Cutting Every Other Bar at CC Joints 1

[STR04]

Does anyone here construct his or her slab on grade details to show every other bar being cut at crack control joints before the slab is placed? Say if you schedule #3@12" EW and at the CCJ you cut the bars before concrete is placed thus decreasing your area of steel across the joint to #3@24".


TIA

 

[archeng59]

I specify that every third bar be continuous thru a sawed joint, but not thru a keyed construction joint. I tried every other bar, but cracks sometimes formed adjacent the sawed joint. never knew for sure if it was because the contractor sawed the joint too late or just too many bars thru the joint. but, since doing every third bar, have not had the same problem.

 

[apetr26542]

I would think that amount of steel across your control joint may still defeat the purpose, usually with WWF the alternate cross wires are cut. If I have rebar reinforcing, I end up with a smoothed doweled joint, greased one end.

 

[archeng59]

I've used the smooth dowels (basket dowels), also. As a VE item on one project, the owner and architect agreed to eliminate basket dowels for every other deformed bar continuous thru the joint with my concern about cracks forming elsewhere besides along the joints. the bars were spaced at 16" o.c. each way, so the continuous bars were at 32" o.c. thru the joint. that job went well, so tried it on a few more with the occasional extra crack results described above. now I'm using "every third bar" being approx. 48" o.c. and so far so good.

 

[STR04]

archeng59,

Can you tell me where ACI or PCA recommmends this practice?

Thanks,

STR04

 

[apetr26542]

I like the every third bar, ever use it on a more heavily reinforced slab?