Working Sequence

The Post Tensioning Working Sequence can be broken down into laying, stressing and grouting as depicted in the below image:

Completion of formwork as per shop drawing.
Check level difference; pour strip location, slab thickness and drop panel depth before erection of bottom reinforcement.
Completion of bottom reinforcement with appropriate Dia of bar and with equal spacing.
Fixing the block out to casting and wrapping it with OPP tape.
Marking of tendon in both live and dead end with marker.
Anchorage should be fixed to the mark at end form work by supporting bars.
Laying of GI duct is under progress.
Fixing of duct to end anchorage with the help of vent coupler and it should be wrapped with OPP tape to avoid entry of foreign particles.
De – coiling of HT Strand and cutting the strand for required size of the tendon.
Inserting the strands to the duct.
Check C.G of the casting.
Bursting reinforcement should be fixed to position at end anchorage.
Profile chair should be fixed to the tendon as per shop drawing.
Fixing of grout hose in both live and dead end. If the span is more than 35m intermediate vent hose should be provided.
Proper packing of casting to avoid entry of foreign particle.
Pouring of concrete (M-45 Grade).
Proper vibration of the member @ face of the anchorage.

Stress the strand for final loading as per stressing calculation report.
Ensure Protruding strand length is sufficient for stressing (350 – 400mm)
Stress of tendon is done by (T-25 Jack) as it can stress only one strand at a time.
Elongation for each strand should be checked after 24hrs.