Bricks, Masonry, Asphalt and Concrete - Filling Hole In Slab Foundation

I own a Ranch on a concrete slab (no crawl space), which recently had a hot air furnace removed, which left behind a 2'X2' square hole in the slab. I need to fill the hole with concrete. Also, the repair needs to be able to hold the weight of a water heater. I am uncertain how to make sure that the repair will adhere well to the current foundation and not sag or separate. I was going to do the following, undercut the hole, apply concrete adhesive to the sides of the hole, insert a wire mesh anchored to the sides of the hole, then fill with concrete.

Any thoughts or suggestions?

Thanx,

Frank

The way I have handled this in the past is to dowel in small rebar (#3 or #4) with an epoxy adhesive, lay mesh on top of the bar and wire it secure and then pour concrete. This should make it stronger than the original concrete and give you plenty of strength for whatever you want to put on top.