TY - JOUR
T1 - Silica-modifying chemical admixtures for directed zeolitization of metakaolin-based alkali-activated materials
AU - Osio-Norgaard, J.
AU - Aday, A. N.
AU - Chen, X.
AU - Williams, S. L.
AU - Gevaudan, J. P.
AU - Srubar, W. 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 (LMLab) at the University of Colorado Boulder , with financial support from the National Science Foundation (NSF) (Award No. CBET-1604457 ), the NSF Graduate Research Fellowship Program, and the Advanced Research Projects Agency-Energy (Award Number: DE-AR0001145 ). Dr. J.P. Gevaudan's participation in this study was supported by the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 839436 . Additionally, the authors would like to thank the United States Geological Survey, BASF for the donation of MK from BASF, and SACHEM for donating the adamantium hydroxide. This work represents the views of the authors and not necessarily those of the sponsors.
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/4
Y1 - 2021/4
N2 - The effect of using trimethyladamantyl-ammonium hydroxide (TMAAOH) as a silica-modifying admixture to induce early-age mineralization during alkali-activation of metakaolin was investigated and reported herein. In all material formulations, the use of TMAAOH induced early-age mineralization, increased mixture stiffening in the fresh state, and lowered total heat of reaction. In activating solutions with silica moduli above unity (Ms >1.0), mineralogy results demonstrate that TMAAOH induces the nucleation and growth of metastable zeolitic phases, which correlated with increased permeability and increased plastic shrinkage of the paste. When TMAAOH was added to activating solutions with silica moduli near unity (Ms ~1.0), the controlled formation of crystalline, silica-rich faujasite was observed, which correlated with reduced permeability and lower plastic shrinkage. Together, these results demonstrate for the first time that silica-templating agents such as TMAAOH can be exploited in the deisgn of new chemical admixtures that directly influence the dynamics of zeolitization in alkali-activated materials.
AB - The effect of using trimethyladamantyl-ammonium hydroxide (TMAAOH) as a silica-modifying admixture to induce early-age mineralization during alkali-activation of metakaolin was investigated and reported herein. In all material formulations, the use of TMAAOH induced early-age mineralization, increased mixture stiffening in the fresh state, and lowered total heat of reaction. In activating solutions with silica moduli above unity (Ms >1.0), mineralogy results demonstrate that TMAAOH induces the nucleation and growth of metastable zeolitic phases, which correlated with increased permeability and increased plastic shrinkage of the paste. When TMAAOH was added to activating solutions with silica moduli near unity (Ms ~1.0), the controlled formation of crystalline, silica-rich faujasite was observed, which correlated with reduced permeability and lower plastic shrinkage. Together, these results demonstrate for the first time that silica-templating agents such as TMAAOH can be exploited in the deisgn of new chemical admixtures that directly influence the dynamics of zeolitization in alkali-activated materials.
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U2 - 10.1016/j.cemconres.2020.106348
DO - 10.1016/j.cemconres.2020.106348
M3 - Article
AN - SCOPUS:85099447071
VL - 142
JO - Cement and Concrete Research
JF - Cement and Concrete Research
SN - 0008-8846
M1 - 106348
ER -