Effects of curing temperature and NaOH addition on hydration and strength development of clinker-free CKD-fly ash binders
Effects of curing temperature and NaOH addition on hydration and strength development of cement kiln dust (CKD)-fly ash (FA) binders were investigated. Pastes made with 50% CKD and 50% FA, having 0, 2, and 5% NaOH addition, and cured at temperatures of 24, 38, and 50 deg. C were evaluated. The hydration products of the binders were examined by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) tests. The results indicate that the major crystalline hydration product of the CKD-FA binders is ettringite, and the ettringite is stable in the CKD-FA system at age over 100 days. Curing at elevated temperature is more effective for CKD-FA binder strength improvement than NaOH addition, the later often depressing ettringite formation in a CKD-FA system. At a proper curing temperature (38 deg. C), addition of a small amount of NaOH (2%) may increase CKD-FA binder strength; while at a high curing temperature (50 deg. C), addition of NaOH (2%) may reduce the binder strength.
- OSTI ID:
- 20658338
- Journal Information:
- Cement and Concrete Research, Vol. 34, Issue 2; Other Information: DOI: 10.1016/j.cemconres.2003.08.003; PII: S0008884603002813; Copyright (c) 2003 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
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