Atomic and nano-scale characterization of a 50-year-old hydrated C{sub 3}S paste
- Department of Civil and Environmental Engineering, University of California at Berkeley (United States)
- Facultad de Ingeniería, Universidad Autónoma de Chiapas, Tuxtla Gutiérrez, Chiapas 29050 (Mexico)
- Advanced Light Source-Lawrence Berkeley National Laboratory, Berkeley, CA (United States)
- NMR Core lab, King Abdullah University of Science and Technology, 23955 Thuwal (Saudi Arabia)
This paper investigates the atomic and nano-scale structures of a 50-year-old hydrated alite paste. Imaged by TEM, the outer product C–S–H fibers are composed of particles that are 1.5–2 nm thick and several tens of nanometers long. {sup 29}Si NMR shows 47.9% Q{sub 1} and 52.1% Q{sub 2}, with a mean SiO{sub 4} tetrahedron chain length (MCL) of 4.18, indicating a limited degree of polymerization after 50 years' hydration. A Scanning Transmission X-ray Microscopy (STXM) study was conducted on this late-age paste and a 1.5 year old hydrated C{sub 3}S solution. Near Edge X-ray Absorption Fine Structure (NEXAFS) at Ca L{sub 3,2}-edge indicates that Ca{sup 2+} in C–S–H is in an irregular symmetric coordination, which agrees more with the atomic structure of tobermorite than that of jennite. At Si K-edge, multi-scattering phenomenon is sensitive to the degree of polymerization, which has the potential to unveil the structure of the SiO{sub 4}{sup 4−} tetrahedron chain.
- OSTI ID:
- 22696528
- Journal Information:
- Cement and Concrete Research, Vol. 77; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
- Country of Publication:
- United States
- Language:
- English
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