Patent ID: 6623558
Filing Date: 2003-09-23
Classification: C08G,E04C

Abstract:
A sheath-covered tendon for prestressed concrete having a structure that a curable composition is applied to the surface of a tendon for prestressed concrete, and the coated surface thereof is covered with a sheath,wherein the curable composition comprises at least one liquid epoxy resin selected from the group consisting of bisphenol A epoxy resins and bisphenol F epoxy resins and a ketimine compound as a moisture-owing agent, wherein the range of the equivalent number corresponding to the proportion of the moisture-curing agent incorporated is 0.019&lE;P&lE;0.31 in terms of a ratio P of the parts by weight of the moisture-curing agent incorporated to the equivalent parts by weight incorporated, and wherein the tensioning-permitting time L at 90Â° C., which is expressed by the time required until the viscosity of the curable composition as measured at 25Â° C. at the time when the curable composition has been left to stand under environment of 90Â° C. and 60% in relative humidity reaches 10,000 poises, and the number of days M required to cure at normal temperature, which is expressed by days required until the type D Durometer hardness of the curable composition as measured in accordance with JIS K 7215 at the time when the curable composition has been left to stand at 25Â° C. reaches 60, satisfy, the respective relationships represented by the following expressions (1) and (2): L (hours)&gE;20â€ƒâ€ƒ(1) M (days)&lE;1095â€ƒâ€ƒ(2).