GB880224A - Improvements in or relating to anchorage devices - Google Patents

Abstract

880,224. Wire anchorage device for prestressed concrete. P.S.C. EQUIPMENT Ltd. July 12, 1960 [July 27, 1959], No. 25676/59. Class 20(4) An anchorage device for a wire or wires in prestressed concrete includes an internally tapered female member 1 having its inner periphery defined by a helically disposed wire 3, and an externally tapered male member 8, Fig. 3, adapted to bear against the helically disposed wire 3, the co-operating areas near the inner narrower ends of the tapered surfaces of the male and female members being arranged to bear upon each other with less force than the force between the remaining co-operating areas thereof when the male member is fully home. In the embodiment of Figs. 1 and 3 the reduction of bearing force is obtained by making the taper of the female member progressively less near the inner narrower end 4 thereof. In another embodiment, Figs. 5 and 6 (not shown) the taper of the male member is made progressively greater near the inner end thereof. The tensioning wire passes through a bore 9 in the male member 8 which is comprised by a plurality of segments, and by means of the invention the gripping effect of the segments on the tensioning wire is relieved gradually and progressively to reduce the tendency towards premature failure of the wire. The female member shown in Fig. 1 comprises a concrete block having helical reinforcement 2 and is provided with a union 5 adapted to receive a corrugated sleeve 6 which surrounds the tensioning wire. A grouting tube 7 leads to the sleeve 6.