Abstract: A method and apparatus for tensioning concrete reinforcing tendons or the like are disclosed which are particularly well suited for use in the construction of prestressed concrete tanks. The method includes mounting a wedge assembly on the tendon and mounting a wedge assembly housing around the wedge assembly, with the improvement being comprised of the steps of forming a spiral groove of relatively shallow depth in the tendon prior to mounting the wedge assembly thereon, and rotating the housing in a manner similar to a turnbuckle to simultaneously and proportionally induce radial tendon gripping forces in the wedge assembly and substantial axial tension forces in the tendon. The method has the additional advantage of preventing relative slippage between the wedge assembly and tendon even when conventional tendon jacking techniques are employed to tension the tendon.

Abstract: A tendon anchorage for use in prestressing concrete members is disclosed which preferably includes a tubular mounting means mounted to extend over the tendon and through an opening in a bearing or anchor plate in order to secure the bearing plate in fixed and aligned relation to a tendon for casting the bearing plate into the concrete member in a predetermined orientation therein. Spacing means between the form board and the anchor plate allow the anchor plate to be cast into a recess in the concrete member. A wedge receiving housing and wedge assembly is positioned in alignment and in abutting relation with the bearing plate after casting of the bearing plate into the concrete.

Abstract: A method of forming an anchor member for use in a concrete prestressing anchorage is disclosed. The method includes the provision of plate means formed with a bore therethrough, positioning of a tubular conduit means in the bore, and urging of the conduit against the side walls of the bore to radially deform the conduit and bore into a tapered bore suitable for mounting of tendon gripping wedges therein. The urging step not only forms the taper in the bore, but also effects securement of the conduit to the plate. The conduit may be positioned to extend from either or both of the front or rear sides of the plate to provide or enable securement of auxiliary structures to the anchor member, e.g., means for mounting of the anchor member to a form board. The method employing the conduit may be used to effect securement of a plurality of plate-like elements together to form a unitized anchor plate. Anchor members including tubular conduit means press-fit into the tapered bore are also disclosed.

Abstract: A tendon anchorage for use in prestressing concrete members is disclosed which preferably includes a tubular mounting means mounted to extend over the tendon and through an opening in a bearing or anchor plate in order to secure the bearing plate in fixed and aligned relation to a tendon for casting the bearing plate into the concrete member in a predetermined orientation therein. Spacing means between the form board and the anchor plate allow the anchor plate to be cast into a recess in the concrete member. A wedge receiving housing and wedge assembly is positioned in alignment and in abutting relation with the bearing plate after casting of the bearing plate into the concrete.