Expansion of Alite Paste Caused by Gypsum Formation during Sulfate Attack
Publication: Journal of Materials in Civil Engineering
Volume 12, Issue 1
Abstract
This paper introduces a study carried out to investigate sulfate attack caused by gypsum formation. The aim, specifically, was to study whether gypsum formation can be a factor leading to expansion in concrete exposed to solutions containing sulfate ions. It was found from the laboratory study that alite paste specimens (0.48 water-to-alite ratio) expanded and cracked significantly in 5% Na2SO4 solution after a “dormant” period of about 1 year. X-ray diffraction confirmed that gypsum was the main product—ettringite does not form in the system, because of the lack of aluminate. The detailed study of the mechanism for expansion and cracking is continuing. These findings confirm the long-term understanding that sulfate attack mechanism is a complicated process. A highlight of the study, therefore, reveals that expansion and cracking of portland cement concrete may not be attributed solely to ettringite formation. Gypsum formation may be a cause leading to expansion and subsequent cracking. More research is needed in this area.
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References
1.
Bonen, D., and Cohen, M. D. (1992). “Magnesium sulfate attack on portland cement paste—I. Microstructural analysis.” Cement Concrete Res., 22, 169–180.
2.
Bonen, D., and Sarkar, S. L. ( 1993). “Replacement of portlandite by gypsum in the interfacial zone and cracking related to crystallization pressure.” Ceramics Transactions, American Ceramics Society, Westerville, Ohio, Vol. 37, 49–59.
3.
Cohen, M. D., and Mather, B. (1991). “Sulfate attack on concrete—research needs.” ACI Mater. J., 88(1), 62–69.
4.
Gonzalez, M. A., and Irassar, E. F. (1997). “Ettringite formation in low C3A portland cement exposed to sodium sulfate solution.” Cement Concrete Res., 27(7), 1061–1072.
5.
Hansen, W. C. (1966). “Attack on portland cement concrete by alkali soil and water—a critical review.” Hwy. Res. Rec., No. 113, 1–32.
6.
Mather, B. (1996). “Discussion of `The process of sulfate attack on cement mortars.”' Adv. Cement Based Mat., 5, 109–110.
7.
Mehta, P. K. ( 1992). “Sulfate attack on concrete—a critical review.” Materials science of concrete III, American Ceramics Society, Westerville, Ohio, 105–130.
8.
Ping, X., and Beaudoin, J. J. (1992). “Mechanism of sulfate expansion I. Thermodynamic principles of crystallization pressure.” Cement Concrete Res., 22(4), 631–640.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 12 • Issue 1 • February 2000
Pages: 24 - 25
History
Received: Sep 7, 1999
Published online: Feb 1, 2000
Published in print: Feb 2000
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