Post-Tension Avg. precompression limits 1

[DNaimat]

Can anyone tell me if there is a reference in the ACI code that specifies that the maximum limit of precompression force in a post tensioned slab is 300 Psi (2 Mpa)???

 

[KootK]

Link

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[rscassar]

DNaimat

I have specified over the 300psi several times. Unfortunately I cannot provide a code reference.

 

[rapt]

Higher levels of compression are allowed. There is no code limit.

But the designer must consider the effect of restraint in the strength and serviceability calculations. This will all depend on the level of restraint to shortening and even the construction sequence and allowance for pour strips to all some movement. Shrinkage and creep effects and temperature change should all be considered as well.

None of the computer software for PT slab design currently considers this fully.