| 摘要 |
PROBLEM TO BE SOLVED: To enhance the long-term adhesive properties of a coated layer in brine by specifying the density and the residual stress of a corrosion-resistant polyethylene layer to be applied on at least, one of the faces of a primer-coated sheet pile through a modified polyolefin layer. SOLUTION: This heavily corrosion-resistant coated sheet pile comprises a sheet pile 1, a primer-coated layer 2, a modified polyethylene layer 3, a corrosion-resistant polyethylene layer 4 and an end part sealing layer 5. The polyethylene resin of the corrosion-resistant polyethylene layer 4 is a noncrosslinked polyethylene and has 0.940 g/cm<3> or more density. The sheet pile 1 having the corrosion-resistant layer 4 of high-density polyethylene shows at least, 30 kgf/cm<2> or more coating residual stress and, in most of the cases, 40 kgf/cm<2> or more, when coated by a routine coating method. Therefore, it is possible to reduce the residual stress of the coating by setting the Vicat softening point of the modified polyethylene layer 3 as an adhesive layer within the range of for example, 50-90 deg.C. Thus the residual stress of the coating is below 20 kgf/cm<2> . |
