ACI Post Tensioned Long-Term Losses

[PEinVA]

I'm looking at an elongation calculation submittal for a repair job on a PT slab. I've been able to calculate the elongation from the final force obtained and knowing the length, area and Young's modulus of the cable. However, I can't located in ACI or PTI's code where the values for the constants used to calculate the long term losses are obtained. Any help on that?
Thanks.




RC
All that is necessary for the triumph of evil is that good men do nothing.
Edmund Burke

http://www.tbastructures.com

 

[ash060]

The equations for friction loss are in 18.6.2 of ACI 318-02
The commentary has some tables for wobble and curvature coefficients. I have seen typically a 1/4" for sitting losses, and PCI and PTI manauals have some examples of calculating prestress losses