In this study, with the aim of examining the cost reduction effects of each partial repainting and painting method, using a partial repainting coating model created based on the prediction of deterioration of the paint film and the prediction of the corrosion of steel, Life Cycle Cost and the corrosion of steel in the 50 years of service in different partial repainting methods were calculated by examination simulation. A rational partial repainting method was examined by quantitatively evaluating the relationship between them. As a result, a repainting method combining temporary coating and partial repainting, a method using the Rc₋I painting system, and a method of repainting when the rust area is 10% showed no significant increase in the amount of corrosion of steel, and the cost reduction effect was confirmed.
