How to choose the perfect grades of concrete for building construction

In a construction work there are various types of concrete grades which are dependent on the needs of structural design. The grades of concrete vary according to various types of construction projects but the proper selection is very crucial.

There are two types of concrete mix like Nominal Mix and Design Mix.

Nominal Mix - It is utilized for comparatively insignificant and easier concrete works specifically small scale construction like residential buildings. Under this type of mix, all the materials are conventional and their proportions are stipulated. So, no divergence occurs by the designer. Nominal mix concrete is applicable for concrete of M-20 or lower i.e. M5 , M7.5 , M10 M15 , M20 etc. M15 to M20 grades are applied for RCC works. This type of concrete mix contains superior strength. Nominal Mix concrete is mostly suitable for small construction project where high strength is not necessary.

The M15 Grade of concrete is suitable for the Plain Cement Concrete (PCC) construction works to attain normal strength for the structure. M20 Grade of concrete is applied for the Reinforcement Cement Concrete (RCC) construction works.

Second Step:

DESIGN MIX: It refers to a performance based mix where selection of elements and proportioning are settled by the designer independently. The user should indicate only the requirements of concrete in fresh and hardened condition. The requirements in fresh concrete belong to workability and finishing characteristics, while in hardened concrete these primarily refer to the compressive strength and durability.

Third Step:

In Design Mix Concrete, mix proportions are acquired from different lab tests. This type of Concrete types is utilized for the enormous projects, where high strength is very essential for the project. But the Design mix concrete is very much costly, so it can be only used for the high level projects.

In design mix concrete, higher grades of concrete like M30, M35 , M30 , M45 etc. are employed. Design mix concrete is applied to build up the dams and airport etc. where the high strength of concrete is essential to develop the superior quality project.

Video Source: Sami Ullah