A variety of different chemicals and additives can be added to concrete to help keep it the a workable consistency while finishing, and to cure at the proper rate. These are particularly important when pouring concrete in very cold weather, when it can take too long for concrete to become workable enough to finish and cure, and very hot weather, when it can dry out and cure too quickly. There are also finishing techniques to help concrete cure properly in extreme weather conditions.
The many options in the kinds of concrete, colors and finishing techniques create many different looks. Exposed aggregate made of small pea gravel is available in different colors. The kind of tool used to finish plain concrete can determine how rough or smooth it is. Adding salt will leave tiny pits in the surface. Concrete can also be colored and stamped to look like other material such as brick, cobblestone, granite, etc. and many finishes and glazes are attractive indoors.
Concrete is ordered in cubic yards, but professionals can calculate how much that is by knowing the dimensions in linear feet and inches and how thick the concrete will be.
Patios and walkways require 3- to 4-inch depth while driveways need to be 4- to 6-inches deep.
Usually reinforcing is unnecessary for small patios or when permanent header or divider boards are used. Reinforcement is required if concrete is placed on unstable soil or must support a heavy structural load. There are chemical additives that can be added to reinforce concrete as well at traditional ‘rebar’ (reinforcement bar.)