The effect of water and gypsum content on strätlingite formation in calcium sulfoaluminate-belite cement pastes
Document Type
Article
Publication Date
3-30-2018
Abstract
The main objective of this study was to investigate the phase and strength development of calcium sulfoaluminate-belite (CSAB) cement pastes with different amounts of gypsum and water. Thermodynamic modeling and a series of experiments including X-ray diffraction (XRD), thermogravimetric analysis, isothermal calorimetry, and compressive strength tests were performed. Decreasing the mixing water increased the strength of CSAB pastes, but decreased the degree of hydration. Interpretation of the early age XRD results and thermodynamic modeling suggested the formation of a meta-stable phase from the hydration of belite, possibly C-(A)-S-H, which transformed into strätlingite at later ages only in the samples with high water content, likely due to easier diffusion of ions at higher w/c. Furthermore, the XRD results and thermodynamic modeling confirmed that the amount of gypsum controls the hydration of ye'elimite as well as belite in the CSAB cements.
Publication Title
Construction and Building Materials
Volume
166
First Page
712
Last Page
722
Digital Object Identifier (DOI)
10.1016/j.conbuildmat.2018.01.153
ISSN
09500618
Citation Information
Jeong, Hargis, C. W., Chun, S.-C., & Moon, J. (2018). The effect of water and gypsum content on strätlingite formation in calcium sulfoaluminate-belite cement pastes. Construction & Building Materials, 166, 712–722. https://doi.org/10.1016/j.conbuildmat.2018.01.153