Method and apparatus for inserting post-stressing tendons in concrete structures
AssigneeSociete Technique pour l'Utilisation de la Precontrainte
InventorJohn Terence Crawford Harvey
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Abstract
In the post-stressing of concrete structures, a tendon comprised of a plurality of elongated strands is formed by inserting elongated strands which will eventually form the tendon into a plurality of parking ducts and then withdrawing the plurality of strands simultaneously as a group from the parking ducts and into the duct of the structure to be post-stressed without fouling and jamming. Once in the ducts of the structure, the strands are anchored and post-tensioned as a tendon to develop the desired stress.
Claims11
In the post-stressing of concrete structures, a method of inserting a post-stressing tendon into a duct in the structure which comprises providing at least two elongate parking ducts externally of the duct in the concrete structure, inserting at least one tendon strand into one of the elongate parking ducts to house the strand along at least a substantial portion of its length, inserting at least one further strand into anOther of the parking ducts to house the strand along at least a substantial portion of its length, and drawing all of said strands as a group simultaneously from the respective parking ducts into the duct in the structure.
Apparatus for inserting a post stressing tendon into a duct in a concrete structure comprising a sheaf of open ended, elongate parking tubes, each tube having a length sufficient to receive at least a substantial portion of one tendon strand, means for feeding successive lengths of strand from a supply coil to each of said parking tubes, means for severing successive lengths of strand from the supply coil, and means for drawing all of said strands as a group simultaneously from said parking tubes and into a common duct in a concrete structure to form a tendon therein.
Dependencies are inferred from the claim text.