Propagation of corrosion and corrosion patterns of bars embedded in RC beams stored in chloride environment for various periods

In this paper, the propagation of chloride-induced corrosion of bars embedded in reinforced concrete (RC) beams exposed to a chloride environment was examined. These bars were exposed to chloride environment for various periods. Then, the cracking of the RC beams was observed and the corroded reinforcements were extracted from the beams in order to investigate the corrosion distribution and propagation. The cross-sectional loss and spatial distribution in the longitudinal direction were studied by cutting the residual reinforcement into several small specimens. By analysing the cross-sectional loss results, it was found that the corrosion developed in a stochastic way. However, the corrosion zone developed gradually from the mid-span of the beam to the two ends, and there was a linear relationship between the extent of the corrosion zone and the corrosion period. Similarly, the degree of pitting corrosion and general corrosion also increased. The relationship between pitting corrosion and general corrosion developed along an improved exponential curve, while the pitting factor and the general corrosion showed a logarithmic relationship. The results of this investigation could be treated as an envelope curve, which can be helpful to assess the corrosion state of reinforcements situated in aggressive environment and predict the residual life-cycle of corroded constructions.