Adding to existing drive

   / Adding to existing drive #11  
Expansion joint, if I understand right your just adding to driveway and calling what you have already poured a slab
 
   / Adding to existing drive #12  
5 in slab is on the thin side for tying slabs together. If you have differential movement between the slabs, you have two inch of concrete resisting that force. It does not take much force to break two inch of concrete.
If you install dowels, you want to use epoxy so that the dowels are uniformly loaded
Cracks and joints in one slab will tend to continue into the next slab. Plan your joints in the new slab accordingly.
Rebar in the thin slab does not add much strength but it helps hold the crack together. If rebar is 24 inch on center, crack can grow to 24" before encountering a rebar. Fiber will intercept the forming crack in a much shorter distance.
If this was my slab , I would make the edge where the slabs abut to 8" thick for 12" in width.
 
   / Adding to existing drive #13  
The slab next to the house foundation and stem walls was poured about 3 years ago during initial construction. I'm simply tying into the existing slab to extend the driveway out so nothing new being poured next to the foundation.

In that case, then there's no need to pin the joint. Theoretically there shouldn't be any vertical movement. If you do want to pin the joint, then smooth rods and sleeves are typically utilized so the slab is restrained in the vertical plane, but it's still allowed to expand laterally. Of course, expansion would only be an issue if you are pouring a large slab (don't recall how big you were looking to go). Done lots of 5" slabs with 3/4" dowels @ 12" o/c.
 
   / Adding to existing drive
  • Thread Starter
#14  
In that case, then there's no need to pin the joint. Theoretically there shouldn't be any vertical movement. If you do want to pin the joint, then smooth rods and sleeves are typically utilized so the slab is restrained in the vertical plane, but it's still allowed to expand laterally. Of course, expansion would only be an issue if you are pouring a large slab (don't recall how big you were looking to go). Done lots of 5" slabs with 3/4" dowels @ 12" o/c.

This section will be 45' wide by 12' deep. Ill be doing another after this one.
 
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   / Adding to existing drive
  • Thread Starter
#15  
In that case, then there's no need to pin the joint. Theoretically there shouldn't be any vertical movement. If you do want to pin the joint, then smooth rods and sleeves are typically utilized so the slab is restrained in the vertical plane, but it's still allowed to expand laterally. Of course, expansion would only be an issue if you are pouring a large slab (don't recall how big you were looking to go). Done lots of 5" slabs with 3/4" dowels @ 12" o/c.

Hi Cord. I talked to a couple of guys I know in the business and they suggested doing something very similar to what you suggested, 5/8" holes 20" o/c with 1/2" bar, no epoxy so it can move. Finally got around to getting the pad formed up and ready to pour. Looks like Thursday or Friday may be a good day for it.

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