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Titre :
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Facile preparation of pure CaAl-layered double hydroxides and their application as a hardening accelerator in concrete (2010)
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Auteurs :
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Sailong Xu, Auteur ;
Zhanrui Chen, Auteur ;
Bowen Zhang, Auteur
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Type de document :
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Article : texte imprimé
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Dans :
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Chemical engineering journal (Vol. 155 N° 3, Decembre 2009)
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Article en page(s) :
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pp. 881-885
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Note générale :
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Génie Chimique
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Langues :
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Anglais
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Index. décimale :
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660
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Tags :
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Layered double hydroxides Separate nucleation and aging steps Concrete Hardening accelerator Compressive flexural strength
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Résumé :
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CaAl-layered double hydroxide (CaAl-LDH), one of anionic functional layered materials, has recently been proposed as potential concrete hardening accelerators. Previous laboratory synthesis shows the necessity of employing a protective nitrogen atmosphere to avoid the formation of large amounts of CaCO3 byproduct. Here, we present a preparation of pure CaAl-LDHs which are readily free of contamination by CaCO3. The CaAl-LDHs were prepared via a scalable method of separate nucleation and aging steps (SNAS) by facile introduction of a mixed ethanol/water media. The application of the as-prepared CaAl-LDHs was investigated as a hardening accelerator in concrete. Standard tests of the compressive and flexural strengths of the cement mortars showed that specimens containing CaAl-LDHs as a hardening accelerator exhibited a greatly enhanced performance in respect of early compressive strength and early flexural strength; and the values increased by 61% and 71%, respectively compared to the pristine concrete specimen. The enhanced performances were addressed in terms of the results in situ X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry.
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DEWEY :
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660
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ISSN :
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1385-8947
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En ligne :
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http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X1J78N-2&_user=6909337&_coverDate=12%2F15%2F2009&_rdoc=44&_fmt=high&_orig=browse&_srch=doc-info%28%23toc%235228%232009%23998449996%231562277%23FLA%23display%23Volume%29&_cdi=5228&_sort=d&_doc
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