مدلسازي اجزا محدود زوال مشخصات مكانيكي اعضاي بتن مسلح در اثر زنگ زدگي ميلگردها

Inspection of 150 bridges in Tehran determines that Reinforcement corrosion is a common defect in concrete bridges. Corrosion occurs in these structures due to malfunctioning of expansion joints and drainages that cause water leakage to structure. Reinforcement corrosion in RC structures leads to severe degradation which usually affects both the capacity and serviceability limit states of the whole structure. Modeling of such a behavior requires effective non linear models able to capture all the main effects of corrosion. This paper discusses these topics by focusing on the effects of corrosion on bond behavior. Interaction between concrete and reinforcement is obtained with defining a interim layer in 3D finite element model and a exact modeling of reinforcement in concrete. A coupled mechanical-environmental damage model is used to simulate the deterioration of concrete (i.e. cover cracking and reduction of mechanical properties) while loss of cross section in reinforcement is also considered. Effect of different levels of corrosion is considered on bond behavior and a good consistency is observed between proposed model and empirical results.