DETERIORATION OF COATING FILM ON STEEL RAILWAY BRIDGE AND SALT REMOVAL BY BASE PREPARATION DURING REPAINTING

Abstract

 The state of deterioration of the coating film on steel railway bridges is determined by evaluating the state of the coating film during periodic inspections and using the scores corresponding to the evaluation. We analyzed the relationship between the time after repainting at each steel railway bridge in the jurisdiction and the score.As a result, it was found that the steel railway bridges located in the "coastal area" tend to deteriorate quickly and the deterioration of the coating film tends to be quicker on railway bridges built in older years.In addition, we focused on the amount of salt adhering to steel railway bridges, which is thought to have a significant effect on the deterioration of the coating film, and measured the removal of salt in each part during surface preparation (blasting + water washing) during repainting. After surface preparation, the amount of adhered salt was less than 50 mg/m² overall, but it was about 100 mg/m² in congested parts and gaps of members.