Time to Drill Cores through Concrete Slabs
Time to Drill Cores through Concrete Slabs
(OP)
Can anyone give a rough estimate of the time to drill 3" or 4" DIA. vertical holes through 4.5" of LW Concrete? I'm looking to reinforce an existing composite slab by drilling cores, welding on new studs and then filling with non shrink grout, and I'm looking for a rough estimate of the time involved to drill the cores.
One Architect I know thought it would take an hour per core, which seems absurdly high, I'm thinking more like 10 minutes each core, but that is just a gut feeling. I'm curious to know if someone with experience doing this could give a more accurate answer.
Thanks!
One Architect I know thought it would take an hour per core, which seems absurdly high, I'm thinking more like 10 minutes each core, but that is just a gut feeling. I'm curious to know if someone with experience doing this could give a more accurate answer.
Thanks!
Licensed Structural Engineer and Licensed Professional Engineer (Illinois)






RE: Time to Drill Cores through Concrete Slabs
RE: Time to Drill Cores through Concrete Slabs
RE: Time to Drill Cores through Concrete Slabs
RE: Time to Drill Cores through Concrete Slabs
And if the occupancy below is an attorney, the cost to do the coring will be higher than other occupancies - based upon my direct experience of having "trashed" an attorney's office space on one occasion
RE: Time to Drill Cores through Concrete Slabs
Drill the holes and epoxy rebar into the hole to use as an anchoring stud.
If you are concerned about fire resistance, you can use a high temp structural epoxy; however, the epoxy will be insulated by the new concrete as well.
You could also consider Dywidag expansion or resin anchors as well as other expansion anchors.
RE: Time to Drill Cores through Concrete Slabs
RE: Time to Drill Cores through Concrete Slabs
Licensed Structural Engineer and Licensed Professional Engineer (Illinois)
RE: Time to Drill Cores through Concrete Slabs
IsaacStructural: you have existing steel beams, supporting an existing concrete slab (on metal deck?) that you are trying to make composite via new shear studs, or equal, to the top flange, right?
RE: Time to Drill Cores through Concrete Slabs
Licensed Structural Engineer and Licensed Professional Engineer (Illinois)
RE: Time to Drill Cores through Concrete Slabs
You might consider using stud rails in a fashion similar to the approach steellion noted.
Sorry for the confusion.
RE: Time to Drill Cores through Concrete Slabs