External Unbonded Post-tensioning System Using Wire

DYWIDAG’s external unbonded post-tensioning system with wire is designed for use in a range of different applications, including bridge construction and the prestressing of wind farms with concrete and hybrid towers. One of the key features of this system is its use of external tendons with wires, which are specially designed to provide optimal strength and durability. The wire tendons can be easily adapted to a variety of different configurations and arrangements, making them ideal for a wide range of different applications.

The system also features a range of advanced deviation options, and is engineered to provide extremely small deviations, making it ideal for use in structures where precise tolerances are required. Standard deviation is set up through the use of deviation half-shells, while cast-in and bent ducts can be used for special applications. The system also allows for bi-axial deviations through the use of deviation half-shells, and an intended deviation angle of up to 2 x 10° is possible. Additionally, the deviation half-shells provide an allowance angle of 3° in each direction for unintended deviations. The minimum deviation radii depend on the tendon size and steel grade, which can be found in the accompanying table.

To ensure optimal performance and durability over the life of the structure, this external unbonded post-tensioning system with wire is designed to provide exceptional corrosion protection using PE sheathing and a corrosion protection compound. There is also the option for complete prefabrication of the corrosion-protected tendon up to a length of 400 m, for easier and quicker installation.

The wire tendons are also infinitely re-stressable, which enables the system to maintain the original level of prestressing force, despite various external forces. This can help to ensure that the structure maintains its original design capacity and is able to resist external loads and forces as intended, even over the long term. Additionally, the ability to re-stress tendons infinitely can also help to extend the service life of the structure, as it allows for ongoing maintenance and adjustment of the prestressing force to compensate for any changes that occur over time.

  • Available for use with between 30 and 84 wires for increased load capacity and greater durability

  • Wire diameters 7mm

  • Low slip anchorages for low losses of pre-stressing force

  • Wires are inspectable, providing good structural monitoring options

  • Tendon profile is a sectional straight line with deviation, if applicable

  • Extremely small deviations possible for structures where precise tolerances are required; deviation half-shells provide easy tendon installation, even with biaxial deviation

  • No grouting operations required on site, for faster installation

  • Complete prefabrication of the corrosion protected tendon up to a length of 400m is available for faster and quicker installation

  • Stress measurement with DYNA Force® possible to ensure ongoing performance and safety

  • Infinitely re-stressable for ongoing maintenance and extended service life

  • PE sheathing and corrosion protection compound provided to provide optimal protection against a wide range of potential damage mechanisms

  • Replacement, re-stressing and coupling possible

Main standards for steel nuances

Europe/ Asia/ Latin America: Y1670, Y1770

Europe/ Asia/ Latin America: ETA-07/0186