PURPOSE: To improve the corrosion resistance and the rustproofing property by providing a thick molten zinc plating layer on a suspension bridge cable use steel strand, and thereafter, providing a chemical conversion treatment layer, and also providing a composite layer consisting of an acryl compound resin and SiO2.
CONSTITUTION: A suspension bridge cable use steel strand 1 whose tensile strength is ≥160kg/mm2 is coated with a molten zinc compound plating 2 whose METSUKE (Japanese syllabary) quantity is ≥300g/m2. Subsequently, a compara tively thin chemical conversion treatment layer 3 by a chromating treatment, a phosphate treatment, etc. is provided on said plating. Also, it is covered with a composite layer 4 whose METSUKE quantity is 2W8g/m2, whose main components are 60W90wt% acryl compound organic synthetic resin portion and 10W40% SiO2 portion, by an immersing method, etc. As for this rustproofing covered suspension bridge cable use steel wire, the covered layer does not fall off in the course of installing work, and the adhesive strength of the rust- proofing covering is excellent.
KAYANE MICHIO
YOKOYAMA KUNIHIKO
