TY - JOUR
T1 - Effects of curing temperature and NaOH addition on hydration and strength development of clinker-free CKD-fly ash binders
AU - Wang, Kejin
AU - Shah, Surendra P.
AU - Mishulovich, Alexander
N1 - Funding Information:
The authors would like to acknowledge the Cement for Advanced Cement Based Materials (ACBM) and the National Science Foundation (NSF) for providing funding for the present research under Research Grant Number (CMS-0086819). All tests were performed at Iowa State University (ISU). The authors would like to thank the Materials Analysis and Research Laboratory at ISU for providing facilities and assistance on TGA and XRD tests and Lafarge, Cement Group/U.S. Region, for providing raw materials and information.
PY - 2004/2
Y1 - 2004/2
N2 - 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 °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 °C), addition of a small amount of NaOH (2%) may increase CKD-FA binder strength; while at a high curing temperature (50 °C), addition of NaOH (2%) may reduce the binder strength.
AB - 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 °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 °C), addition of a small amount of NaOH (2%) may increase CKD-FA binder strength; while at a high curing temperature (50 °C), addition of NaOH (2%) may reduce the binder strength.
KW - Cement kiln dust
KW - Elevated curing temperature
KW - Fly ash
KW - NaOH addition
KW - Thermal analysis
KW - X-ray diffraction
KW - XRD
UR - http://www.scopus.com/inward/record.url?scp=0742272523&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0742272523&partnerID=8YFLogxK
U2 - 10.1016/j.cemconres.2003.08.003
DO - 10.1016/j.cemconres.2003.08.003
M3 - Article
AN - SCOPUS:0742272523
VL - 34
SP - 299
EP - 309
JO - Cement and Concrete Research
JF - Cement and Concrete Research
SN - 0008-8846
IS - 2
ER -