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Matériaux et Construction

, Volume 17, Issue 2, pp 149–155 | Cite as

The effect of the longitudinal stiffness of the testing machine on the strength of hardened cement paste

  • S. Mindess
  • A. Bentur
Article
  • 82 Downloads

Abstract

Tests were carried out to see whether the longitudinal stiffness of the testing machine had any effect on the strength and fracture toughness of hardened cement paste. Six different testing machines were studied; in addition, machine stiffness was varied by inserting proving rings in series with the specimens. It was found that machine stiffness has no significant effect on the compressive strength, the flexural strength, or the critical stress intensity factor.

Keywords

Compressive Strength Flexural Strength Critical Stress Intensity Factor Hardened Cement Longitudinal Stiffness 
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

Six machines d'essai de différents types et de rigidité différentes ont servi à l'examen des effets de la rigidité longitudinale du système de chargement sur les résistances en compression et en flexion de la pâte de ciment durcie et sur sa résistance aux chocs (KIC). En outre, les rigidités des machines ont été encore diversifiées par l'insertion d'anneaux dynamométriques de différentes rigidités en série avec certaines des éprouvettes. La rigidité de la machine d'essai a été caractérisée par la réponse complète contrainte/flèche de la machine à vide car les courbes chargement/déchargement n'étaient pas nécessairement linéaires et que les courbes ont montré une hystérésis importante. On a constaté d'importantes variations de rigidité de machine à machine et même pour la même machine à différents niveaux de charge.

Avec l'essai de Student, on a constaté que, au niveau 1% ni le type de la machine d'essai ni sa rigidité n'influent sur les résistances en compression. Il n'apparaît pas non plus d'effet de dimension dans ces essais. On n'a pas constaté de variation notable des résistances en flexion de machine à machine au niveau 5%. Enfin, la résistance aux chocs se révèle être indépendante de la rigidité de la machine toujours au niveau 1%.

La rigidité longitudinale de la machine d'essai paraît donc avoir peu ou pas d'effet tant sur la résistance statique que sur la résistance aux chocs de la pâte de ciment durcie. Les différences qui peuvent se produire s'expliqueraient en termes d'effets d'extrémités ou par la rigidité latérale de la machine.

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Copyright information

© Bordas-Gauthier-Villars 1984

Authors and Affiliations

  • S. Mindess
    • 1
  • A. Bentur
    • 2
  1. 1.Department of Civil EngineeringUniversity of British ColumbiaVancouverCanada
  2. 2.Building Materials Department, Building Research StationFaculty of Civil Engineering, TechnionHaifaIsrael

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