Multistrand flat duct - bonded tendon systems

The multistrand flat duct systems is normally adopted for bonded tendon. The strands are individually gripped in one flat anchor head unit and tramsmits their prestressing forces by means of flat type anchor plate casting unit. The strands are stressed individually by means of a mono strand jack. The strands are contained in one flat duct which is made of corrugated galvanized or non-galvanized metal. To ensure corrosion protection and to give adequate bond strength, the tendons are filled with suitable cement grout mix after complete stressing of the strands.

Stressing anchorage data

The same anchorage for stressing anchorage can be used as dead end anchorage in which case the wedges are preseated in the anchor head unit by applying nominal force to the strand using the stressing jack.

Alternatively a bulb dead end anchorage can be used with simpler solution and more cost effective. In this case each strand is formed into a bulb shape by means of special bulb forming jack.

Burstling reinforcement should be provided at the anchorage zone for both stressing anchorage and dead end anchorage type.

Dead end anchorage

1. Bulb dead end 2. P.C. strand 3. Grout vent with mastic seal tape 4. Corrugated metal flat duct 5. Burstling reinforcement

Mono strand stressing jack

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