GB819828A - Improvements in anchorage devices for pre-stress reinforcement members - Google Patents

Abstract

819,828. Prestressed reinforced concrete. SOC. TECHNIQUE POUR L'UTILISATION DE LA PRECONTRAINTE S.T.U.P. PROCEDES FREYSSINET. Jan. 23, 1957 [Feb. 9, 1956], No. 2491/57. Class 20(4) [Also in Group XXV] An anchorage device for a bundle formed by a predetermined number of wires in a frusto-conical cavity is constituted by a number of keys equal to that of the wires and in the form of at least longitudinally tapered wedges, each of which is positioned between two adjacent wires, the keys being carried on the periphery of a deformable frusto-conical body and two adjacent keys carried by the body providing an outwardly-flared wire housing at the periphery of the body, in which housing each wire can pass only partly in order that the wires do not contact the bottom of the housing and project beyond the external face of the keys. As shown, wedges 1, preferably of steel are carried on a deformable frustum 2 of a cone which may be of rubber and wires 5 of a bundle to be anchored are engaged between the wedges and project partially from therebetween into engagement with the inner frusto-conical surface 8 of a member 4. The wedges are partially embedded in the frustum 2 as shown or where the frustum 2 is constituted by a thin tube, Fig. 7 (not shown) may be attached to the tube by welding. In another arrangement, Figs. 8 and 9 (not shown) the wedges are formed integrally with the frustum which may be a casting or stamping, of a metal having a high elastic limit and capable of withstanding substantial plastic deformation before fracture. The outer member 4 may be formed from a solid metal block or in an alternative construction, Fig. 6 (not shown) may comprise a tubular casing, an inner metal jacket and a filling of concrete. The frustum 2 may be constructed of cement mortar which is sufficiently deformable to allow relatively small displacement of the wedges. In the arrangement shown in Fig. 4, not shown, some of the wedges may be slidable along the frustum. The wedges may be grooved or corrugated. Specification 657,738 is referred to.