Dowel Bar Placement
Dowel Bar Placement
(OP)
A lot of times when we have L-shaped slab-to-grade beam dowel bars, the contractors prefer to "wet-stick" them during the grade beam pour, instead of the tying them to the grade beam rebar before the pour.
Is there any reduction in dowel capacity that should be taken if the dowel bars are placed in this manner? Does ACI comment on the matter? Any help would be greatly appreciated. Thanks.
Is there any reduction in dowel capacity that should be taken if the dowel bars are placed in this manner? Does ACI comment on the matter? Any help would be greatly appreciated. Thanks.






RE: Dowel Bar Placement
Wet sticking is not a good practice. Bond can be severely compromised.
RE: Dowel Bar Placement
thread507-244716: Wet sticking foundation dowels
RE: Dowel Bar Placement
RE: Dowel Bar Placement
Dont misunderstand me though, wall dowels in a footing should always be tied before placement. I am just trying to point out that there instances it is acceptable to wet stick.
RE: Dowel Bar Placement
The dowels from a top of foundation to a slab could be very critical bars necessary for the structure to perform as intended. By wet sticking you are ensuring that you won't know at all what sort of development you have in the bars.
I know wet sticking occurs, but it is never acceptable in my book.
RE: Dowel Bar Placement
RE: Dowel Bar Placement
For me the main disadvantage is that you're mixing up the trades, steelfixers fix rebar and masons place concrete. Of course we have all had cases where a few starter bars are out of position and we have to find a solution. But is there really any evidence that "wet sticking" avoids this problem.
RE: Dowel Bar Placement
RE: Dowel Bar Placement
BA
RE: Dowel Bar Placement
Does anyone know if the the masonry code address this issue? Wet sticking is also commonly done for masonry wall reinforcement splices during grout pours.
RE: Dowel Bar Placement
But I agree with Sir Ron that it's difficult to defend unacceptable practices when worst comes to worst.
RE: Dowel Bar Placement
I'm not defending the practice, but wondering how big a problem this really is? I know it is done all the time. With so many instances, shouldn't there be many examples of problems?
RE: Dowel Bar Placement
RE: Dowel Bar Placement
Theoretically, wet-sticking could be done so that proper bond is achieved between steel and concrete. The problem is that the inspector cannot tell after the fact what technique was used and hence how good the bond is.
BA
RE: Dowel Bar Placement
RE: Dowel Bar Placement
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Dowel Bar Placement
BA
RE: Dowel Bar Placement
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Dowel Bar Placement
In my typical example you are dealing with bars that have to bend down to slabs. I cant tell you how many times i see rebar detailers draw this bar being being bent before concrete placement. As if we are going to knotch our forms for every foot on center. Similiarly, when you are placing a 12" wall and half rebar sticking up 3' past the pour it makes it a nightmare for the pump operator or the guys and the operator on the bucket (cant lower bucket as rods are in the way). Now if you have someone right after the wall is being topped off wet stick staight bars into the pour, is someone here going to say there is a problem with that?
RE: Dowel Bar Placement
BA
RE: Dowel Bar Placement
1) ability to strike a flat surface with the screed, then insert dowels - just to make it easy.
2) the dowels do not have intersecting bars which can provide proper support to the free-floating dowels.
The solution is the addition of carrier bars to hold the dowels, and a bit more work at the screed. Otherwise, you have to use a have a piece of formwork to support the exposed portion of the dowels.
Tolerance on embedded length is -1 or -2 inches, depending upon bar diameter. If the bar is intended to develop tensile capacity, bond and development is critical, and this is only assured by proper embedded length and proper consolidation around the bars. Bars need to be placed and tied to prevent movement prior to concrete placement to assure depth of placement and that vibration can be carried out in fresh concrete with the bar inserted in its final position.
John Turner CSP PE
CRSI Greater Southwestern Regional Manager
RE: Dowel Bar Placement
If you have proper slump concrete (not soup) then stabbing a bar into properly placed concrete creates voids around the bars, limiting the pull-out strength. For a structural slab/beam system, these bars may be critical - taking stress and providing strength/stability in the assembly.
If so, then as an engineer, I cannot allow wet-stabbing as I KNOW that this creates uncertainty in my structure.
Contractually the contractor is required to bid and build the job per the drawings and specs - the drawings and specs will refer to "in accordance with ACI...". ACI requires pre-tied bars.
RE: Dowel Bar Placement
If the footing is 20" deep and the starter bars for the cmu wall extends 24" out of the footing, then the total fall of the concrete is 3'8" which shouldn't be a problem for placement of the concrete. Likewise if the starter bars are required at 16" crs then wouldn't it be easy to provide ties at 16" crs so the wall starter bars can be tied to the cage.