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Re: z factor for crack control

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In a message dated 97-08-12 12:35:47 EDT, you write:

<< it is still an open debate about what is an acceptable crack width before
needing repair. >>

For one thing, if you get 0.0207, then the rebar is yielding and you know
there is a structural problem.   Before anyone panics, keep in mind that the
crack surface is often larger than the actual crack inside where the
reinforcement is, so don't jump to conclusions.  It takes a bit of judgement,
and therefore I suggest some latitude in assessing what should be an
acceptable crick width.  Also, lets keep in mind that the crack width is just
one piece of the equation: factor in the actual exposure and other
site-specific conditions.  Also, how is the structure going to be maintained?
There's also the liability for designers defending the cracks in their
project - and there will always be cracks - against those who might find it
convienent to mis-represent what significance the cracks really have.  That's
scary.

However even more scary is, as Bill indicates, when service performance is
ignored.  That goes for not only the designer but also for those who
supposedly take care of the structure once it's built. Maybe there's some
people out there who could relate some interesting experience in repairing
damaged concrete buildings.