pour concrete slab 4"thick on exxisting concrete slab

[tonysnowden]

have to pour slab on existing concrete slab and need to know how to bond the two together.do i need to use rebar,wire mesh or can use fibermesh concrete.
thank you for any advice on this matter.

 

[cvg]

cleaning, sand or shot blasting, dowels, bonding agents all can be used to help bond new to old. I'm not sure how wire mesh or fiber mesh would help bond. But, do you need to bond or can it function well if un-bonded?

 

[mitchelon]

First question should be, why do you need to bond the two slabs? What are you trying to accomplish with this bond?

 

[csd72]

You will never be able to get the two slabs to act as one.

Also the new slab will shrink and the old one wont, so if you bond the two together then be prepared for lots and lots of cracks (even with reinforcement).

 

[structuralaggie]

If possible, I would us a "bond breaker" if the design allows. Would work well in slab on grade situation, the new slab just needs to be thick enough.