GB1020432A - An improved anchorage device for the prestressing elements of reinforced concrete - Google Patents

Abstract

1,020,432. Cable attachments. SOC TECHNIQUE POUR L'UTILISATION DE LA PRECONTRAINTE. Sept. 28, 1962 [Oct. 4, 1961], No. 36861/62. Heading D1T. [Also in Division E1 and E2] An anchorage device for a plurality of substantially parallelly arranged prestressing elements in the form of individual wires, rods or wire-ropes, comprises a female part 1 having a tapered aperture la through which the elements are adapted to extend from each end thereof and a plug 2 having a tapered external surface adapted to wedge in the aperture 1a of the female part, there being provided in the plug a coaxial passage adapted for reception therethrough of the elements and there being further provided at least one non- annular division member 4 insertable in the passage in the plug, the plug and division member or members being independently movable axially of the aperture in the female part and the arrangement being such that after tensioning the elements by means acting to draw the same through the aperture in the female part in one direction, the plug is movable jointly with the division member or members into the aperture in the female part in the other direction thereby to clamp and hold the tensioned elements in the aperture of the female part so that each element is engaged at least by a surface of the plug or of the, or one of the, division members. In the construction shown in Fig. 1 which is for use with wires or rods, two division members are used each of which is serrated on both sides and the plug which is in two parts is also internally serrated so that each wire or rod is engaged by two serrated surfaces. Two forms of serration are described, one in which the surfaces of the serration are symmetrical and the other in which they are asymmetrical. Each division member has two lugs 4a so that the member bears on the female part 1 and remains fixed in position while the plug is driven into place. In a modification of this construction the division members bear on the plug so that they move with the plug; this construction is used both with wires or rods and with wire ropes. Constructions are described for gripping numerous different numbers of elements from three up to twenty-seven and using from one to six division members and with the plug having from two to six parts. In the majority of the constructions the tapering cavity in the female part is frusto-conical in shape but in one construction this is modified so that the cavity has flat portions joined by curved portions and the plug is similarly modified.