[TheForge] J Bolts (off topic)

[Ed F]

> J Bolts are used to secure steel fabrication to concrete because they fail
by
> "unbending" . This can usually be detected before a catastrophic failure
occurs
> and thus are massive head injuries avoided.

Hmm, I never heard that line of thought.  I suppose if it didn't completely
unbend it would be very noticeable as compared to an elongated bolt.  The
reasoning I read (it was ACI or AISC I can't remember for sure) was that the
strength of the bolt is not fully developed, and the failure can actually be
more sudden by "unbending" than yielding of the bolt.  In the case of a
building I think I'd feel safer with the most strength, especially when the
bolts are hidden in the wall and might not be noticed very readily.  But
this is, of course, up to the designer's judgement.

Ed