Abstract
Weathering steel is generating precise rust on the surface, and has the character which controls progress of corrosion. However, protection rust may not generate depending on the placed environment. Therefore, the weathering steel bridge needs to perform check after construction, and needs to evaluate the state of rust. The basic method is to evaluate in five steps from rust appearance of the particle diameters. This is a standard evaluation method used for a long time, but even an expert may hesitate about a judgment because it is not necessarily given a standard quantitative enough. In order to improve these problems, we propose the appearance evaluation method using the image analysis in this study.
