Column Stirrups in Footing ??? 9

[Mohamed.Gamalsol]

Are column stirrups needed on combined or isolated footings according to the ACI Code or Euro Code , what is the reason for using them if we need them .

 

[Struct123ure]

Can you provide an image to clarify what you mean?
In general if the shear cannot be taken by the concrete, then yes stirrups are required.

 

[Mohamed.Gamalsol]

The clouded zone which I am asking about

 

[KootK]

1) I don't believe that North American codes require that ties be run into the footing. I've not done this myself to date.

2) For a gravity column, I struggle to see a need for the ties other than, perhaps, to hold the column dowels in place during assembly and concrete pouring.

3) To the extent that the column dowels need confinement or buckling restraint, I believe that one would normally assume the surrounding concrete mass to perform that function adequately.

4) For a moment frame, and particularly a high seismic moment frame, I can sort of envision a demand for such ties. In this situation, I'd expect a high shear "panel zone" of sorts to form in the footing where the column passes through. Still, to my knowledge this is not how we currently imagine the moment transfer to occur between the column and footing.

 

[1503-44]

It's just a convenient way to hold the dowel reinforcement together as it is being lifted and placed into position on the slab bottom reinforcement.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[JAE]

Usually you tie off the dowels with the top and bottom mat of footing reinforced, not extended column ties.

 

[dik]

I'd not do that... lateral support of the dowels is provided by the footing. In addition, I would not have keyed the footing into the slab. I'd have had 6" of granular fill between the top of the footing and the U/S of the slab... The dowel hooks would have been to the inside, too. It's unlikely that I would have hooked the bottom reinforcint, too.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[BulbTheBuilder]

ACI doesn't require ties in the foundation. From literature and what I have observed, this is typical per European standards. They are usually for construction purposes rather than strength.

Exactly for this reason as KootK mentioned

For a gravity column, I struggle to see a need for the ties other than, perhaps, to hold the column dowels in place during assembly and concrete pouring.

 

[hokie66]

I agree that the ties in the footing are provided solely for construction reasons. Some say this should be left to the builder, but I reckon anything I can do to assist is worthwhile.

 

[bones206]

There are exceptions for columns of wall boundary elements near the edge of a footing in SDC D, E, F. Per ACI 318-14 18.13.2.3, these elements would need transverse reinforcing around the longitudinal bars within depth of the footing.

 

[Mohamed.Gamalsol]

Thank you all, I agree that the tie are needed to protect edge failure

 

[jayrod12]

Your proportions don't seem to meet those requirements though. At least based on your section although there aren't actual dimensions of the footing in it. Maybe in plan view it's closer to the edge of the footing than half the footing depth.

Besides, the way that clause reads, they want blow-out reinforcing in the footing. Ties around your column verticals are not necessarily the same thing.