Dyckerhoff & Widmann Aktiengesellschaft

Alto Mannhart

Dieter Jungwirth

Johann Wlodkowski

Lorenz Schnitzler

Georg Rieger

A method of tensioning parallel prestressing members of a building or building component of prestressed concrete or a tension member composed of a plurality of individual elements, such as steel rods, steel wires or steel strands, wherein the individual elements are successively tensioned either individually or in groups. The tensioning method described above includes the steps of tensioning a first individual element or a group of individual elements until a predetermined tension is reached and anchoring the first individual element or group of individual elements; tensioning a second individual element or a group of individual elements until the tension thereof is equal to the tension of the previously tensioned individual element or elements at the same time and anchoring the second individual element or group of individual elements; and repeating the preceding step until all individual elements are tensioned and anchored.

Method of tensioning a tension member composed of a plurality of

A method and a device for cleaning and exposing portions of limited length of strands of steel wire which are surrounded by a corrosion protection substance, particularly grease, wherein the strands of steel wire and the corrosion protection substance are enclosed by a sheathing of synthetic material. Initially, the sheathing is severed at a distance from the end of the strand corresponding to the length of the portion to be cleaned and an opening is produced. Subsequently, a flushing pipe is connected to the sheathing at the end of the strand and the strand is cleaned by admitting a flushing liquid under high pressure into the space surrounded by the sheathing, so that the corrosion protection substance and the flushing liquid emerge at the opening. Finally, the sheathing is removed entirely from the strand by pulling off the sheathing.

Method of cleaning and exposing portions of limited length of strands of

A device for securing a sleeve on the abutting ends of two axially aligned reinforcing bars includes an upper device part, a lower device part aligned below the upper device part and a drawing die mounted on the lower device part. Cylinder-piston units interconnect the upper and lower device parts for moving the drawing die over the sleeve and coupling the reinforcing bars together. The cylinder-piston units are disposed in parallel relation to one another and to the axis of the drawing die. At least one cylinder-piston unit provides the drawing force and another provides a counteracting force. The cylinder-piston units are both located on the same side of the drawing device axis and are spaced at different distances from the drawing die axis.

Device for securing a sleeve on the abutting ends of reinforcing bars

To form a radially outwardly extending bulge in a steel wire strand made up of a plurality of individual wires, the strand is compressed along an axial length so that the individual wires deform radially outwardly and in spaced relation to one another. Compressive force is applied to one end of the strand and the strand is anchored at an axially spaced location from the end. A tubular member with a cylindrically shaped inside surface forms a limiting boundary for the outward movement of the individual wires. The tubular member is located between the end of the strand and the location where it is anchored. The end of the strand and the tubular member are rotatably supported. Each individual wire extends along an angular path about the axis of the strand between the end of the strand and the anchor location.

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Munchen, Germany

Alto Mannhart