Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Rebar Spacers in PC beams

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Glen Underwood wrote:

"I've designed a conventionally reinforced precast beam with two layers
longitudinal tension reinforcement - specifically - 8 - #7's in two
of 4 each.  The design clear spacing between the two layers is 1".  The 
beam is 12" x 13" and will be a composite tee-beam when the slab is cast

The production crew has achieved the 1" clear spacing by placing a short

stub of #8 bar between the two layers of longitudinal steel.  This
every 5 feet or so along the beam length."

This is fairly standard.  And yes, it may initiate some cracks, but with
that much steel in the bottom of a small (at least before they put the
slab on) beam, you're going to get significant shrinkage cracking before
any load gets on it.  This cracking will concentrate at these spacers,
but it's going to happen somewhere else if they're not there.  I
wouldn't worry about it.

Mike Hemstad
St. Paul, Minnesota

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at:
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*   Questions to seaint-ad(--nospam--at) Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: 
******* ****** ****** ****** ******* ****** ****** ********