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Hydration in high-performance cementitious systems containing vitreous calcium aluminosilicate or silica fume / Narayanan Neithalath in Cement and concrete research, Vol. 39 N° 6 (Juin 2009) 

Public ISBD [article]  in Cement and concrete research > Vol. 39 N° 6 (Juin 2009) . - pp. 473–481 Titre : Hydration in high-performance cementitious systems containing vitreous calcium aluminosilicate or silica fume Type de document : texte imprimé Auteurs : Narayanan Neithalath, Auteur ; Jarrod Persun, Auteur ; Akhter Hossain, Auteur Année de publication : 2009 Article en page(s) : pp. 473–481 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Hydration  ;  Degree  of  hydration  ;  Silica  fume  ;  Porosity;  Vitreous  calcium  aluminosilicate;  Non-evaporable  water  content Résumé : The influence of a relatively new high-performance cement replacement material—vitreous calcium aluminosilicate (VCAS)—on the hydration behavior in cementitious systems, and its comparison to silica fume (SF) are presented in this paper. VCAS is shown to have no cementitious qualities, but exhibits significant pozzolanicity, which has been quantified using strength activity index and electrical conductivity change. VCAS modified pastes are found to consume more water during hydration than the corresponding SF modified pastes. Based on a normalized calcium hydroxide content defined in this paper, it is seen that the pozzolanic reaction of VCAS does not happen until 7 days while that of SF occurs as early as the first day. The degrees of hydration of the modified pastes are predicted using a model that employs the change in non-evaporable water resulting from the use of these replacement materials. VCAS modified pastes show lower later age porosities as compared to the plain and SF modified pastes. However, at equal degrees of hydration, SF modified pastes show the lowest porosity. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609000556 [article] Hydration in high-performance cementitious systems containing vitreous calcium aluminosilicate or silica fume [texte imprimé] / Narayanan Neithalath, Auteur ; Jarrod Persun, Auteur ; Akhter Hossain, Auteur . - 2009 . - pp. 473–481. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 39 N° 6 (Juin 2009) . - pp. 473–481 Mots-clés : Hydration  ;  Degree  of  hydration  ;  Silica  fume  ;  Porosity;  Vitreous  calcium  aluminosilicate;  Non-evaporable  water  content Résumé : The influence of a relatively new high-performance cement replacement material—vitreous calcium aluminosilicate (VCAS)—on the hydration behavior in cementitious systems, and its comparison to silica fume (SF) are presented in this paper. VCAS is shown to have no cementitious qualities, but exhibits significant pozzolanicity, which has been quantified using strength activity index and electrical conductivity change. VCAS modified pastes are found to consume more water during hydration than the corresponding SF modified pastes. Based on a normalized calcium hydroxide content defined in this paper, it is seen that the pozzolanic reaction of VCAS does not happen until 7 days while that of SF occurs as early as the first day. The degrees of hydration of the modified pastes are predicted using a model that employs the change in non-evaporable water resulting from the use of these replacement materials. VCAS modified pastes show lower later age porosities as compared to the plain and SF modified pastes. However, at equal degrees of hydration, SF modified pastes show the lowest porosity. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609000556