There was report issued about 11 years ago in New Zealand
following some research on the bending of rebar. It found that one
(1) cold bend of rebar resulted in minimal loss of strength, however, on
two (2) or bends there was a drastic loss of strength. I therefore
only allow one cold bend, however, what I don't see .... Heating
and bending is definitely out!
Hence you need to exercise caution
with on-site bending.
Thor A Tandy P.Eng Victoria
BC Canada e-mail: vicpeng(--nospam--at)sprint.ca -----
Original Message ----- From: Jim Persing To: SEAINT
Sent: Friday, July 06, 2001 11:30 PM Subject: Bending
Embedded Reinforcing Steel
I have a detail on my plans
with #4 bars bent 90 degrees from vertical in a concrete stem
wall to horizontal into a slab on grade. Nothing unusual.
The contractor wants to install embedded bars in the stem wall with
the 90 degree bend to horizontal and then another 90 degree
bend back to the vertical just outside of the stem wall to make
kind of a vertical Zee. This last bend is temporary and will
be bent back to horizontal when the slab is
placed. I have an older CRSI book which allows it only
with the approval of the engineer and also a CRSI Engineering
Data Report Number 12 which seems to indicate that it is probably
OK for smaller bars.
I can think of lots of reasons why this
should not be done but just wonder if anyone else has had this
detail presented to them and whether or not they approved it