Civil Engineering
Numerical simulations for the determination of chloride diffusivity in reinforced concrete under tensile load
Publié le - International RILEM Conference on Synergising Expertise towards Sustainability and Robustness of Cement-based Materials and Concrete Structures Synercrete
In service conditions, reinforced concrete structures are multi-cracked due to the loads they are submitted to. It enables aggressive agents, such as chlorides, to penetrate the concrete cover and could initiate steel rebar corrosion leading to more structural damage. Some experimental programs focusing on chloride penetration were conducted on plain or cracked concrete, but mainly unloaded and unreinforced concrete specimens were used for the measurement. These tests highlight the linear dependence of chloride diffusivity to crack opening. However, they do not take into account the presence of rebar, and cracks are partially or totally closed up during the test, which is different from service conditions. This research project aims to understand the influence of micro-and macro-cracks on chloride diffusivity in conditions close to the service ones. To achieve this objective, three steady-state accelerated migration tests under electrical field are to be carried out on a same reinforced concrete specimen kept under a tensile load representative of a structural one. This non-standard chloride penetration test requires the adaptation of the experimental protocol. This paper presents preliminary adaptation work using numerical simulations developed with Comsol Multiphysics®. The impact of testing configuration and parameters, as well as cracking was investigated. Comparison of simulations and preliminary experimental results are also given.