Shingo SAITO

A Study of Quantification of Rust Evaluation of Weathering Steel Bridges

Eiji IWASAKI and Masatsugu NAGAI

Evaluation method based on external of rust is known as a typical method in evaluating rust state of Weathering Steel Bridges. This method is evaluated by the size of the rust particle and the tone of rust. However it is difficult to judge them by using this method because the judgment of external of rust also belongs to humanity cause.
In this study, the quantification of criterion factor of this evaluation method based on field investigation of existing Weathering Steel Bridges in Niigata, as well as the relationship between corrosion environment and rust state are carried out. As the result, objective estimation technique of evaluation level is proposed.
The result of obtaining is described as follows.
1)The chroma and the hue angle tend to be large in the part where the corrosion environment is severe.
2)A strong correlation was not recognized between an individual evaluation factor and the external evaluation level that was the rust external criterion.
3)It was able to propose objective estimation technique of external evaluation level that used the hierarchical neural network.