Coordination environment of Si in calcium silicate hydrates, silicate minerals, and blast furnace slags: A XANES database
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720 (United States)
- Institute for Technical Chemistry, Karlsruhe Institute of Technology, 76021 Karlsruhe (Germany)
Understanding the silicate polymerization of calcium silicate hydrate (C-S-H) gel and its crystalline polymorphs is important in cement science. NMR can determine Si environments, but the measurement can be time-consuming and provides no spatial information. X-ray absorption near-edge structure (XANES) spectroscopy is a fast tool for probing Si coordination, possibly with spatial information. However, there lacks an understanding of Si K-edge XANES spectra of cement-related silicate phases. Here, a Si K-edge XANES spectral database of nanocrystalline C-S-H, C-S-H minerals, blast-furnace slags, and metakaolin is provided. Si K-edge of C-S-H minerals shifts to higher energies with higher polymerized Si and lower CaSi connectivity in the Si second nearest neighbor shell. Si K-edge energy shows weak correlations with Ca/Si ratio, average SiO bond length, and SiO{sub 4} distortion due to the structural complexity of silicates. The substitution of Al for Si shifts the Si K-edge of tobermorite and slags to higher energies.
- OSTI ID:
- 23206336
- Journal Information:
- Cement and Concrete Research, Journal Name: Cement and Concrete Research Vol. 143; ISSN 0008-8846; ISSN CCNRAI
- Country of Publication:
- United States
- Language:
- English
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