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Prediction of bond between steel and concrete by numerical analysis

  • H. W. Reinhardt
  • J. Blaauwendraad
  • E. Vos
Article

Abstract

Since bond between steel and concrete is an essential requirement for reinforced concrete it should be known as a function of many variables. In the past, many variables have been investigated by experiments within a certain range. Extrapolation to other ranges or other variables is not always reliable.

Therefore an attempt has been made to model bond in a numerical way only by making use of the shape of the steel bar and the properties of concrete which are known in a wider range than bond. In the study much attention is paid to the concrete adjacent to the reinforcing bar. It is assumed that there is a concrete layer around the bar which is stressed to a much higher extent than the remaining part of the structure. This layer is treated by non-linear finite element analysis taking into account the triaxial behaviour of concrete. The deformation of the concrete under bond forces is formulated in terms of stresses and displacements acting at the surface of this layer. These can be used as input for a linear elastic analysis of the remainder of the concrete part.

The results of the numerical analysis are compared with experimental results of static and impact loading and additional transverse compression stresses showing good agreement. The method may be used in the future to predict bond behaviour of deformed bars under other conditions like low and high temperature, various humidities, sustained loading and other types of concrete.

Keywords

Impact Loading Strength Concrete High Strength Concrete Radial Pressure Bond Stress 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Résumé

L'adhérence acier-béton est pour le béton armé une exigence telle qu'il est nécessaire de la connaître en fonction de plusieurs variables.

Dans le passé, plusieurs variables ont fait l'objet d'essais mais il n'est pas toujours exact d'extrapoler pour d'autres valeurs ou d'autres variables.

Une tentative a donc été faite d'évaluer l'adhérence par modélisation à partir de la forme de la barre d'acier et des caractéristiques du béton beaucoup mieux connues que l'adhérence. Dans cette étude, on tient beaucoup plus compte du béton d'enrobage et l'on part du principe que la couche de béton autour de la barre est soumise à des tensions plus élevées que dans le reste de la structure. Pour étudier cette couche, on a eu recours à l'analyse par éléments finis non linéaires compte tenu du comportement triaxial du béton. Les déformations du béton, sous des efforts d'adhérence, sont formulées en termes de tensions et de déplacements agissant à la surface de cette couche.

L'application peut en être faite pour l'analyse linéaire élastique de la partie restante du béton.

On compare les résultats de l'analyse numérique avec les résultats d'essais de chargement statique et d'essais de choc, ainsi qu'avec les contraintes de compression supplémentaires qui montrent une bonne concordance. On peut envisager d'utiliser la méthode pour prédire le comportement d'adhérence de barres déformées dans d'autres conditions: températures élevées ou basses, humidités différentes, charges constantes ou autres types de béton.

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Copyright information

© Bordas-Gauthier-Villars 1984

Authors and Affiliations

  • H. W. Reinhardt
    • 1
  • J. Blaauwendraad
    • 2
  • E. Vos
    • 3
  1. 1.Delft University of TechnologyThe Netherlands
  2. 2.Structural ResearchPublic State WorksThe Netherlands
  3. 3.Road Engineering DivisionPublics State WorksThe Netherlands

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