cranked steel bars in ACI 318
cranked steel bars in ACI 318
(OP)
hello,
I don't have an experience in cranked steel bars in ACI 318,
could you please refer to the conditions in ACI 318 that define he procedure and limitation ?
Also Why the ACI stop recommend this method?is it because of the earthquake behavior?
I don't have an experience in cranked steel bars in ACI 318,
could you please refer to the conditions in ACI 318 that define he procedure and limitation ?
Also Why the ACI stop recommend this method?is it because of the earthquake behavior?






RE: cranked steel bars in ACI 318
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: cranked steel bars in ACI 318
Thanks
RE: cranked steel bars in ACI 318
RE: cranked steel bars in ACI 318
Back to our main point ,could you refer to ACI procedure for this(Clauses).
Thanks
RE: cranked steel bars in ACI 318
See 318-11 11.4.6.5 for the shear contribution.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: cranked steel bars in ACI 318
But the last Closure is 11.4.6.4, besides I am also looking for moment requirement besides shear(where to bend ,how much to bend,etc,)with reference to code requirement .
RE: cranked steel bars in ACI 318
RE: cranked steel bars in ACI 318
If you have one of the older CRSI manuals, you can probably find flexural detailing procedures there.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: cranked steel bars in ACI 318
But with alternating live loads on a continuous set of spans the negative moment inflection point extends some distance past the positive moment inflection point.
So it makes it difficult to use the same bar for both positive and negative moments as the bar is needed in two separate locations at the same point along the beam.
In checking older beams for new loads we always have a lack of steel near the upturn in the bar, either positive or negative.
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RE: cranked steel bars in ACI 318
1) is there a standard slope to the sloping portion?
2) would one use normal straight bar extensions past inflection points? Or assume the trussed bars fully developed at the bends? Or as a standard hook development condition at the bends?
3) not all of the reinforcing is hooked typically, correct?
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: cranked steel bars in ACI 318
1) No - I've seen many different variations of slope
2) Generally you have two conditions:
I think the trussed bars are developed at the bends - but even with that they occur many times way too soon.
3) The historical practice appears to be that truss bars (bent bars) were used in conjunction with straight bottom bars and much more seldom were straight top bars added.
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RE: cranked steel bars in ACI 318
Quoting from Winter et.al., based on the 1963 Code, "the ACI Code requires only that the inclined part of any such bar make an angle of at least 30 degrees with the longitudinal part". He further stated that they are usually bent at 45 degrees. This was of course a provision for diagonal tension.
I think JAE has described the practice correctly.