The effect of calcium chloride (CaCl 2 ) on tricalcium silicate (C 3 S) hydration was investigated by scanning transmission X‐ray microscopy (STXM) with Near Edge X‐ray Absorption Fine Structure (NEXAFS) spectra and 29 Si MAS NMR. STXM is demonstrated to be a powerful tool for studying the chemical composition of a cement‐based hydration system. The Ca L 3,2 ‐edge NEXAFS spectra obtained by examining C 3 S hydration in the presence of CaCl 2 showed that this accelerator does not change the coordination of calcium in the calcium silicate hydrate (C‐S‐H), which is the primary hydration product. O K‐edge NEXAFS is also very useful in distinguishing the chemical components in hydrated C 3 S. Based on the Ca L 3,2 ‐edge spectra and chemical component mapping, we concluded that CaCl 2 prefers to coexist with unhydrated C 3 S instead of C‐S‐H. In Si K‐edge NEXAFS analysis, CaCl 2 increases the degree of silicate polymerization of C‐S‐H in agreement with the 29 Si CP/MAS NMR results, which show that the presence of CaCl 2 in hydrated C 3 S considerably accelerates the formation of middle groups ( Q 2 ) and branch sites ( Q 3 ) in the silicate chains of C‐S‐H gel at 1‐day hydration.
Li, Qinfei, et al. "CaCl <sub>2</sub> ‐Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with <sup>29</sup> Si MAS NMR." Journal of Nanomaterials, vol. 2015, no. 1, Jan. 2015. https://doi.org/10.1155/2015/215371
Li, Qinfei, Ge, Yong, Geng, Guoqing, Bae, Sungchul, Monteiro, Paulo J. M., & Choy, ed., Jin-Ho (2015). CaCl <sub>2</sub> ‐Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with <sup>29</sup> Si MAS NMR. Journal of Nanomaterials, 2015(1). https://doi.org/10.1155/2015/215371
Li, Qinfei, Ge, Yong, Geng, Guoqing, et al., "CaCl <sub>2</sub> ‐Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with <sup>29</sup> Si MAS NMR," Journal of Nanomaterials 2015, no. 1 (2015), https://doi.org/10.1155/2015/215371
@article{osti_1227339,
author = {Li, Qinfei and Ge, Yong and Geng, Guoqing and Bae, Sungchul and Monteiro, Paulo J. M. and Choy, ed., Jin-Ho},
title = {CaCl <sub>2</sub> ‐Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with <sup>29</sup> Si MAS NMR},
annote = { The effect of calcium chloride (CaCl 2 ) on tricalcium silicate (C 3 S) hydration was investigated by scanning transmission X‐ray microscopy (STXM) with Near Edge X‐ray Absorption Fine Structure (NEXAFS) spectra and 29 Si MAS NMR. STXM is demonstrated to be a powerful tool for studying the chemical composition of a cement‐based hydration system. The Ca L 3,2 ‐edge NEXAFS spectra obtained by examining C 3 S hydration in the presence of CaCl 2 showed that this accelerator does not change the coordination of calcium in the calcium silicate hydrate (C‐S‐H), which is the primary hydration product. O K‐edge NEXAFS is also very useful in distinguishing the chemical components in hydrated C 3 S. Based on the Ca L 3,2 ‐edge spectra and chemical component mapping, we concluded that CaCl 2 prefers to coexist with unhydrated C 3 S instead of C‐S‐H. In Si K‐edge NEXAFS analysis, CaCl 2 increases the degree of silicate polymerization of C‐S‐H in agreement with the 29 Si CP/MAS NMR results, which show that the presence of CaCl 2 in hydrated C 3 S considerably accelerates the formation of middle groups ( Q 2 ) and branch sites ( Q 3 ) in the silicate chains of C‐S‐H gel at 1‐day hydration. },
doi = {10.1155/2015/215371},
url = {https://www.osti.gov/biblio/1227339},
journal = {Journal of Nanomaterials},
issn = {ISSN 1687-4110},
number = {1},
volume = {2015},
place = {Egypt},
publisher = {Hindawi Publishing Corporation},
year = {2015},
month = {01}}