DYWIDAG Prestressing Systems using Bars

Unbonded and external bar tendons are installed either inside or outside the cross section of the structure. Various corrosion protection systems are available, none of which bond with the structure. The tendons may be restressed at any time and, depending on the tendon type, they can also be removed or exchanged.
Internal unbonded and external tendons are intended for use in concrete, composite, steel, timber and masonry structures.
The corrosion protection of unbonded and external tendons depends on environmental conditions and service time.

Bar tendons with free tendon duct, permanent corrosion protection executed during grouting before stressing, design square and rectangular solid plates

Bar tendons with free tendon duct, permanent corrosion protection executed by heatshrinking sleeve, design square and rectangular solid plate
Overview of corrosion protection systems
Tendon with free tendon duct | Tendon without free tendon duct | ||||||
---|---|---|---|---|---|---|---|
Corrosion protection for | Temporary corrosion protection ≤ 3 years | Permanent corrosion protection | Permanent corrosion protection | ||||
Threadbar Plain bar | coating | grouting with cement grout before stressing (installation) | grouting with cement grout after stressing | heatshrinking sleeve or corrosion protection tape | corrosion protection compound | heatshrinking sleeve or corrosion protection tape | corrosion protection compound |
Threadbar Plain bar | coating acc. to EN ISO 12944-5 with protection tube (PE) | cement grout with protection tube (PE or steel) | cement grout with protection tube (PE or steel) | heatshrinking sleeve or corrosion protection tape with protection tube (PE or steel) | protection tube (PE), void grout with corrosion protection compound | heatshrinking sleeve or corrosion protection tape with protection tube (PE or steel) | corrosion protection tape with protection tube (PE) |
Anchorage, range of connection tube | corrosion protection compound or tape | sealing ring plus corrosion protection compound tape | sealing ring plus grout | sealing ring or heatshrinking sleeve plus corrosion protection compound or tape | sealing ring or heatshrinking sleeve plus corrosion protection compound | sealing ring or heatshrinking sleeve plus corrosion protection compound or tape | sealing ring or heatshrinking sleeve plus corrosion protection compound |
Anchorage, range of anchor nut | corrosion protection compound or tape | corrosion protection compound or tape or grout | corrosion protection compound or tape or grout | corrosion protection compound or tape | corrosion protection compound | corrosion protection compound or tape | corrosion protection compound |
Anchorage, range of anchor nut | cap, PE or steel | cap, PE or steel | cap, PE or steel | ||||
Coupler | heatshrinking sleeve | tubes (PE or steel) with transition pieces, sealed with heatshrinking sleeve or tape, filled with corrosion protection compound or tape or grout | tube with transition pieces, filled with corrosion protection compound |