Rebar pattern in a slab with circular openings
Rebar pattern in a slab with circular openings
(OP)
Hi Guys,
I am trying to design an 8 ft thick table top slab (52 ft x 15 ft rectangular) standing on concrete columns 8 ft x 8 ft. The columns stand on an 8 ft thick mat.
--- The table top slab has 4 circular openings of 26 ft dia each.
--- Very heavy circular drums will sit on anchor bolts around the openings. Its a very heavy seismic zone.
--- The concrete columns are at 4 corners, as well as on the perimeter between drums, totaling 10 columns.
--- The rebar pattern that I have decided for the slab is: longitudinal rebars between columns in N-S and E-W directions. For the circular openings, I have decided for rebars in circular pattern all around the openings, and in concentric layers in plan.
Guys, I want your opinions on the rebar layout, specially the circular pattern, as this is something which I have no precedent of.
Thanks in advance.
I am trying to design an 8 ft thick table top slab (52 ft x 15 ft rectangular) standing on concrete columns 8 ft x 8 ft. The columns stand on an 8 ft thick mat.
--- The table top slab has 4 circular openings of 26 ft dia each.
--- Very heavy circular drums will sit on anchor bolts around the openings. Its a very heavy seismic zone.
--- The concrete columns are at 4 corners, as well as on the perimeter between drums, totaling 10 columns.
--- The rebar pattern that I have decided for the slab is: longitudinal rebars between columns in N-S and E-W directions. For the circular openings, I have decided for rebars in circular pattern all around the openings, and in concentric layers in plan.
Guys, I want your opinions on the rebar layout, specially the circular pattern, as this is something which I have no precedent of.
Thanks in advance.






RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
sorry to catch your posts a little late.
the columns are 43 ft apart center to center. so the drum openings are OK. the 8 ft thickness is also OK. the slab dimensions are 170 ft x 50 ft. sorry for giving the dimensions in m instead of ft in my earlier post.
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
Otherwise I would look at 45 degree bars and hoop bars. The hoop bars could be inside the 45 degree bars so that you don't need an additional layer. You could then hook the longitudinal and transverse bars over the hoops to tie them into the cage.
Have you considered post-tensioning this thing?
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings
cooperDBM, post-tensioning is not an available option.
miecz, actually, due to flexure requirement, I need 4 layers (top and bottom) of rebars at any section. even with this, do you think that I can offset the rebars radially? if so, can you please explain in detail.
RE: Rebar pattern in a slab with circular openings
RE: Rebar pattern in a slab with circular openings