Pessimum effect of externally applied chlorides on expansion due to delayed ettringite formation: Proposed mechanism
- Department of Civil Engineering, University of Toronto, 35 St. George Str, Toronto, ON, M5S 1A4 (Canada)
- Department of Civil Engineering, University of New Brunswick, P.O. Box 4400, Fredericton, N.B., E3B 5A3 (Canada)
Mortars and concretes were subjected to a heat treatment cycle consisting of a pre-set period of 4 h at 23 deg. C followed by accelerated curing at 95 deg. C prior to storage at room temperature in water or limewater, 0.5 M, 2.8 M sodium chloride solutions. It was found that the specimens stored in 0.5 M sodium chloride solution gave a much greater expansion than those stored in limewater or 2.8 M sodium chloride solution. This pessimum influence of chlorides on expansion due to delayed ettringite formation deviates from the commonly held view that chlorides mitigate sulphate attack in concretes. The mechanism of the pessimum effect of chlorides on expansion due to delayed ettringite formation, and the final products of the associated phase transformations have been proposed. X-ray diffraction and differential thermal analysis techniques were used to follow phase transformations.
- OSTI ID:
- 20793283
- Journal Information:
- Cement and Concrete Research, Vol. 36, Issue 4; Other Information: DOI: 10.1016/j.cemconres.2005.11.020; PII: S0008-8846(05)00305-4; Copyright (c) 2005 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
- Country of Publication:
- United States
- Language:
- English
Similar Records
Diagnosing delayed ettringite formation in concrete structures
Ettringite-Related Dimensional Stability of CO2-Cured Portland Cement Mortars