Concrete Calculator
Even though there are many different types of concretes, the word of "concrete" is normally referred to the Portland cement, which probably is the most widely used construction material in the world. In actual usage, concrete is normally mixed with reinforcing materials, such as sand, fibers, etc. Pre-mixed concrete can normally be purchased from stores in 60 lb bags or 80 lb bags. If a large amount of concrete is needed, it can also be delivered in concrete mixer truck.
Mixing is a very important step. Thorough mixing is essential for the production of strong and uniform concrete. Once mixed, concrete is a paste that can be poured to where it is needed. After this, it will gradually harden. This process is called curing. To achieve best strength and hardness, concrete should be cured in a humid environment with appropriate temperature. This is especially important in the first three days. In practice, this is achieved by spraying water or placing plastic covers. It can take a few weeks for the concrete to reach more than 90% of its final strength.
* This concrete calculator uses the pre-mixed cement density of 2,130kg/cubic meter or 133 lbs/cubic foot (60 lbs/0.45 cubic feet or 80 lbs/0.60 cubic feet) to obtain the weight needed. Different concrete can have very different density.