TY - JOUR
T1 - Intrinsic differences in atomic ordering of calcium (alumino)silicate hydrates in conventional and alkali-activated cements
AU - White, Claire Emily
AU - Daemen, Luke L.
AU - Hartl, Monika
AU - Page, Katharine
N1 - Funding Information:
The participation of all authors in this work was supported by Los Alamos National Laboratory, which is operated by Los Alamos National Security LLC under DOE Contract DE-AC52-06NA25396 . Furthermore, CEW gratefully acknowledges the support of the U.S. Department of Energy through the LANL/LDRD Program. The 11-ID-B beam line is located at the Advanced Photon Source, an Office of Science User Facility operated for the U.S. DOE Office of Science by Argonne National Laboratory, under U.S. DOE Contract No. DE-AC02-06CH11357. The authors would like to acknowledge the support and assistance of the beam line staff on 11-ID-B, and access to the beam line via a Partner User Proposal between 11-ID-B and the neutron PDF instrument NOMAD at SNS, ORNL.
Publisher Copyright:
© 2014 Elsevier Ltd.
PY - 2015/1
Y1 - 2015/1
N2 - The atomic structures of calcium silicate hydrate (C-S-H) and calcium (-sodium) aluminosilicate hydrate (C-(N)-A-S-H) gels, and their presence in conventional and blended cement systems, have been the topic of significant debate over recent decades. Previous investigations have revealed that synthetic C-S-H gel is nanocrystalline and due to the chemical similarities between ordinary Portland cement (OPC)-based systems and low-CO2 alkali-activated slags, researchers have inferred that the atomic ordering in alkali-activated slag is the same as in OPC-slag cements. Here, X-ray total scattering is used to determine the local bonding environment and nanostructure of C(-A)-S-H gels present in hydrated tricalcium silicate (C3S), blended C3S-slag and alkali-activated slag, revealing the large intrinsic differences in the extent of nanoscale ordering between C-S-H derived from C3S and alkali-activated slag systems, which may have a significant influence on thermodynamic stability, and material properties at higher length scales, including long term durability of alkali-activated cements.
AB - The atomic structures of calcium silicate hydrate (C-S-H) and calcium (-sodium) aluminosilicate hydrate (C-(N)-A-S-H) gels, and their presence in conventional and blended cement systems, have been the topic of significant debate over recent decades. Previous investigations have revealed that synthetic C-S-H gel is nanocrystalline and due to the chemical similarities between ordinary Portland cement (OPC)-based systems and low-CO2 alkali-activated slags, researchers have inferred that the atomic ordering in alkali-activated slag is the same as in OPC-slag cements. Here, X-ray total scattering is used to determine the local bonding environment and nanostructure of C(-A)-S-H gels present in hydrated tricalcium silicate (C3S), blended C3S-slag and alkali-activated slag, revealing the large intrinsic differences in the extent of nanoscale ordering between C-S-H derived from C3S and alkali-activated slag systems, which may have a significant influence on thermodynamic stability, and material properties at higher length scales, including long term durability of alkali-activated cements.
KW - Alkali-activated cement
KW - Amorphous material (B)
KW - Calcium-silicate-hydrate (C-S-H) (B)
KW - Portland cement (D)
KW - X-ray diffraction (B)
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U2 - 10.1016/j.cemconres.2014.08.006
DO - 10.1016/j.cemconres.2014.08.006
M3 - Article
AN - SCOPUS:84907901539
SN - 0008-8846
VL - 67
SP - 66
EP - 73
JO - Cement and Concrete Research
JF - Cement and Concrete Research
ER -