Unbonded External Post-tensioning

Wide-span bridges and wind towers are strengthened by exterior unbonded post-tensioning systems.

The systems make use of Threadbars, which are tendons with strands and wires.

Systems that have a low range of produced stress and minimal fretting fatigue can be prefabricated or put together on location. The structural durability is enhanced with flexible fillers that provide corrosion protection.

Our post-tensioning tendons are inspectable, replaceable, and may be restressed if necessary. They include strands, wires, and Threadbars. There are solutions for deviations. Additionally, our engineers may set up the stress force monitoring to complement our Infrastructure Intelligence service.

External wires and strands:

External tendons with strands and wires are commonly employed in the pre-stretching of concrete and hybrid wind towers, as well as in bridge construction projects where they are used as longitudinal tendons between bulkheads.

There are options for wire systems with up to 84 wires and strand systems with up to 55 strands.

External mono-strands:

Round tank walls are one special application for exterior mono-strands. The tendons are placed in a closed ring that is either circular or semicircular in shape. A single-strand floating coupler allows for the creation of circular arrangements as well.

External bars:

Increasing the shear capacity of constructions where bar tendons are positioned vertically outside webs—to replace any missing stirrup reinforcement—is an important field of application for bars. Bar systems are offered in diameters up to 47mm.

Features:

Monostrand systems and strand systems with up to 55 strands
Bar systems up to 47 mm in diameter
Systems with up to 84 wires
Flexible fillers that prevent corrosion help ensure the structural stability.
Low range of produced stress
Less worry tiredness
Monitoring of the putting pressure
Possible restressing, if necessary
Ability to be inspected and replaced
Available corrections for deviations
Prefabrication or on-site assembly is an option.