Materials and Structures

, Volume 32, Issue 2, pp 103–111 | Cite as

Lifetime of concrete dam models under constant loads

  • F. Barpi
  • G. Ferrara
  • L. Imperato
  • S. Valente
Scientific Reports

Abstract

This paper presents the results of crack creep tests on three dam models (240 cm high) made with three types of concrete, with maximum aggregate size Φ equal to 3.15, 12 and 25 mm. In order to characterize the material a series of tensile tests was performed for each kind of concrete. In this way the static parameters (Young’s modulusE, ultimate tensile strength σ u , compressive strength σ c , fracture energyG F ) and creep laws were obtained.

The tests on the dam models were performed in many phases: in the last one, the load was kept constant in order to examine the effects of concrete relaxation in terms of Crack Opening Displacement and crack propagation.

Through the Cohesive Crack model it was possible to simulate the experimental results on gravity dam models by using the creep laws obtained from tensile test. Numerical and experimental results (failure lifetime, load vs. C.M.O.D. (Crack Mouth Opening Displacement), C.M.O.D. vs. time, load vs. time, crack trajectories) were found to be in good agreement.

Résumé

Ce travail présente les résultats d’essais de fluage dans la zone endommagée sur trois modèles de barrage en béton (hauts de 240 cm) avec une dimension maximale des granulats de 3, 15, 12 et 25 mm. Le matériau a été caractérisé par des essais de traction pour chaque type de béton. Ainsi ont été déterminés les paramètres statiques (module de Young, résistance maximale à la traction, résistance à la compression, énergie de rupture) et les lois de fluage du béton.

Les essais sur les modèles de barrages ont été conduits en plusieurs phases: dans la dernière, la charge a été gardée constante afin d’examiner les effets de relaxation du matériau en termes d’ouverture de la fissure et de sa propagation.

À travers le modèle de la fissure cohésive, il a été possible de simuler les résultats expérimentaux des essais sur les modèles de barrage en appliquant les lois de fluage obtenus dans les essais de traction. Les résultats numériques et expérimentaux (durée de vie à la fatigue, courbes de charge-ouverture de la fissure, ouverture de la fissure temps, trajectoires des fissures) se sont révélés en bonne corrélation.

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Copyright information

© RILEM 1999

Authors and Affiliations

  • F. Barpi
    • 1
  • G. Ferrara
    • 2
  • L. Imperato
    • 3
  • S. Valente
    • 1
  1. 1.Politecnico di TorinoItaly
  2. 2.E.N.E.L.-C.R.I.S.MilanoItaly
  3. 3.I.S.M.E.S.BergamoItaly

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