To largely improve impact resistance by sequentially laminating a polyethylene layer having a spiral protubelance and a protective layer constituted by glass fiber mat, polyester nonwoven fabric or polyester cloth and polyester or urethane elastomer.
A polyethylene layer 4 having a spiral protubelance 5 is laminated via a polyethylene adhesive layer 3 on an outer surface of the steel pipe pile 1 covered with epoxy primer layer 2. Its outer surface is coated with protective layers 6 made of glass fiber mat, polyester nonwoven fabric or polyester cloth and polyester or urethane elastomer. The mixing weight of the glass fiber with total weight of the mat, polyester or urethane elastomer in the layer 6 is 5 to 50 wt.%, and the number of windings of the nonwoven fabric or cloth is once or more, and the thickness of the layer 6 is preferably 1 mm or more.
MIYAJIMA YOSHIHIRO
MIMURA HIROYUKI
SUEUCHI YASUHIRO
SATO HIROTAKA
FUNATSU SHINICHI
OKADA HIROSHI
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