Use polythene sheeting if necessary the bay should be long enough to accommodate the longest tendon and the strand dispenser.
From dispenser: pull individual strands from the dispenser to required length.
Extend ram of basket rig to produce the basket – release ram.
Remove wedges and remove strand from rig.
Check the basket diameter.
Installation
Seal duct to anchorage using dens or duct tape. Seal ducting joints using duct tape. Tie dead end to reinforcement.
Install grout vents at the live end and at the dead end ensure that the grout vent height around 300mm above the concrete surface and place a rigid tube or reinforcing bar in the vent to prevent twist during casting
In order to avoid crushing of duct due to designed low space between high points & top reinforcement, additional support to top reinforcement will be provided to avoid sagging of rebar during steel fixing.
Stressing
Work from central strand and outward symmetrically.
Lock off each strand after stressing.
Submit the extension record for approval to consulting engineer prior cutting strands for grouting.
Post-Tensioned Slab Installation For Stressing
-Final Stressing Loads are specified as 75% of the Ultimate Tensile Strength of the 12.7mm Strand.
-This equates to 146kN for the supplied strand
-Only experienced Supervisors will carry out stressing works. A list of which will be issued to the Structural
-Engineer prior to stressing operations commencing
Procedure – Preparation of Live Ends
Procedure- Strand stressing
Strand stressing sequence as specified below should be followed
Confirmation of Elongations and Permits to Cut and Grout Strand
Grouting
Carry out remedial works on vents as necessary.
Stock fresh bagged cement close to mixer Arrange 8Nbr 225 litre drums of suitably chilled potable water close to mixer. ( 5-10C )
Lock off grout inlet pipe and continue with next tendon repeating the same operation.
Quality Assurance
Also check if grout mix appears visually thick.