Utilisation de l’ultrason dans les milieux agressifs pour les éléments en béton armés

Abstract

Corrosion of reinforcements is one of the main causes of degradation of concrete. The most common mechanism contributing to the development of corrosion of reinforcements in the marine environment is the penetration of chloride agents. The main risk identified in terms of the durability of marine concretes is related to the penetration of these severely aggressive agents. As the damage resulting from this phenomenon is very important financially, it seems essential to improve the resistance of the concrete to the penetration of these aggressive agents. The aim of this work is to determine experimentally the influence of the corrosion of the reinforcement caused by the penetration of chlorides on the mechanical strength of concrete using ultrasonic waves. Reinforced concrete specimens are then prepared and placed in three different aggressive media, including sea water after a 28-day cure. Subsequently, ultrasonic tests are carried out on these test specimens at different dates. These ultrasonic tests allow us to determine the mechanical strength of the concrete of these test pieces. Finally, we had determined this mechanical strength by means of time curves, compared with the results found experimentally.