Min. reinforcement for footing
Min. reinforcement for footing
(OP)
I notice 0.0018bh min tensile reinforcement discussed in this board.
I have a sign footing, only need min. reinforcement.
for my 20" thick footing, that requires #6@12" spacing each way.
for my 42" thick footing, that would mean #6@ less than 6" spacing each way. would this be too much?
For my sign footing (say 5'x10'), do I need to make it below frost line? If so, I need to make it 42" deep.
I have a sign footing, only need min. reinforcement.
for my 20" thick footing, that requires #6@12" spacing each way.
for my 42" thick footing, that would mean #6@ less than 6" spacing each way. would this be too much?
For my sign footing (say 5'x10'), do I need to make it below frost line? If so, I need to make it 42" deep.






RE: Min. reinforcement for footing
RE: Min. reinforcement for footing
Just wondering whether we need to go down below frostline. I read the code, it did mension small area/uncritical project may allow.
RE: Min. reinforcement for footing
42" is not that far down. Just do it.
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Min. reinforcement for footing
Don't be silly. A footing with those dimensions must be reinforced.
johndeng,
Mike is correct. As sign footings go, this one is small. Just do it.
RE: Min. reinforcement for footing
I did some pier foundations with plain concrete. I never designed plain concrete footing with larger size. from what you are saying, is it needed for construction purpose or t&s? any limit for plain concrete footing?
Just feel too much steel bars. Say footing b=5', h =42", 0.0018bh= 4.536 sq inch. so we need (10)#6 for 5' footing.
if h=24", I only need (6)#6 for 5' footing.
RE: Min. reinforcement for footing
As this is a sign footing, you will need reinforcement both top and bottom, so using the actual structural depth does save a bit.
In this footing, you do not need "T & S" reinforcement. Perhaps the minimum requirement for flexural reinforcement concides with the amount required for T & S, but it is for flexural purposes. Thus, you actually need 0.0018 bd x 2.
RE: Min. reinforcement for footing