Cantilever Concrete Slab
Cantilever Concrete Slab
(OP)
Hi
I have a 5ft span cantilever concrete slab. How far I should extend the reinforcement past the point of maximum moment? Should that be only the development length? In order the clarify, I'm asking about the negative reinforcement that goes to the next span.
thank you very much
Nathan
I have a 5ft span cantilever concrete slab. How far I should extend the reinforcement past the point of maximum moment? Should that be only the development length? In order the clarify, I'm asking about the negative reinforcement that goes to the next span.
thank you very much
Nathan






RE: Cantilever Concrete Slab
RE: Cantilever Concrete Slab
RE: Cantilever Concrete Slab
RE: Cantilever Concrete Slab
A cantilever may create negative moments into the adjacent span that extend some distance from the support, sometimes even all the way across the span where you never develop any positive moment in the entire length at all.
Thus, what austim stated (and what DaveAtkins referred to in the ACI code) is the proper course here. The top bars must extend a distance beyond the point where they are no longer required. This distance in the ACI code is the greater of:
depth of member/slab
12 times the bar diameter
1/16th the span
RE: Cantilever Concrete Slab
I sincerely apologise for my half-baked reply. I wrote the post when my body temperature was a few degrees more than 98,4 Deg. F, but that is definitely not the excuse. You are right about short spans adjacent to the cantilevers subject to full negative moment. For an adjacent span of comparable dimensions my suggestion may hold good. The distance has to be calculated based on the moment distribution and the location of point of contraflexure.
Thanks.
RE: Cantilever Concrete Slab