Rebar at Wall Footing 1

[NewbieStruct]

We have a condition on the site where in lieu of two masonry dowels into the footing, the contractor has only one going into the footing. The wall has only rebar at each face. The rebar at each face is required for the out of plane loads. Is this acceptable ?

 

[OHIOMatt]

No

 

[hawkaz]

Depends. Need to know more about the wall. Is this a cantilevered fence wall? If so, then both bars are required to be doweled to the footing. If it is a pinned base of a braced wall, one might be sufficient.

 

[NewbieStruct]

So what would be the fix?

Epoxy dowels into the footing?

 

[NewbieStruct]

The wall is assumed to be pinned at the bottom. Aren't the dowels into the footing just for shear?

 

[DaveAtkins]

If the base is pinned, one dowel should be fine.

DaveAtkins

 

[OHIOMatt]

Your question, answers itself. You state that "The rebar at each face is required for the out of plane loads." So, if the bars are required, as you state, and they did not put them in, then how would it be acceptable?

Are you or your firm the Engineer of Record for the project? Only that person can answer this question.

 

[NewbieStruct]

Yes, the base is pinned and the wall is braced at top by a concrete slab.

 

[BAretired]

How thick is the wall? Is the bar installed in the middle of the wall or on one side? Is there a shear key on top of the footing? What is the shear between wall and footing? A section might help.

BA

 

[NewbieStruct]

The wall is 8" thick. The footing dowel is in the center of the wall. There is no shear key at the top of the footing. The shear at wall and footing is approximately 200 plf.

The contractor assumed the dowels to be single since the main rebar at the wall is centered. The wall has each face reinforcing at a 4'-0" jambs across the building. The wall has been built 4'-0" tall already but has not been grouted.

 

[BAretired]

Okay, if the bar size and spacing is adequate to resist the shear, I would say it should be acceptable. It seems a little unusual to me to use bars each face on 8" masonry walls. I would have expected them to be one layer in the middle. Does anyone else try for two layers in an eight inch CMU wall?

BA

 

[hokie66]

First you said there were supposed to be bars on each face, now you say the main bars are centred...except for each face at 4' across the building. If you can't describe or depict the problem accurately, it is no wonder that answers will vary. At any rate, why are you asking us? If you work for the design engineer, ask him/her.

BA, yes, sometimes. Basement walls are frequently reinforced first outside, then inside, then outside again. Sometimes, the bars are detailed the same on both faces to avoid mistakes.

 

[BAretired]

Masonry basement walls may be permitted in our code but I have never specified them for retaining earth. The clear dimension between face shells in an eight inch masonry wall is only about 5" so I specify one layer of reinforcement at mid-depth. For basement walls in my locale, cast-in-place concrete is normally used. They are reinforced on both faces.

BA

 

[hokie66]

Then it obviously varies with locale. Reinforced block walls are commonly used here for both cantilevered and basement walls. Concrete is arguably better, but block is usually more economical.