Conical wedge and sleeve anchorage for prestressing wire - uses two-part sleeve with stepped spiral ramp joint which offsets wedge slip by relative rotation of both parts

摘要

The post-tensioning prestressing system uses wedges (5) and a cone-mouth (4) sleeve (2) to anchor single wires (B) or strands, and is designed to compensate for wire extension losses (7) due to the drawing in of wedges (5) at transfer. The sleeve is in the two axial pieces (2a,2b) with complementary stepped spiral ramps (8) on their abutting ends. Once initial stressing is accomplished the loss is made up by applying further tension through one axial piece (2a). The other piece (2b) is then rotated by radial lugs (12) to take up the axial slack. The ramped interfaces (8) may have a saw-tooth profile. The stressing jack may be equipped to effect the two stage stressing and to rotate the axial piece.