TY - JOUR
T1 - A Raman spectroscopic study of the evolution of sulfates and hydroxides in cement-fly ash pastes
AU - Garg, Nishant
AU - Wang, Kejin
AU - Martin, Steve W.
N1 - Funding Information:
The authors appreciate the sponsorship of the Oak Ridge Associated Universities (ORAU) - Tennessee Valley Authority (TVA) (Grant No. 7-22976 ). Special thanks are given to Dr. Randilynn Christensen for her support and inputs in the Raman spectroscopy tests, and to Dr. Scott Schlorholtz for providing guidance and insightful comments on other experiments. Authors are grateful to an anonymous reviewer for greatly helping in improving the manuscript.
Copyright:
Copyright 2013 Elsevier B.V., All rights reserved.
PY - 2013
Y1 - 2013
N2 - Raman spectroscopy has been employed to study the evolution of sulfo-aluminate and hydroxyl phases in pastes made with ordinary Portland cement (OPC) and fly ash (FA). Three fly ashes with different CaO contents were used as a cement replacement at the level of 0 and 50% by weight. The pastes were analyzed at 0, 0.2, 2, 4, 8, 12, 16, 20, 24, 48, 72 h, and 7, 14, 21, 28, and 56 days after mixing. The wavenumber ranges used for Raman spectroscopic analysis are 950-1050 cm- 1 for evolution of sulfates and 3600-3700 cm - 1 for evolution of hydroxides. Gradual disappearances of gypsum in parallel with the formation of ettringite (AFt) are clearly observed in most paste mixes. Evolution of hydroxides showed the gradual spatial growth of portlandite. In addition to the potential benefits, the limitations of using Raman spectroscopy in study of cement-based materials are also noted in this paper.
AB - Raman spectroscopy has been employed to study the evolution of sulfo-aluminate and hydroxyl phases in pastes made with ordinary Portland cement (OPC) and fly ash (FA). Three fly ashes with different CaO contents were used as a cement replacement at the level of 0 and 50% by weight. The pastes were analyzed at 0, 0.2, 2, 4, 8, 12, 16, 20, 24, 48, 72 h, and 7, 14, 21, 28, and 56 days after mixing. The wavenumber ranges used for Raman spectroscopic analysis are 950-1050 cm- 1 for evolution of sulfates and 3600-3700 cm - 1 for evolution of hydroxides. Gradual disappearances of gypsum in parallel with the formation of ettringite (AFt) are clearly observed in most paste mixes. Evolution of hydroxides showed the gradual spatial growth of portlandite. In addition to the potential benefits, the limitations of using Raman spectroscopy in study of cement-based materials are also noted in this paper.
KW - Ca(OH)2 (D)
KW - Cement (D)
KW - Fly ash (D)
KW - Raman spectroscopy (nominated)
KW - Sulfo-aluminate (D)
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U2 - 10.1016/j.cemconres.2013.06.009
DO - 10.1016/j.cemconres.2013.06.009
M3 - Article
AN - SCOPUS:84880019134
SN - 0008-8846
VL - 53
SP - 91
EP - 103
JO - Cement and Concrete Research
JF - Cement and Concrete Research
ER -