×
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

PT Tendon Bundles in Transfer Girders

PT Tendon Bundles in Transfer Girders

PT Tendon Bundles in Transfer Girders

(OP)
We are currently designing some long span transfer girders that require a significant amount of 1/2" unbonded tendons. We typically use rectangular tendon bundles that are six tendons wide, and this results in a large number of bundles. Is there a maximum number of tendons per bundle? Is there a minimum spacing between bundles? Thank you.

RE: PT Tendon Bundles in Transfer Girders

See sections C and D of page five:Link. No hard maximum on number of tendons but some limits on bundle spacing.

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.

RE: PT Tendon Bundles in Transfer Girders

Use Bonded Multistrand tendons!

RE: PT Tendon Bundles in Transfer Girders

The link which KootK posted says that in practice, the limit is 6 strands/bundle. Like rapt, I don't know why you would stick with unbonded tendons...ever, but especially for transfer girders.

RE: PT Tendon Bundles in Transfer Girders

Hokie,

I should have expanded on this initially.

I agree, never use un-bonded tendons in transfer girders. The whole building is relying on the friction grip in the anchorages for the life of the structure.

RE: PT Tendon Bundles in Transfer Girders

Even in wayard north america, we'll grout our transfer beam tendons sometimes, just because the stakes are so high.

While I'm usually not one to hang my hat on this argument, we've done a lot of unbonded PT transfer beams and the track record indicates satisfactory performance. Usually a PT transfer beam will have a lot of tendons and a lot of anchorages. A friction grip failure in one isn't a big deal. A friction grip failure in several won't bring the building down and may well provide the warning that folks need to identify the problem. So, unless there's some reason to think that all of the anchors might go at once, the reliability aspect of this bothers me not at all.

Rogue corrosion issues would concern me more. I've done some main floor, perimeter PT transfer girders adjacent to traffic. Indoors... but adjacent to traffic. Hopefully the building envelope guys were up to snuff.

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.

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