چكيده به لاتين
The carbon dioxide present in the air is one of the main reasons of corrosion in bridges, buildings, tunnels and other RC structures in most countries. With the constant increase of pollutants, like carbon dioxide in urban and industrial areas, the probability of corrosion due to carbonation increases. The corrosion process leads to change in mechanical properties of bars and concrete and consequently, bearing capacity and seismic behavior of RC structures will be affected. Neglecting this phenomenon may lead to considerable losses. Therefore, examining the carbonation corrosion on seismic behavior of RC structures in urban and industrial areas is very important. In this study, corrosion phenomenon and its various mechanisms are examined for RC structures. Then, a review of previous studies about bar’s corrosion were conducted and the negative effects of bar corrosion on behavior of RC structures, including loss of cross section and bar strength, cracking and concrete’s loss of strength were examined. In the following, according to the relations examined in this study, corrosion effects on moment curvature curve were studied. Finally, a 2D RC moment frame was developed to study and examine the effect of carbonation corrosion, considering concrete internal factors, environmental factors and operational factors in 5-year periods, for 50 years lifetime. This was done using nonlinear static and incremental dynamic analysis to examine the bar corrosion in a regular basis. Comparing the structure capacity curves in nonlinear static analysis and fragility curves of incremental dynamic analysis for different corrosion scenarios, the amount of capacity loss and seismic behavior of RC frame and the probability of structure failure during its lifetime was determined.
