Shouldn't you chip off the top surface of the old concrete until you see
the aggregate? We were always taught that the top layer of concrete was
the weakest and should be removed if you want a good bond with the new
concrete.
Jon Rush
George P Dausch IV wrote:
> 2. Sweep off the original, then water blast to remove all loose stuff.
> Allow to thoroughly dry and form the edges. Apply a coat of concrete
> bonding agent according to directions. Pour somewhere arond 1.5"/2" of a
> very high strength pea gravel mixture with fiber. This gives a bonded
> slab, but counts on the integrity of the existing slab. Cracks in the
> original will migrate upward eventually, even if forced into preplanned
> control joints.
> In either of the above cases, concrete thickness is the minimum from the
> highest elevation of the existing.
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