sawcutting of concrete topping on concrete plank

huangyhg

sawcutting of concrete topping on concrete plank
we have a 2" concrete topping on concrete plank.  what is standard practice?  
is advisable to sawcut the topping?  
if so would you cut 1/4 of the depth?  
what kind of spacing would be used?
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i've never heard of using control joints in topping.
i concur with structuraleit.
i have never seen this done. the top surface of a precast piece (plank, double t, hollow core, etc) that is to recieve cip concrete topping is intentionally roughened. the bond between the roughened surface and the topping concrete is quite substaintial. i think even if you cut a control joint in the topping, it would be so solidly bonded to the precast, that the joint would not make much difference as the topping can't move relative to the pc anyway.  
there is absolutely no reason to cut control joints in concrete topping on single span plank.  
however, at the centerline of supports where plank is butt-jointed, it is advisable to cut a control joint in the topping.
for hollow core plank, you can cut along every other plank joint, basically 8 feet on center.  no cuts in the opposite direction.  if the topping is composite i would call the plank company or engineer first.