TY - JOUR
T1 - Atomic and nano-scale characterization of a 50-year-old hydrated C3S paste
AU - Geng, Guoqing
AU - Taylor, Rae
AU - Bae, Sungchul
AU - Hernández-Cruz, Daniel
AU - Kilcoyne, David A.
AU - Emwas, Abdul-Hamid M.
AU - Monteiro, Paulo J. M.
N1 - KAUST Repository Item: Exported on 2020-10-01
PY - 2015/7/16
Y1 - 2015/7/16
N2 - 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. 29Si NMR shows 47.9% Q1 and 52.1% Q2, with a mean SiO4 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 C3S solution. Near Edge X-ray Absorption Fine Structure (NEXAFS) at Ca L3,2-edge indicates that Ca2 + 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 SiO44 - tetrahedron chain. © 2015 Elsevier Ltd. All rights reserved.
AB - 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. 29Si NMR shows 47.9% Q1 and 52.1% Q2, with a mean SiO4 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 C3S solution. Near Edge X-ray Absorption Fine Structure (NEXAFS) at Ca L3,2-edge indicates that Ca2 + 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 SiO44 - tetrahedron chain. © 2015 Elsevier Ltd. All rights reserved.
UR - http://hdl.handle.net/10754/566075
UR - https://manuscript.elsevier.com/S0008884615001799/pdf/S0008884615001799.pdf
UR - http://www.scopus.com/inward/record.url?scp=84937042423&partnerID=8YFLogxK
U2 - 10.1016/j.cemconres.2015.06.010
DO - 10.1016/j.cemconres.2015.06.010
M3 - Article
SN - 0008-8846
VL - 77
SP - 36
EP - 46
JO - Cement and Concrete Research
JF - Cement and Concrete Research
ER -