Post Tensioning System For Slab

The systems are primary designed to suit for the post tension slabs and shallow depth structures such as in the transverse post tension of bridge deck slab and most of building slabs. The systems are available for both unbonded and bonded tendon systems.

Multistrand Flat Duct – Bonded Tendon Systems

The multistrand flat duct system is normally adapted for bonded tendon. The strands are individually gripped in one flat anchor head unit and transmit their prestressing forces by means of flat type anchor plate casting unit. The strands are stressed individually by means of mono strand jack. The strands are contained in one flat duct which is made of corrugated galvanised or non-galvanised 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.


Anchorage components

  • 1. POCKET FORMER
  • 2. WEDGES
  • 3. ANCHOR HEAD TYPE SF
  • 4. ANCHOR PLATE CASTING TYPE SF
  • 5. GROUT VENT
  • 6. CORRUGATED METAL FLAT DUCT
  • 7. ANCHORAGE BURSTING REINFORCEMENT



Stressing Anchorage Data

Stressing anchorage data

Strand Dia. 0.5”      (12.7mm.) 0.6”      (15.2mm.)
Tendon Type
305 405 505
206 306 406
No. Of Strand
3 4 5
2 3 4
Anchor Head Type
SF305 SF 405 SF 505
SF206 SF306 SF406
Anchor Plate Casting Type
SF305/206 SF SF505/40
SF305/20 SF SF505/406
Ultimate Tensile Force Per Tendon, (kN)
558 744 930
558 837 1,116
Stressing Force at 0.8 U.T.S.,
446 595 744
446 670 892
Flat Duct inside Dimension
63.5X20 63.5X20 76.5X20
63.5X20 63.5X20 76.5X20
Jack Type
V16 V16 V16
V24 V24 V24



Dead End Anchorage

A bulb anchorage can be used as a dead end anchorage 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. Bursting reinforcement should be provided at the anchorage zone for both stressing anchorage and dead end anchorage type.

Loop dead end anchorage for unbonded tendon
  • 1. BULB DEAD END
  • 2. PC STRAND
  • 3. GROUT VENT WITH MASTIC SEAL TAPE
  • 4. CORRUGATED METAL FLAT DUCT
  • 5. BURSTING REINFORCEMENT