Very short precast spandrels with "PRESTRESSING"

[KimWT]

Hi!

I wonder what will happen to pretensioned precast spandrels, whose dimensions are 10ft long (simple span), 8ft tall and 8in thick.
Should I ignore all prestressing forces?
(Like 22 strands with 16kips pullout per each strand.)

Thanks!

 

[IDS]

Why do you think you should ignore the prestress?

How you handle the design would depend on the loading and the support system.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[dik]

You would likely lose a lot of your stressing for such members unless they were cast in a bed and sawcut to length. Can you use regular reinforcing?

Dik

 

[rapt]

Sounds like a deep beam to me.

And a deep beam requires that the bottom steel be fully developed at the end supports. Not sure how you could do this with pre-tensioned strand. You would need bottom reinforcement with development length extending from the end if it is cast in!