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Sulphate Durability of Plain and Fly Ash Mortars

Published online by Cambridge University Press:  21 February 2011

R. L. Day
Affiliation:
Department of Civil Engineering, University of Calgary, Alberta, T2N IN4 Canada
M. A. Ward
Affiliation:
Department of Civil Engineering, University of Calgary, Alberta, T2N IN4 Canada
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Abstract

Sulphate expansion and strength tests were performed on mortars containing equal proportions of Type 10 (ASTM Type I) Portland cement and fly ash as the cementitious material. Two intermediate-Ca subbituminous ashes, one high-Ca subbituminous ash and one bituminous ash were tested. Control mortars manufactured with Types 10 and Type 50 (Type V ASTM) cements and one mortar containing 50% replacement of cement with limestone powder were also examined. The period and temperature of curing prior to sulphate exposure and the concentration and pH of the attacking solutions were other test parameters. Results indicate that the two intermediate-Ca subbituminous ashes from Alberta Canada, combined with Type 10 cement produce mortars that show excellent long-term strength, acceptable short term strength, and are highly resistant to attack by aggressive sulphate solutions. In some cases durability of these mortars was better than the control mortar made with Type 50 cement. On the other hand, mortar made using the high-Ca ash showed very high susceptibility to sulphate attack; at the same time, mortars made with this ash showed good strength development. Qualitative x-ray diffraction analysis indicates the presence of more lime, magnesium and iron bearing crystalline compounds in the high-Ca ash than in the Alberta ashes. These appear to be responsible for the poor performance in sulphate environments.

Type
Research Article
Copyright
Copyright © Materials Research Society 1988

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References

REFERENCES

1. Price, G.C. and Peterson, R., in Performance of Concrete. Resistance of Concrete to Sulphate and Other Environmental Conditions, edited by Swenson, E.G. (University of Toronto Press, Toronto, 1968), p. 93.Google Scholar
2. Gonnerman, H.F., Lerch, W., ASTM STP #127, 1 (1951)Google Scholar
3. The Concrete Society, Changes in Cement Properties and Their Effects on Concrete, Report of a Concrete Society Working Party, Sept. (1984).Google Scholar
4. Helmuth, R., Fly Ash in Cement and Concrete, (Portland Cement Association, Skokie, Illinois, 1987), p. 203.Google Scholar
5. Dunstan, E.R. Jr., Cement, Concrete and Aggregates, 2, 20 (1980).Google Scholar
6. Mehta, P.K., J. Amer. Concr. Inst., 83, 994 (1986)Google Scholar
7. McCarthy, G.J., Swanson, K.D., Keller, L.P., Blatter, W.C., Cem. Concr. Res., 14, 471 (1984).Google Scholar
8. Manz, O.E., McCarthy, G.J., J. Amer. Concr. Inst., to be published (1988).Google Scholar
9. Hartmann, C., Mangotich, E., in Concrete Durability, edited by Scanlon, J.M. (Amer. Concr. Inst., SP-100, 2, Detroit, 1987) pp. 21352151.Google Scholar
10. Day, R.L., Joshi, R.C., Intnl. Seminar on Some Aspects of Admixtures and Industrial By-Products on the Durability of Concrete, Goteborg, Sweden, May (1986).Google Scholar
11. Perry, C., Day, R.L., Joshi, R.C., Langan, B.W., Gillott, J.E., in Proc. 7th Intnl. Conf. on Alkali-Aeerepate Reactions, Ottawa, 1987, pp. 9394.Google Scholar
12. Mehta, P.K., Cem. Concr. Res., 13, p. 401 (1983).Google Scholar
13. Diamond, S., Cem. Concr. Res., 13, p. 459 (1983).Google Scholar