TY - JOUR
T1 - Atomic structure and phase assemblages in novel M-(N)-A-S-H materials
AU - Bedeaux, Matthew
AU - Gevaudan, Juan Pablo
AU - Lama, Bimala
AU - Srubar, Wil V.
N1 - Funding Information:
This research was made possible by the Department of Civil, Environmental, and Architectural Engineering, the College of Engineering and Applied Sciences, and the Living Materials Laboratory at the University of Colorado Boulder. This work was supported by the National Science Foundation grant CBET-1604457 . Dr. Kate Campbell and Mr. Tyler Kane of the United States Geological Survey (USGS) are gratefully acknowledged for their assistance with XRD. Dr. J.P. Gevaudan's participation to supervise, guide and complete this study was supported by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 839436 . This work represents the views of the authors and not necessarily those of the sponsors.
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2021/4
Y1 - 2021/4
N2 - This paper investigates the atomic structure and phase assemblages in new sodium-stabilized magnesium aluminosilicate hydrate (M-(N)-A-S-H) cementitious binders. Results indicate that in the absence of Ca2+, Mg2+ promotes a binder atomic structure of Si-Al tetrahedral sheets and octahedral Mg sheets with hydrated Na+ cations likely in the interlayer sites similar to trioctahedral micas (phyllosilicates). NMR studies verify the incorporation of Al in tetrahedral silicate sheets. XRD demonstrates the ability of these regions to nucleate and form zeolites (i.e., sodalite) as well as the formation of Mg-Al layered double hydroxide (LDH) phases (i.e., meixnerite), which is expected due to high concentrations of Mg and Al. TGA results indicate that M-(N)-A-S-H possesses chemically bound water and hydroxyl units similar to other Mg binders. These results evince the critical role of Mg to form unique atomic structures and durability-linked phases in low-calcium alkali-activated materials.
AB - This paper investigates the atomic structure and phase assemblages in new sodium-stabilized magnesium aluminosilicate hydrate (M-(N)-A-S-H) cementitious binders. Results indicate that in the absence of Ca2+, Mg2+ promotes a binder atomic structure of Si-Al tetrahedral sheets and octahedral Mg sheets with hydrated Na+ cations likely in the interlayer sites similar to trioctahedral micas (phyllosilicates). NMR studies verify the incorporation of Al in tetrahedral silicate sheets. XRD demonstrates the ability of these regions to nucleate and form zeolites (i.e., sodalite) as well as the formation of Mg-Al layered double hydroxide (LDH) phases (i.e., meixnerite), which is expected due to high concentrations of Mg and Al. TGA results indicate that M-(N)-A-S-H possesses chemically bound water and hydroxyl units similar to other Mg binders. These results evince the critical role of Mg to form unique atomic structures and durability-linked phases in low-calcium alkali-activated materials.
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U2 - 10.1016/j.cemconres.2020.106336
DO - 10.1016/j.cemconres.2020.106336
M3 - Article
AN - SCOPUS:85099518505
VL - 142
JO - Cement and Concrete Research
JF - Cement and Concrete Research
SN - 0008-8846
M1 - 106336
ER -