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Characterization of elastic and time-dependent deformations in high performance lightweight concrete by image analysis / Mauricio Lopez in Cement and concrete research, Vol. 39 N° 7 (Juillet 2009) 

Public ISBD [article]  in Cement and concrete research > Vol. 39 N° 7 (Juillet 2009) . - pp. 610–619 Titre : Characterization of elastic and time-dependent deformations in high performance lightweight concrete by image analysis Type de document : texte imprimé Auteurs : Mauricio Lopez, Auteur ; Lawrence F. Kahn, Auteur ; Kimberly E. Kurtis, Auteur Année de publication : 2009 Article en page(s) : pp. 610–619 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Aggregate;  Cement  paste;  Creep;  Interfacial  transition  zone;  Shrinkage Résumé : Image analysis and strain mapping were used to examine the nature of elastic, creep and shrinkage strains in high performance lightweight concrete (HPLC). The strain maps showed non-uniform deformations related to microstructural features. Both average strain and non-uniformity increased with time under testing. Paste-rich regions exhibited higher creep plus shrinkage than the lightweight aggregate (LWA) particles examined herein; it is suggested that LWA could have a role in reducing deformations of the paste. Compared to normal weight high performance concrete (HPC), the paste and LWA in the HPLC exhibited more gradual spatial differences in elastic deformations, creep and shrinkage. It is proposed that this difference results from the lower stiffness of the LWA compared to granite used in the HPC. The results indicate that improvement in elastic property matching between the lightweight aggregate and high performance paste reduces stress concentrations at the aggregate/paste interface and contributes to reductions in deformations of HPLC compared to HPC. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609000763 [article] Characterization of elastic and time-dependent deformations in high performance lightweight concrete by image analysis [texte imprimé] / Mauricio Lopez, Auteur ; Lawrence F. Kahn, Auteur ; Kimberly E. Kurtis, Auteur . - 2009 . - pp. 610–619. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 39 N° 7 (Juillet 2009) . - pp. 610–619 Mots-clés : Aggregate;  Cement  paste;  Creep;  Interfacial  transition  zone;  Shrinkage Résumé : Image analysis and strain mapping were used to examine the nature of elastic, creep and shrinkage strains in high performance lightweight concrete (HPLC). The strain maps showed non-uniform deformations related to microstructural features. Both average strain and non-uniformity increased with time under testing. Paste-rich regions exhibited higher creep plus shrinkage than the lightweight aggregate (LWA) particles examined herein; it is suggested that LWA could have a role in reducing deformations of the paste. Compared to normal weight high performance concrete (HPC), the paste and LWA in the HPLC exhibited more gradual spatial differences in elastic deformations, creep and shrinkage. It is proposed that this difference results from the lower stiffness of the LWA compared to granite used in the HPC. The results indicate that improvement in elastic property matching between the lightweight aggregate and high performance paste reduces stress concentrations at the aggregate/paste interface and contributes to reductions in deformations of HPLC compared to HPC. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609000763