T-BEAM - support moment - best reinforcement arrangement?
T-BEAM - support moment - best reinforcement arrangement?
(OP)
Hi
there are different possibilities to position and arrange the reinforcement by a continues beam over a support. this is the case where you get the support moments into the beam with the tension forces in the slab.
I just wanted to find out the best solution for a case where the bars are actually quite heavy.
I prepared a sketch with four different solutions, would appreciate your comments or recommendations for it
BauTomTom
there are different possibilities to position and arrange the reinforcement by a continues beam over a support. this is the case where you get the support moments into the beam with the tension forces in the slab.
I just wanted to find out the best solution for a case where the bars are actually quite heavy.
I prepared a sketch with four different solutions, would appreciate your comments or recommendations for it
BauTomTom






RE: T-BEAM - support moment - best reinforcement arrangement?
ANY FOOL CAN DESIGN A STRUCTURE. IT TAKES AN ENGINEER TO DESIGN A CONNECTION."
RE: T-BEAM - support moment - best reinforcement arrangement?
RE: T-BEAM - support moment - best reinforcement arrangement?
So if you place some rebars outside the stirrup, you need to check if the concrete alone has enough capacity to transfer the force to such rebars. In short, is it acceptable the shear in vertical cut sections parallel to the lateral faces of the beam when the section leaves such thick bars outside the stirrups and studied cut section? If not, a shear-friction scheme is usually employed to determine the amount of transverse rebar required to meet such shear at such sections.
The determined capacity must be then anchored beyond the last bar where it is deemed necessary, and is usually considered additional to any other transverse rebar present that has its own whole capacity in use to meet another solicitation, such transversal bending.
RE: T-BEAM - support moment - best reinforcement arrangement?
But like ishvaaag has suggested - If too much of the reinforcement is placed in the flange and outside the web stirrups, then you would need to rely on shear flow only to ensure the force gets into the reinforcement steel.
A-A1 or A-A3 for me.
RE: T-BEAM - support moment - best reinforcement arrangement?
RE: T-BEAM - support moment - best reinforcement arrangement?
RE: T-BEAM - support moment - best reinforcement arrangement?
I agree A1 is also my favorite. For example 20mm diameter. Would you placed them like every 100mm gap between? My DIN code actually allows to use at the top the half width of the efficient width of the T beam. So for example when you see the T beam with a efficient 2m TOP member then you could distribute the bars in a 1m width.
---to ishvaaag ---
Of course the shear bars can be only considered inside the stirrup.
--- to keenaseng ---
Agree 100%
--- to slickdeals ---
You see the ACI says the whole effective flange width. The DIN says only the half
--- to all ---
So I see you definitely don't recommend two layers on top. Rather split the bars to the flinch. Of course the shear forces in the beam must be checked.
In which distance would you split the top bars?
BauTomTom
RE: T-BEAM - support moment - best reinforcement arrangement?
one other engineer is keep on telling me rather to put on top of the beam two layers of the 20mm bars, but I think it is really better to move them into the flunch.
It seams people are scarred to to untypical things which differ to the usuall and traditional way althought they are often more efficient
BauTomTom
RE: T-BEAM - support moment - best reinforcement arrangement?
RE: T-BEAM - support moment - best reinforcement arrangement?
BauTomTom