgh, PA, 1987) pp. 239250.Google Scholar
12. Roy, D., Malek, R. and Licastro, P.H., in Concrete Durability, Katharine and Bryant Mather, International Conference, ACI SP-100 Vol. 11 (American Concrete Institute, Detroit, 1987) pp. 1459–75.Google Scholar