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Characterization of concrete properties from dielectric properties using ground penetrating radar / W.L. Lai in Cement and concrete research, Vol. 39 N° 8 (Août 2009) 

Public ISBD [article]  in Cement and concrete research > Vol. 39 N° 8 (Août 2009) . - pp. 687–695 Titre : Characterization of concrete properties from dielectric properties using ground penetrating radar Type de document : texte imprimé Auteurs : W.L. Lai, Auteur ; S.C. Kou, Auteur ; W.F. Tsang, Auteur Année de publication : 2009 Article en page(s) : pp. 687–695 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Lightweight  and  normal  aggregate  concrete;  Ground  penetrating  radar;  real  permittivity;  Wave  energy  level;  Free  water;  Absorbed/bound  water Résumé : This paper presents the experimental results of a study of the relationships between light-weight (LWAC) and normal aggregate concrete (NAC) properties, as well as radar wave properties that are derived by using ground penetrating radar (GPR). The former (LWAC) refers to compressive strength, apparent porosity and saturated density, while the latter (NAC) refers to real part of dielectric permittivity (ε' or real permittivity) and wave energy level (E). Throughout the test period of the newly cast concrete cured for 90 days, the above mentioned material properties gradually changed which can be attributed to the effects of cement hydration, different types of aggregates and initial water to binder ratios. A number of plots describing various properties of concrete such as dielectric, strength and porosity perspectives were established. From these plots, we compare the characteristics of how much and how fast free water was turned to absorbed water in LWAC and NAC. The underlying mechanisms and a mechanistic model are then developed. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609001070 [article] Characterization of concrete properties from dielectric properties using ground penetrating radar [texte imprimé] / W.L. Lai, Auteur ; S.C. Kou, Auteur ; W.F. Tsang, Auteur . - 2009 . - pp. 687–695. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 39 N° 8 (Août 2009) . - pp. 687–695 Mots-clés : Lightweight  and  normal  aggregate  concrete;  Ground  penetrating  radar;  real  permittivity;  Wave  energy  level;  Free  water;  Absorbed/bound  water Résumé : This paper presents the experimental results of a study of the relationships between light-weight (LWAC) and normal aggregate concrete (NAC) properties, as well as radar wave properties that are derived by using ground penetrating radar (GPR). The former (LWAC) refers to compressive strength, apparent porosity and saturated density, while the latter (NAC) refers to real part of dielectric permittivity (ε' or real permittivity) and wave energy level (E). Throughout the test period of the newly cast concrete cured for 90 days, the above mentioned material properties gradually changed which can be attributed to the effects of cement hydration, different types of aggregates and initial water to binder ratios. A number of plots describing various properties of concrete such as dielectric, strength and porosity perspectives were established. From these plots, we compare the characteristics of how much and how fast free water was turned to absorbed water in LWAC and NAC. The underlying mechanisms and a mechanistic model are then developed. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609001070