Zinc-aluminum metal spraying method for steel bridges

A method for spraying zinc-aluminum metal has been developed to minimize the life cycle cost of steel bridges. The Fukuoka Expressway No. 5 project, owned by the Fukuoka-Kitakyushu Expressway Public Corporation (FKD), has decided to apply this zinc-aluminum metal spraying method instead of the normal painting system. Kure Shingu Works performed the metal spraying treatment for this project, and a total of 11 000 m2 of metal spraying was successfully completed. In this paper, the results of the adhesion test, which was executed to decide the type of metal spraying method, and the development of automatic spraying machine, are described. The problem and its improvement clarified through this project are discussed.