top reinf for a cantilever beam and existing slab to be enlarged
top reinf for a cantilever beam and existing slab to be enlarged
(OP)
Hello,
I have 2 independent questions
1- For a cantilever beam where the top reinforcement can not be anchored in the column since the ldh (ACI318-08) is bigger than the columns dimensions, is it ok if i extend the top reinforcement into the adjacent slab and make a class A splice ? (refer to the attached section). (PS i dont want to decrease the bars diameter and increase their numbers)
2- An existing reinforced concrete solid slab needs to be enlarged. Dowels will be planted in the slab. A hole of 15 x bar diameter will be drilled and bar along a bonding agent will take place. The connection between the existing and the new slab is a pinned connection. Correct?
If i need to have a continuity and a moment connection, i should demolish a part of a slab and ensure that the bars have the adequate development length. Correct?
Thank you all
I have 2 independent questions
1- For a cantilever beam where the top reinforcement can not be anchored in the column since the ldh (ACI318-08) is bigger than the columns dimensions, is it ok if i extend the top reinforcement into the adjacent slab and make a class A splice ? (refer to the attached section). (PS i dont want to decrease the bars diameter and increase their numbers)
2- An existing reinforced concrete solid slab needs to be enlarged. Dowels will be planted in the slab. A hole of 15 x bar diameter will be drilled and bar along a bonding agent will take place. The connection between the existing and the new slab is a pinned connection. Correct?
If i need to have a continuity and a moment connection, i should demolish a part of a slab and ensure that the bars have the adequate development length. Correct?
Thank you all






RE: top reinf for a cantilever beam and existing slab to be enlarged
RE: top reinf for a cantilever beam and existing slab to be enlarged
What is the purpose of the bottom bars hooked each end?
How will you engage the column steel into the cantilever?
BA
RE: top reinf for a cantilever beam and existing slab to be enlarged
If you need continuity, you could do as you suggest or use a welded splice for each bar.
BA
RE: top reinf for a cantilever beam and existing slab to be enlarged
2) The connection will possess some degree of fixity but you're right, I would assume it to be pinned unless you've actually lapped the new and existing rebar for the required rebar tension. That said, you can often create a post installed rebar connection that laps new and existing bars without chipping away the existing concrete. See this doc for some ideas: Link
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: top reinf for a cantilever beam and existing slab to be enlarged
I have attached a sketch illustrating the above (sketch 1 is for question 2 and sketch 2 is for question 1 - not very logic - excuse me).
To Kootk,
This is how i am planning to make my column reinforcement.
Thank you for your answers
RE: top reinf for a cantilever beam and existing slab to be enlarged
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: top reinf for a cantilever beam and existing slab to be enlarged
RE: top reinf for a cantilever beam and existing slab to be enlarged
RE: top reinf for a cantilever beam and existing slab to be enlarged
For question 2, do the hooks at the ends actually overlap fully as shown? With dowels, I think you need to make sure that there is sufficient vertical reinforcement at the edge of the existing slab to catty the shear.
RE: top reinf for a cantilever beam and existing slab to be enlarged
Thank you all for your replies
RE: top reinf for a cantilever beam and existing slab to be enlarged
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: top reinf for a cantilever beam and existing slab to be enlarged
RE: top reinf for a cantilever beam and existing slab to be enlarged
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.