[Nealtw]

I have used anchor bolts. You can use a coupler nut to add a bolt to make them longer.

The come in many lengths be you only have to set them in 3"

The do make those treaded bolts 12" long. But some expensive.
1/2" x 12" Simpson Strong-Tie Titen HD Screw Anchor Zinc Plated, 5/Box (concretefasteners.com)

 

[Nealtw]

Would the rebar need to be bent into the shape of a staple? Or could it be cut it into small "prongs" that stick out from the slab?


View attachment 743993

You could epoxy them in long and when set just bend them and tie them.
Drill half inch for 3/8" rebar.

 

[Nealtw]

I'm working in a fairly narrow dug-out channel next to the slab so the bending would have to occur beforehand. But could I install the prongs and then wire-tie lengths of rebar to the prongs, basically substituting short ( ~ 8 inch) epoxied pieces of rebar for the concrete anchor screws?

Yes, I have not used epoxy for that but it is the approved method just tieing it should be fine.

 

[Nealtw]

Why would you not trust the manufacture's advice? Have you measured the thread outside diameter? We have no idea what you have or what size the threads are.

The threads are bigger on those so you do drill 1/2" for a 1/2" bolt, I don't think he has them in hand.

 

[Nealtw]

Check out page #2 for hole size.
Powers 7216 3/8 x 4 Wedge-Bolt OT Concrete Screw Anchor Zinc Plated - Mutual Screw & Supply

Different brands with different info , interesting, good catch.

Simpson Strong-Tie - THD501200H 1/2" x 12" Simpson Strong-Tie Titen HD Screw Anchor Zinc Plated

These anchors come packaged with 5 pieces per box and are designed for fastening items to concrete.

• Bit size 1/2"