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Re: Steel Reinforcement Elongation Limit

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Now we're getting somewhere.....thanks

jim


----- Original Message -----
From: "Roger Turk" <73527.1356(--nospam--at)compuserve.com>
To: <seaint(--nospam--at)seaint.org>
Sent: Wednesday, July 26, 2000 5:39 AM
Subject: Re: Steel Reinforcement Elongation Limit


> Concrete is assumed to take no tension, therefore the cracking strain is
> zero.  Code permitted moduli of rupture vary between 6sqrtf'c to
12sqrtf'c,
> but this is valid only up to when concrete cracks.  Once cracking occurs
the
> moduli of rupture is zero.
>
> A. Roger Turk, P.E.(Structural)
> Tucson, Arizona
>
> Jim Korff wrote:
>
> <<Roger,
>
> Thanks for a good answer....
>
> However...it leads me to the question......what value do you utilize for
the
> cracking strain of concrete.... .003 ... .004...  .005.....or is that also
> irrelevant in our code dominated world..... ??
>
> jim
>
>
> From: "Roger Turk" <73527.1356(--nospam--at)compuserve.com>
> To: <seaint(--nospam--at)seaint.org>
> Sent: Tuesday, July 25, 2000 6:41 PM
> Subject: Steel Reinforcement Elongation Limit
>
>
> > ASTM requires 11 to 12 percent (min.) for Grade 40 steel, and 7 to 9
> percent
> > for Grade 60 steel.
> >
> > Since this is much beyond the cracking strain of concrete, the concrete
> will
> > crack and go along for the ride.  (Take a piece of paper and cut one
edge
> in
> > parallel strips and glue a rubber band across the strips.  Pull the
rubber
> > band and see if the glue comes loose.)
> >
> > At these strains, deflected shape becomes a part in determining the
> capacity
> > of the structure with the structure behaving like a cable supported
> structure
> > more than a flexural member.
> >
> > We (at least *I* do) want our structures to look like a sway-backed mule
> > before it collapses.  I do not want strains limited so that collapse
comes
> > suddenly and without warning.!
> >
> > A. Roger Turk, P.E.(Structural)
> > Tucson, Arizona
> >
> > Jim Korff wrote:
> >
> > >>The steel reinforcement "yield point" is at an elongation of .002
> (0.2%)
> >
> > Does ACI Code give a maximum permitted elongation for internal
> reinforcement
> > ??
> >
> > (For DIN it is 0.5% and for the Euro Standard it is 1.0% )
> >
> > Are there any papers or research on this subject -maximum elongation to
> > avoid steel/concrete bond failure ??<<>>
>
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