CaCl 2 -Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with 29 Si MAS NMR

Li, Qinfei; Ge, Yong; Geng, Guoqing; Bae, Sungchul; Monteiro, Paulo J. M.

doi:10.1155/2015/215371

Title: CaCl ₂ -Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with ²⁹ Si MAS NMR

Full Record
Other Related Research

Abstract

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.

Authors:

Li, Qinfei ^[1]; Ge, Yong ^[2]; Geng, Guoqing ^[3]; Bae, Sungchul ^[4]; Monteiro, Paulo J. M. ^[3]

School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China, Department of Civil and Environmental Engineering, University of California at Berkeley, Berkeley, CA 94720, USA
School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, China
Department of Civil and Environmental Engineering, University of California at Berkeley, Berkeley, CA 94720, USA
Department of Civil and Environmental Engineering, University of California at Berkeley, Berkeley, CA 94720, USA, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamasaki, Noda, Chiba 278-8510, Japan

Publication Date:: Thu Jan 01 00:00:00 EST 2015

Sponsoring Org.:: USDOE

OSTI Identifier:: 1227339

Grant/Contract Number:: AC02-05CH11231

Resource Type:: Published Article

Journal Name:: Journal of Nanomaterials

Additional Journal Information:: Journal Name: Journal of Nanomaterials Journal Volume: 2015; Journal ID: ISSN 1687-4110

Publisher:: Hindawi Publishing Corporation

Country of Publication:: Egypt

Language:: English

Citation Formats


                    Li, Qinfei, Ge, Yong, Geng, Guoqing, Bae, Sungchul, and Monteiro, Paulo J. M. CaCl 2 -Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with 29 Si MAS NMR.  Egypt: N. p., 2015. 
Web.  doi:10.1155/2015/215371.

Copy to clipboard


                    Li, Qinfei, Ge, Yong, Geng, Guoqing, Bae, Sungchul, & Monteiro, Paulo J. M. CaCl 2 -Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with 29 Si MAS NMR.  Egypt.  https://doi.org/10.1155/2015/215371

Copy to clipboard


                    Li, Qinfei, Ge, Yong, Geng, Guoqing, Bae, Sungchul, and Monteiro, Paulo J. M. Thu .  
"CaCl 2 -Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with 29 Si MAS NMR".  Egypt.  https://doi.org/10.1155/2015/215371.

Copy to clipboard


                    
@article{osti_1227339,

  title        = {CaCl 2 -Accelerated Hydration of Tricalcium Silicate: A STXM Study Combined with 29 Si MAS NMR},

  author       = {Li, Qinfei and Ge, Yong and Geng, Guoqing and Bae, Sungchul and Monteiro, Paulo J. M.},

  abstractNote = {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},

  journal      = {Journal of Nanomaterials},

  number       = ,

  volume       = 2015,

  place        = {Egypt},

  year         = {Thu Jan 01 00:00:00 EST 2015},

  month        = {Thu Jan 01 00:00:00 EST 2015}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Publisher's Version of Record
https://doi.org/10.1155/2015/215371

Other availability

Search WorldCat to find libraries that may hold this journal