maximum allowable size of cored slab

[cmrdata]

Does anyone have any rule of thumb on the maximum size can be allowed to core through an existing one way slab for misc piping penetration? 3"? 4"?
Can't find any criteria in ACI, and I assume this is more of an engineering judgement call. I therefore would like to hear what you think.
Thanks.

 

[TXStructural]

Any size that doesn't compromise the slab such that it cannot hold the required loads. That is, small cores near columns or supports could be too much (in shear), but any core which doesn't cut reinforcement at midspan might be just fine (in bending). If you know or plan to cut through reinforcement, it's fine, just be sure you have enough without whatever is cut. And never core PT slabs without knowing exactly where the tendons are located. It is entirely about engineering judgment, the original design, and the actual construction.

 

[cmrdata]

Thank you for your input, TXStructural. I also agree that it is an entirely engineering judgement matter, depending on the location, number and layout of the opening, to name a few.