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High porosity (> 90%) cementitious foams / F.K. Akthar in Cement and concrete research, Vol. 40 N° 2 (02 ex.) (Fevrier 2010) 

Public ISBD [article]  in Cement and concrete research > Vol. 40 N° 2 (02 ex.) (Fevrier 2010) . - pp. 352-358 Titre : High porosity (> 90%) cementitious foams Type de document : texte imprimé Auteurs : F.K. Akthar, Auteur ; J.R.G. Evans, Auteur Année de publication : 2010 Article en page(s) : pp. 352-358 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Microstructure  Compressive  strength  Transport  properties  Fibre  reinforcement  Foams Résumé : High porosity foams based on Portland limestone cement or gypsum plaster were prepared by a simple method of stirring and drying using low levels of the food additives: methyl cellulose and iota carageenan gum. Thermal conductivity of 0.11 W m− 1 K− 1 at 92% porosity was achieved but compressive strength was also very low. Foams were almost closed cell. Attempts to improve strength by incorporation of short staple glass fibre were only partially successful because of a change in the failure mode from progressive collapse to uniform fibre-cement debonding facilitated by the ability of the fibre network to transmit stress throughout the assembly. This approach to fire resistant insulation materials does not yet match the high strength/conductivity ratios of calcium silicate products but deserves exploring because of the simplicity of preparation and the compositional freedom for using mixtures of hydraulic cement and other powders. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWG-4XMC05Y-1&_user=6 [...] [article] High porosity (> 90%) cementitious foams [texte imprimé] / F.K. Akthar, Auteur ; J.R.G. Evans, Auteur . - 2010 . - pp. 352-358. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 40 N° 2 (02 ex.) (Fevrier 2010) . - pp. 352-358 Mots-clés : Microstructure  Compressive  strength  Transport  properties  Fibre  reinforcement  Foams Résumé : High porosity foams based on Portland limestone cement or gypsum plaster were prepared by a simple method of stirring and drying using low levels of the food additives: methyl cellulose and iota carageenan gum. Thermal conductivity of 0.11 W m− 1 K− 1 at 92% porosity was achieved but compressive strength was also very low. Foams were almost closed cell. Attempts to improve strength by incorporation of short staple glass fibre were only partially successful because of a change in the failure mode from progressive collapse to uniform fibre-cement debonding facilitated by the ability of the fibre network to transmit stress throughout the assembly. This approach to fire resistant insulation materials does not yet match the high strength/conductivity ratios of calcium silicate products but deserves exploring because of the simplicity of preparation and the compositional freedom for using mixtures of hydraulic cement and other powders. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TWG-4XMC05Y-1&_user=6 [...]