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Materials and Structures

, Volume 36, Issue 4, pp 218–225 | Cite as

Mechanical properties of young concrete: Part I: Experimental results related to test methods and temperature effects

  • T. Kanstad
  • T. A. Hammer
  • Ø. Bjøntegaard
  • E. J. Sellevold
Article

Abstract

Results of several test series on mechanical properties of young concrete are presented. Six different concrete mixes were tested systematically, and a number of other concrete mixes less extensively, all with w/b≈0.40. The program included compressive strength, tensile strength, splitting tensile strength and E-modulus determination both in compression and tension. Because temperature influences the rate of property development, and also the “final value” of a given property, the specimens were subjected to realistic temperature regimes the first few days as well as isothermal conditions. The test methods are described, and results obtained by the different test methods are compared. It is recommended that the temperature sensitivity constants should be determined from compressive strength tests on specimens exposed to realistic temperature histories. These parameters depend strongly on the cement type and the silica fume content. It was found that high performance concretes were quite robust to the negative effects of elevated temperatures. This was particularly true for concretes with pozzolana. In part two of the paper model parameters for an equation to be used in calculation programs are determined, and a test program for crack risk estimation is proposed.

Keywords

Compressive Strength Silica Fume High Strength Concrete High Performance Concrete Splitting Tensile Strength 
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

Dans ce rapport sont présentés les résultats de plusieurs séries d’essais sur les propriétés mécaniques du béton jeune. Six mélanges différents ont été testés de façon systématique, et quelques autres de manière moins approfondie. Le but de ces expériences était de déterminer la résistance en compression et en traction, la résistance à la rupture en traction ainsi que le module d’élasticité, à la fois en compression et en traction. Comme la température influence la façon dont évoluent les caractéristiques du béton, ainsi que la «valeur finale» d’une caractéristique donnée, les échantillons ont été soumis durant les premiers jours d’une part à des régimes de températures semblables aux conditions naturelles, et d’autre part à des conditions isothermiques.

Sont ici données une description des méthodes expérimentales utilisées et une comparaison des différents résultats obtenus. Il est recommandé de déterminer les constantes de sensibilité à la température à partir des essais de résistance en compression sur les échantillons soumis aux variations de températures. Ces paramètres dépendent beaucoup du type de ciment et de la quantité de fumée de silice contenus dans le mélange. On a remarqué que les bétons à hautes performances résistaient plutôt bien aux conséquences négatives des températures élevées. Ceci est vrai en particulier pour les bétons contenant du ciment pouzzolanique.

Dans la seconde partie de ce rapport, les paramètres de modélisation pour l’équation MC1990 modifiée sont déterminés, pour les six mélanges, dans le cas de la résistance en compression et en traction, et du module d’élasticité. En outre, il est proposé un programme expérimental destiné à l’évaluation des risques de fissuration.

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References

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Copyright information

© RILEM 2003

Authors and Affiliations

  • T. Kanstad
    • 1
  • T. A. Hammer
    • 2
  • Ø. Bjøntegaard
    • 1
  • E. J. Sellevold
    • 1
  1. 1.Department of Structural EngineeringThe Norwegian University of Science and Technology (NTNU)TrondheimNorway
  2. 2.SINTEF, Civil and Environmental EngineeringTrondheimNorway

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