Numerical Simulation Of Durability Deterioration Of RC Bridges Under Chloride Ion Diffusion

With the development of reinforced concrete (RC) structures , the application of RC bridges is becoming more and more widespread. However, the problems along with the process are attracting more attention. Especially in the North Coastal area, the durability problems of the RC bridges induced by the erosion of the chloride ion are serious, which not only reduce the life of the RC bridges but also cause damage to the country.This paper focuses on durability degradation of the RC bridges caused by the corrosion of the chloride ion and the analysis, which aims at the chloride ion diffusion process, the steel corrosion process, the cracking process and the component degradation process, is carried out separately from the environmental level, cross level and component level. Besides, simulation of the RC bridges degrading process is programmed basing on the MATLAB and ANSYS and certain results are acquired as the following.1. A new way to carry out the simulation of the RC bridges degradation is proposed by unifying the 2 2D models built separately from the cross level and the component level, providing a new method to the structural design and structural detection.2. A model based on Celluar Automata(CA) method is proposed to simulate the diffusion process of concrete bridges under various factors such as stress situation, temporal variability, spatial variability and water-cement ratio coupling in the North Coastal area. A chloride ion penetrating test reported in the literature is used to prove this proposed methodology effective, and a T-type beam is taken as an example to analyse the process of chloride ion penetration.3.The process of the steel corrosion is analysed using the electrochemical and metal corrosion theories, which lays the foundation for the cracking process caused by the expansion of corroded steel.4. A 2D component model simulating the process of the durability degradation of the RC bridges is established.