Study on Appearance Evaluation of Weathering Steel Bridges by a Three-Dimensional Photograph Measurement

A rust state has an important effect on the service life of weathering steel bridges. In this paper, the surface roughness of weathering steel is quantitatively evaluated by using three-dimensional photograph measurement. The effects of the illuminance in the laboratory and distance between the camera lens and the samples on the measure results are investigated. The present results are also compared with those obtained by the other methods. Furthermore, present method was applied to the existing weathering steel bridges.