Internal Unbonded Post-tensioning System Using Wire

A durable, cost-effective, and corrosion-resistant solution for longitudinal post-tensioning of bridges.

DYWIDAG’s internal unbonded post-tensioning system using wire is a high-performance solution for longitudinal post-tensioning of bridges and other concrete structures. While internally unbonded longitudinal post-tensioning with monostrands is technically feasible, it often leads to a strong cross-sectional weakening, which must be considered in the shear force design. Therefore, we recommend the use of compact bundles of parallel wires in thick-walled plastic ducts for unbonded longitudinal post-tensioning.

Our system is designed to provide optimal load-carrying capacity and durability, while also being easy to install and maintain. The use of wire in an internal unbonded post-tensioning system results in a lighter structure, reduced corrosion, and improved aesthetics, making it an ideal choice for bridges and other structures where these factors are important considerations.

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

  • Wire diameters of 7mm

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

  • Prefabricated options available for ease of installation, with curved or straight tendon profiles

  • No grouting operations required on site, for faster installation times

  • Wires are inspectable (e.g. warning signs given through the structural behavior) providing good structural monitoring options

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

  • Replacement and restressing available

  • Coupling possible when no replacing/restressing is required

Main standards for steel nuances

Europe/ Asia/ Latin America: Y1670, Y1770

Europe: Z-13.2-109 (Germany)