Pouring a concrete floor slab successfully requires that you use the correct concrete mix for the slab. A concrete slab's strength depends on how the concrete its mixed. Mix the concrete well and you’ll pour a slab that’s likely to reach the concrete's rated compression strength. Mix the concrete poorly, though, and you could end up with a slab that fails to cure properly and may end up not achieving the hardness desired or could cure to a brittle state that's prone to crumbling. Fortunately, mixing concrete for a floor is not a difficult process. No previous experience is needed to get the mixture correct; it requires only the correct tools and procedure.
Pour the dry ingredients into a wheelbarrow or concrete mixer. Shovel in 1 part cement, 3 parts sand and 4 parts gravel to create a common concrete foundation.
Mix the dry ingredients thoroughly. Turn on the cement mixer to mix the materials inside. Use the shovel to mix the materials in a wheelbarrow. Mix them by folding the materials from the bottom of the wheelbarrow to the top of the material pile.
Add water to the dry mix. Use about 6 gallons of water for each 11.3kg. bag of cement you use. Add the water gradually to the mixture, using the rotation of the cement mixer to mix the water in with the dry materials, or folding the water into the dry material using the cement shovel for wheelbarrow mixing.
Mix the water into the dry materials until you have a concrete of uniform consistency, wet enough to pour. Use the mixed concrete immediately.
Wear safety goggles, work gloves and rubber boots during the mixing process, and cover as much of your skin as possible to prevent chemical burns from the material.