Concrete Construction Joints 1

[stallion0002]

I remember reading somewhere that smooth bars are prefered over rebar as the dowels across a concrete slab construction joint. I checked IBC and ACI but can't seem to find the reference. Any help?

 

[bldgdesign]

ACI 360-06 or ACI 302.1-04

 

[stallion0002]

Thanks, but...

Chapter 35 of IBC does not recognize ACI 360 or ACI 302 as accepted standards. Is there anything else out there?

 

[sdz]

Depends what you're trying to do.
If you want to prevent movement, e.g. the longitudinal joint down the centre of a road, use deformed bars.
If you want to allow movement then use smooth bars, with bond breaker.

 

[hokie66]

And if you want to allow relative shrinkage parallel to the joint and avoid cracking caused by such, use square dowels with compressible material on the sides, or diamond plate dowels. This is a big subject in concrete slabs on ground, and requires a lot of study and experience.

 

[sdz]

Try this site

http://www.cca.org.nz/ach_des/joints.htm

 

[Ron]

It's mostly common sense....a dowel is to allow movement parallel to the dowel. If the dowel bonds to the concrete on both sides of the joint, such movement is prevented, thus negating the benefit of a dowel. You may use either deformed or smooth dowels; however, one side must be capable of sliding...it's just easier with smooth dowels as the only thing you need to do is grease them. With deformed dowels you will have to tape and grease them or use a pipe sleeve over them.

 

[Drumchaser]

slab....could be interpreted as many things.
Concrete pavement? - Continuous,Contraction, or Jointed.

Dowels are usually smooth and placed transverse in a rigid "basket", tie-bars are usually deformed and used to bond two pours together, and includes a sawcut and sealed joint.