Myriam Carcassès

Simplified models for the engineering of concrete formulations in a marine environment through a probabilistic method

This article aims to expose a probabilistic methodology for the design of concrete formulations in a marine environment. As defined in the performance-based approach, durability indicators, considered as random variables, will be defined by quantifying their variability. Based on elementary models for engineers, a classical probabilistic approach is then proposed: the probability to depassivate the reinforced bars, through a reliability index, is estimated in order to insure the durability of concrete. Moreover, a Bayesian network is used to update the distributions of random variables. Cet article expose une approche probabiliste pour l’élaboration de formulations de béton en environnement marin. Similairement à l’approche performantielle, des témoins de de durabilité, considérés comme des variables aléatoires, sont caractérisés par leur variabilité. Sur la base de modèles simples, une approche probabiliste classique est proposée: la probabilité de dépassivation des aciers passifs, au travers d’un indice de fiabilité, est estimée afin d’assurer la durabilité du béton. De plus, un réseau bayésien est utilisé pour actualiser les lois de ces variables aléatoires.

Approche performantielle probabilisée pour la durabilité des bétons d'ouvrages en environnement marin

ABSTRACT The performance-type approach of durability is used for the study of an immersed concrete in sea water. The general and complementary durability indicators are exposed. To take into account the variability of those parameters, a probabilistic approach is proposed. Based on the concrete formulation and the chemical cement composition, the durability indicators are evaluated with the associated incertitude. The corrosion risk is estimated through the Lind-Hasofer reliability index. The application of this complete methodology has succeeded in validated the performance-type approach.