Compression is used with concrete. A simple test standardized by ASTM C39 is regularly used by the professionals in order to control the compressible strength (fc’) of concrete. The strength assigns the units pounds per square inch, shorty called psi. Additionally, the strength determines the high compressible stresses to which the specimen are usually subjected. For that purpose, you should know how to apply the formulas and the specifications. With the help of the diagrams and the fc’ you can have the correct result about the compressions and the tension. As a result, you will be able to avoid cracks.