These are just a few examples. The strength and other properties of concrete are dependent on how these four ingredients are proportioned and mixed. The most common type of cement is Portland. Unlike steel, concrete is adequate in strength in only one direction. Concrete is very good in compression but useless in tension.
Engineering design is based on concrete's compressive strength .
To correct for the lack of tension strength in concrete, high tensile strength steel is placed in the tension side of concrete. The steel used for reinforcement usually consists of round steel bars often called rebars. When this combination occurs it is called reinforced concrete . When Civil Engineers design, they obviously need to know the strength of the material that they are using. The first test involves loading the concrete cylinder shown in the drawing until failure.