GB894240A - Improvements in anchorage devices for prestressing reinforcements - Google Patents

Abstract

894,240. Reinforced concrete. SOC TECHNIQUE POUR L'UTILIZATION DE LA PROCONTRAINTE. May 25, 1960 [June 25, 1959], No. 18446/60. Class 20(4) [Also in Group XXV] An anchorage block 1 for anchoring prestressed reinforcements in concrete comprises a hollow frusto-conical part 1a of increasing wall thickness towards its larger end and an integral ring 1b surrounding the larger end of the part 1a. The ring tapers in thickness towards its periphery. The reinforcements may comprise a bundle of wires 4, Fig. 4, forced against the inner surface of the block by a deformable cone 5 with rigid wedges 5a at its periphery for location between the wires, or by a reinforced concrete cone or a steel cone with a grooved outer surface. In another form, Fig. 6, a reinforcing bar 10 is held in the block by wedges 11 having circular or helical teeth 12 on their inner surfaces. The anchorage block may be embedded in the concrete 6, Figs. 4, 6, or placed against the outside of the structure to be reinforced, in which case it is embedded in a concrete block 14 with a tubular steel reinforcement 15, Fig. 9. The bearing surface 13 of the block 14 may be normal to the axis of the anchorage block or inclined as shown. The reinforcement is insulated from the concrete 6 by a tube 9 to allow for post-tensioning.