post tensioningi estimating losses in tendond

[samdamon]

Need the latest and greatest methods of estimating friction forces and elongation in unbonded post tensioning systems for parking garage and building slabs, US practice. What are the standard methods for these issues in your office? Can you direct me to a publication or two that has the latest info?

Thank you.

 

[oldhand]

Go to your prestressed concrete design codes. They give factors for wobble and friction. (e.g. BS5400) These parameters do not change much. If you are concerned that modern materials are diferent talk to the manufacurers of the potential systems. Beware that manufacturers give the best their system can do and in construction you may not obtain their low values or the system may be different.

 

[samdamon]

Thanks oldhand, I was able to obtain wobble and friction values from the supplier. Regards