Application of the post tensioning anchor
• Post tensioning anchor can be used efficiently in all applications of building and civil engineering works including highway bridge, railway bridge, urban interchange, urban light rail, high-rise building and so on.
• The strands are individually gripped in one anchorage unit and transmits their prestressing force by means of anchor plate casting unit type M.
• For each type of anchor, a special spiral reinforcement is provided at the casting anchor plate to give adequate splitting reinforcement for burstling stresses developed at the anchorage area.
• The strands in tendon are stressed simultaneously by means of a multi strand stressing jack from capacity 1,100 KN up to 5,000 KN. In case of small size tendon unit such as type M405 the strands can also be stressed individually by means of mono jack.
• 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.
Anchorage in Prestressed Concrete
Post tensioning anchor is a component of post tensioning system used to anchor tendons into concrete when two tendons are terminated or joined. The main function of the anchor is to transfer the stress to the concrete after the stress process is completed.
It is one of the most important 5 components of post tensioning systems. Anchorage is an inevitable part of prestressing system. Efficiency of anchorages affects the service life of a prestressed structure.
Components of Post Tensioning Anchor.
The components of anchor include anchor plate, anchor head, removable grouting cap, iron block/force transfer unit, bursting reinforcement, deviation cone and duct coupler. The prestressing force is applied to the strands and locked in place by the wedges in the anchor head which is supported on the force transfer unit cast into the concrete.
The force transfer unit ensures the transmission of the prestressing force into the concrete. The force transfer unit and the deviation cone ensure the correct deviation of the strands from the anchor head to the duct.
Parameter for post tensioning anchor
According to the diameter of PC strand can be divided into YM12.7, YM13, YM18 type anchor, the anchoring system is mainly applicable to the strength of 1860MPA-2000Mpa and below the level of 12.7mm, 12.9mm, 15.24mm, 15.7mm, and 17.8mm as the standard strength of steel strand of 5mm-7mm high strength steel beam 1670Mpa. Wide range of options, YM is suitable for design of tension anchor system between 0-12000KN, the number of steel strand range is 55.
Post tensioning anchor Including the M series steel wire tension and anchor system: M13 (anchorage for 12.7-12.9mm steel strand and anchorage (M15) used in 15.2-15.7mm steel wire) with YCW series Jack and ZB4-500 type electric pump for tension; for flat structure BM13 and BM15 flat anchor for cyclic stress; the structure of the HM13 and HM15 ring anchor.