×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

unbonded precompression ranges

unbonded precompression ranges

unbonded precompression ranges

(OP)
I've been designing unbonded PT condo flat plate slabs with precompression ranges in the 200 to 250 psi ranges as recommended by several references.

Recently a project with large irregular spans (~40') has pushed required precompression to well over 500psi in some spans to get the stresses to work out.  Are these published ranges just for economy or are there other reasons I should keep them down?

Thanks,

RE: unbonded precompression ranges

With greater precompression forces you'll certainly increase the likelihood of blow-outs and increase congestion of rebar/tendons.  You might want to choose a concrete mix design  with higher strength and lower viscosity.  

RE: unbonded precompression ranges

As the precompression increases more attention needs to be given to the effects of restraint on slab shortening and the stresses induced by this.

Logical solutions are varied slab depths and short tendons in critical areas.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources