13th German-Japanese Bridge Symposium
Osaka, Japan, August 2023
GJBS
CORROSION ASSESSMENT OF WEATHERING
STEEL BRIDGES IN OSAKA AND WAKAYAMA
PREFECTURES (JAPAN)
Wint Thandar*1, Shen Hui2, Tetsuya Iida3, Nobuto Okubo4,
Yasuo Hanako5, Yasuo Kitane6, Kunitomo Sugiura7
1Advanced
Material Research Center, Public Works Research Institute, Japan.
2JIP Techno Science Co., Ltd., Osaka, Japan.
3Takigami Steel Construction Co., Ltd., Nagoya, Japan.
4,5Takadakiko Co., Ltd., Japan.
6Department of Civil & Earth Resources Eng., Kyoto Uni., Japan.
7Department of Urban Management Eng., Kyoto Uni., Japan.
*contact: thandar-w177cn@pwri.go.jp
Weathering steel are widely used in infrastructure construction on account of its superior corrosion resistance
which makes economically benefit due to reducing repainting costs which is usually essential for the ordinary steel.
The weathering steel, also known as self-protective steel, prevents material from further corrosion by generating
a dense, hard patina when the material reacts electrochemically with water, oxygen and airborne salts. In Japan,
weathering steel bridges account for 80% of the bridges built in the last 25 years. Accordingly, it is important to
understand the corrosion condition and mechanical properties of corroded weathering steel bridges after a longterm service. In this study, the protectiveness of rust layer and evaluation on mechanical properties of four
weathering steel bridges located in Osaka and Wakayama Prefectures are investigated. The performances of
inspected weathering steel bridges are discussed according to the results of rust layer composition by XRD
analysis, protective ability index (PAI), transparent adhesive tape test and hardness measurement.
Key words: weathering steel bridges, rust composition, PAI index, hardness of rust layer