Dyckerhoff & Widmann Aktiengesellschaft

Other

Egbert Zimmermann

Oswald Nutzel

Dieter Jungwirth

A corrosion-protected tension member, such as a tendon for prestressed concrete with post-tensioning, is made up of a bundle of individual tension elements, such as strands, arranged within a tubular envelope. The tension member extends between anchoring devices, each forming an anchor region for the tension member with a free region located between the anchor regions. In the free region, the tubular envelope is formed of a sheathing tube. Each individual element is located within a separate sheathing duct, and a corrosion-protection mass fills the space within the ducts about the elements. The open volume within the sheathing tube around the sheathed elements is filled with cement mortar. In the anchor regions, the tubular envelope includes an anchor tube enclosing an anchor pot. The anchor pot has a base with openings through which the individual elements pass in a sealed manner. The anchor pot is filled with a corrosion-protection mass. Accordingly, the individual elements are axially movable and retensionable along their entire lengths. The sheathing ducts and the anchor pot separate the cement mortar from the individual tension elements in the free region extending between the anchor pots.

Corrosion protected tension member for use in prestressed concrete and

In the assembly of a tension tie member between spaced anchors when the tie member is made up of a number of individual tension elements, such as steel wires, steel strands or the like, enclosed within a tubular sheathing, the tension elements are inserted individually and successively between the anchors and it is necessary to insert the annular wedges which anchor each element before the tension elements are released from a threading device. To prevent the annular wedges from prematurely entering into the boreholes in the anchor plate, an auxiliary plate is positioned spaced from the anchor plate. The auxiliary plate has at least one through borehole axially alignable with the boreholes in the anchor plate. A tubular section is secured to the auxiliary plate and forms an extension of the borehole therein. An annular wedge to be inserted into one of the boreholes and the anchor plate can be held on the tubular section by resiliently expanding the wedge about the outer surface of the tubular section. An individual tension element can be inserted through the auxiliary plate and then through the anchor plate and the tubular sheathing and finally through the other anchor plate without any interference from the annular wedge. After the tension element is completely inserted, the wedge can be slipped off the tubular section and inserted into the borehole in the anchor plate by means of a simple handle.

Apparatus for and method of assembling a tension tie member

A tension tie member is anchored between two spaced locations on a structure, such as a diagonal cable in a stayed girder bridge. The tie member is supported on the structure adjacent at least one anchor location by an annular bearing member encircling an outer protective casing of the tie member. The bearing member is positioned within an annular chamber in the structure at the point where the tie member extends through the structure toward the anchor location. The diameter of the annular chamber is larger than the diameter of the tie member so that there is a certain amount of play between the bearing member encircling the tie member and the surface of the annular chamber whereby lateral movement of the tie member can occur. With the tie member anchored in place the space between the outside of the bearing member and the inside surface of the annular chamber can be filled with grout to support the tie member.

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Oberaudorf, Germany

Egbert Zimmermann