Pouring concrete is a process that requires attention during every step. The final step in pouring concrete is curing. The curing process is where the concrete builds up its strength. Concrete is already wet when you begin pouring it, but it must be kept damp during the curing process.
Concrete Mixture
Concrete is a mixture of aggregate, binder material, additives and water. Aggregate consists of gravel, sand or crushed stone. The binder is the cement added to the mixture to allow it to harden. An additive is part of the mixture when you want the concrete mixture to set up a certain way, primarily used in winter to prevent the concrete from freezing before it cures. The concrete mixture contains 6 percent air, 11 percent cement, 41 percent crushed stone or gravel, 26 percent sand and 16 percent of water. The concrete is very wet at this point.
Foundation
You need a good, level foundation before you begin pouring the concrete. The foundation must be tapped down to make it solid, and plastic must be placed over the dirt so the ground will not draw the water out of the concrete. A good layer of sand, about 2 inches, must be placed over the plastic. If you pour a large patio or driveway, you need reinforced bars placed on top of the sand to prevent the concrete from cracking. Using three people to pour the concrete allows you to each work the concrete efficiently. While two people spread the concrete mixture, the third person can screed, which is a 10-foot straightedge used to push the concrete around like a bulldozer. The concrete is very wet at this point.
