Dry Concrete Mixer

My husband was a stonemason for over 40 years and i have seen him dig out a shallow depression where he wanted the slab then fill it with dry concrete or mortar then lay the flat stone on top, fill the cracks with dry concrete and sprinkle it with water and it would set up and some of the first ones are still fine after all this time so it does work.Woudnt work for a slab that you were going.