inserting masonry dowels

[RCCpm]

What is the best method recommended for installing masonry rebar dowels into a concrete foundation wall when there is no steel in the wall to tie to? Is "wet sticking" acceptable? What are the advantages/disadvantages to "wet sticking"?

 

[engineertipsman]

So your wall is unreinforced, but there are bars shown going into the footing? how tall are these bars?

 

[ron9876]

I see a lot of wet sticking with the dowels all over the place.

 

[BAretired]

The best method is to tie the dowels to the footing steel.

BA

 

[a2mfk]

I have always been taught to not allow insertion of anchors, rebar, etc. into the concrete during the placement operation. This can form small voids around the rebar and effect bond strength with the cured concrete, and is also pretty inaccurate way of placing steel. I'd have to dig a little but I think ACI has specifics on this subject.

Not to contradict myself, but it sounds like a means and methods question and I let the contractor make the decisions in the field as long as the as-built structure is per the drawings and specs (and no wet-setting!). But typically they use the foundation form boards, horizontal temp rebar braces and wire ties, and/or tie it into the foundation footing rebar.

 

[RCCpm]

I may have caused confusion when I indicated that there was no rebar in the wall to tie to. The vertical bars in the wall is too far to the inside face of the wall, such that the straight masonry dowel bars are not close enough to tie to. The dowels are coming up into the "brick ledge" and would require a lot more work and possibly more material to tie the dowels in place prior to concrete placement.

We had some bars installed by wet setting and the inspector did not like it, but accepted most bars.

Has anyone heard of hitting the bars on the end with a hammer and listening for a certain kind of "ping" sound to determine if they are set properly? The inpsector performed this "sound test" and determined that 3 bars sounded "bad" and is requiring drilling new dowels next to these three bars. Any thoughts on this type of test method?

 

[BAretired]

Forget the "ping". It is not reliable.

BA

 

[msquared48]

You stated that "The dowels are coming up into the "brick ledge" and would require a lot more work and possibly more material to tie the dowels in place prior to concrete placement."

That is not an excuse to avoid doing the installation the correct way. Just put in the extra labor and add a few bars if you need to. Quit fighting the problem.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[concretemasonry]

The original post said there was no steel (structurally) in the wall, so the dowels are not transferring loads due to flexure, but probably only shear and consequently bond strength is of no importance.

The project sounds a like a residential job and may only have a wall height of possibly 2' to 4' high, but not over 8' high. Often a strip footing can legally be built with no longitudinal steel (depending on the thickness and width) since shrinkage is not a factor. Very often, a contractor may stab in vertical rebar to get shear even though the drawing do not require it since it allows lateral restraint of the bottom of the wall am makes back fill bracing eassier and more effective. - Especially true if it is an 8' high wall and the interior floor slab is always poured later after the structure is up and plumbing and mechanicals are in place.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.