Treat it front and back with enzyme type treatment that you can get from a supply house.

The Zif wall paper remover enzyme works well and can be purchased at Home Depot.

It is an enzyme-action product that breaks down the urine into components that do not have an odor.

Then you spray the concrete slab with an enzyme that eats the urine out of the pores.

As said, I tried everything that I could think of (ozone generator, leaving windows/doors open for days, pouring bottle after bottle of cat urine enzyme cleaner, scrubbing the floor, and other solutions).

They often sell a product that will neutralize cat urine.Clean with a vinegar solution first, then treat with the enzyme cleaner.

Spray with a probiotic enzyme....let set for 3 days than ozone overnight with all cabinets open and air conditioner on to pull thru ductwork.

try using an enzyme cleaner (like for skunk sprays) to clean the subfloor thoroughly and then seal the subfloor with Zinner bin shellac.

I have another cleaning company who uses an enzyme product that they promise will absorb any odors.  

.), they quickly deteriorate the concrete components and cause failure.6) Adding various enzymes and bacteria is up for debate.