Miguel Molero - Academia.edu (original) (raw)
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Papers by Miguel Molero
Construction and Building Materials, 2011
In this paper, the influence of steel fibers on the ultrasonic velocity of steel-fiber-reinforced... more In this paper, the influence of steel fibers on the ultrasonic velocity of steel-fiber-reinforced cementitious materials was studied using a micromechanical model. To this end, a three-phase micromechanical model was extended and generalized to multiphase materials. Firstly, such a model was used to predict the influence of the geometry and volume fraction of steel inclusions on the ultrasonic velocity of steelfiber-reinforced cementitious materials. Experimental validation was carried out on steel-reinforced and non-reinforced mortar specimens through destructive and non-destructive testing by ultrasound. Comparisons between predicted and measured ultrasonic velocity were in good agreement, with errors less than 1.5%. Moreover, the model was also validated on experimental data obtained from steel-fiber-reinforced concrete specimens [Yazıcı et al. Constr Build Mater 2007;21:1250-3].
The quality and degradation state of building materials can be determined by means of nondestruct... more The quality and degradation state of building materials can be determined by means of nondestructive testing (NDT). These materials are composed by a cementitious matrix and several aggregates, generally sand and gravel. Sand/cement ratio (s/c) provides the final material quality; however, the sand content can mask the matrix properties in a nondestructive measurement.
European Journal of Environmental and Civil Engineering, 2011
This paper examines the influence of the size and volume fraction of both aggregates and air void... more This paper examines the influence of the size and volume fraction of both aggregates and air voids on the ultrasonic phase velocity and attenuation coefficient measured in cementitious specimens. A multiphase approach of the Waterman-Truell (WT) model was used to study theoretically how the size and volume fraction of the constituents in cementitious materials affect velocity and attenuation profiles. To verify the theoretical results obtained by the model, ultrasonic measurements were performed in several cementitious specimens with different granulometries of elastic aggregates (glass microspheres). Both theoretical and experimental results showed that velocity information can largely identify changes in the volume fraction of aggregates, whereas attenuation information is more sensible to variations in the aggregate size.Cet article examine l'influence de la taille et la fraction volumique des deux agrégats, et les vides d'air sur la vitesse de phase ultrasonique et l'atténuation, mesurée dans des matériaux cimentaires. Une approche polyphasique du modèle de Waterman-Truell (WT) est utilisée pour étudier théoriquement la façon dont la taille et la fraction volumique des constituants des matériaux cimentaires affectent les profils de vitesse et d'atténuation. Les mesures ultrasoniques sont faites à partir d'échantillons de ciment avec des granulométries différentes des agrégats élastiques (microsphères de verre). Les deux résultats théoriques et expérimentaux montrent que les informations sur la vitesse peuvent largement identifier les changements dans la fraction du volume des agrégats, alors que les informations d'atténuation sont plus sensibles aux variations de taille des agrégats.
Construction and Building Materials, 2011
In this paper, the influence of steel fibers on the ultrasonic velocity of steel-fiber-reinforced... more In this paper, the influence of steel fibers on the ultrasonic velocity of steel-fiber-reinforced cementitious materials was studied using a micromechanical model. To this end, a three-phase micromechanical model was extended and generalized to multiphase materials. Firstly, such a model was used to predict the influence of the geometry and volume fraction of steel inclusions on the ultrasonic velocity of steelfiber-reinforced cementitious materials. Experimental validation was carried out on steel-reinforced and non-reinforced mortar specimens through destructive and non-destructive testing by ultrasound. Comparisons between predicted and measured ultrasonic velocity were in good agreement, with errors less than 1.5%. Moreover, the model was also validated on experimental data obtained from steel-fiber-reinforced concrete specimens [Yazıcı et al. Constr Build Mater 2007;21:1250-3].
The quality and degradation state of building materials can be determined by means of nondestruct... more The quality and degradation state of building materials can be determined by means of nondestructive testing (NDT). These materials are composed by a cementitious matrix and several aggregates, generally sand and gravel. Sand/cement ratio (s/c) provides the final material quality; however, the sand content can mask the matrix properties in a nondestructive measurement.
European Journal of Environmental and Civil Engineering, 2011
This paper examines the influence of the size and volume fraction of both aggregates and air void... more This paper examines the influence of the size and volume fraction of both aggregates and air voids on the ultrasonic phase velocity and attenuation coefficient measured in cementitious specimens. A multiphase approach of the Waterman-Truell (WT) model was used to study theoretically how the size and volume fraction of the constituents in cementitious materials affect velocity and attenuation profiles. To verify the theoretical results obtained by the model, ultrasonic measurements were performed in several cementitious specimens with different granulometries of elastic aggregates (glass microspheres). Both theoretical and experimental results showed that velocity information can largely identify changes in the volume fraction of aggregates, whereas attenuation information is more sensible to variations in the aggregate size.Cet article examine l'influence de la taille et la fraction volumique des deux agrégats, et les vides d'air sur la vitesse de phase ultrasonique et l'atténuation, mesurée dans des matériaux cimentaires. Une approche polyphasique du modèle de Waterman-Truell (WT) est utilisée pour étudier théoriquement la façon dont la taille et la fraction volumique des constituants des matériaux cimentaires affectent les profils de vitesse et d'atténuation. Les mesures ultrasoniques sont faites à partir d'échantillons de ciment avec des granulométries différentes des agrégats élastiques (microsphères de verre). Les deux résultats théoriques et expérimentaux montrent que les informations sur la vitesse peuvent largement identifier les changements dans la fraction du volume des agrégats, alors que les informations d'atténuation sont plus sensibles aux variations de taille des agrégats.