The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 10, 1985
Filed:
Sep. 01, 1983
Toshiyuki Kitta, Omiya, JP;
Wataru Abe, Hiratsuka, JP;
Japanese National Railways, Tokyo, JP;
Oiles Industry Co., Ltd., Tokyo, JP;
Abstract
A metallic sheath for a posttensioning method wherein an outer peripheral surface or outer and inner peripheral surfaces thereof is (or are) coated with phosphate layer (or layers) and plastic resin layer (or layers) thereupon and preferably further coated with a solid lubricating layer upon the inner peripheral surface of the sheath. The phosphate layer of the outer peripheral surface protect the metallic sheath from corrosion by negative ion within concrete, while, on the other hand, that of the inner peripheral surface prevents the electrochemical corrosion between the inner peripheral surface of the sheath and tendon. Moreover, if a solid lubricating, layer is provided at the inner peripheral surface of the sheath, the sliding friction between the metallic sheath and tendon can be decreased so that prestressed force can be increased as much.