Unbonded Internal Post-Tensioning

Bridge maintenance and inspection is made easy with DYWIDAG unbonded internal post-tensioning. 

DYWIDAG unbonded internal post-tensioning systems are strong, reliable, and corrosion-proof. Systems can use mono-strand tendons, wire tendons, strand tendons, and DYWIDAG Threadbars™.

Unbonded internal post-tensioning systems are used as

  • Mono-strand tendons: Bundled, greased, and PE-sheathed mono-strand tendons are typically applied in the construction of buildings—and used in the transversal post-tensioning of bridges

  • Internal wire tendons: Typical applications for internal wire tendons include bridges and other civil structures that consist of solid cross-sections, or slabs where there is a need to check the stressing level at a later stage

  • Unbonded strand tendons: Typical applications for unbonded strand tendons include bridges and civil structures.

  • DYWIDAG Threadbar™: Unbonded internal bar post-tensioning systems are used in projects where infrastructure needs strengthening and repair. Typical applications include the connection between precast members, the fixation or tieback anchorages of steel structures—and transversal post-tensioning.  

Strand systems up to 55 strands and monostrand systems

Bar systems up to diameters 47mm

Wires systems up to 84 wires

Corrosion protection is usually prefabricated with the tendon, delivered to site, and installed 

Soft corrosion-protection compound such as grease, wax, or gel

Low induced stress range 

Less fretting fatigue 

Monitoring of stressing forces 

Restressing possible, if required 

Replaceable, if required