I know this is aside from the point, but I'm not sure there is any added value in installing a ground rod through an interior slab.
I guess I would be more concerned about having a good ground grid and bonding all systems coming in or out of the computer room.
And I hope the IT folks don't want to isolate the computer ground from the service ground...
To be honest I dont understand the reason either. The IT/comm manager for the client told me its per some TIA standards (TIA 607A?) but I haven't had time to look into it (4 deadlines this month, 1 big project coming, 4 under const., 1 about to get into conts.) but I will asap. The application as I mentioned is a data room which has dissipative tiles and copper bus bars on walls for easy grounding of the server rack, etc. bodies. The only reason i can think of off the top of my head is that another ground path at that point will decrease the impedance of the ground system at that point and will create less noise.
I have done isolated ground for other clients where they use an isolated testing chamber. In those applications we isolate grounding from the room, provide a chemically grounded well + rpd which provides isolated ground in the room and provide RF filters for each current carrying conductor entering the room. Chamber room mfg. have their own standards of sealing the room penetrations etc. and I got the details from them and tossed them on the drawings.
I would like to continue this discussion to find out why its necessary to provide another ground connection to struct. steel, cold water pipe, ground rod, etc. for this case. It'd be much appreciated if there was other input, else I'll post under this topic again once I review the TIA standards that the client's comm rep referred to.