On basis of inspection of reinforced concrete bridge aged 18 years exposure to chloride salt environment in practice, this paper investigated the deterioration characteristics of typical damaged bridge elements, and both the corrosion rate of rebar and corresponding transportation rules of chloride ion in concrete were analyzed. The variation of amount of alkali and pH value caused by chloride ingress in corresponding concrete are also studied in details. Further, the mechanism of deterioration of concrete and microstructure of corresponding concrete are discussed. Results indicate that rebar can be corroded severely and cracks occur in concrete cover under sodium chloride solution action for a relative short time practically. The transportation velocity of chloride ion is rapid in corresponding concrete under wet and dry circles condition. There exists physical crystallization action of sodium chloride solution in concrete. The ingress of sodium chloride into concrete results in an increase of alkali and a reduction of pH value, which may cause a potential damage of alkali aggregate action.
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