The proportions of each ingredient in concrete should be retained properly. The process is known as concrete mix design. A good mix designer will begin with the properties which are required in the mix, then consider various factors, and arrange a detailed mix design.

A site engineer gives order for a diverse type of mix for a various purposes. As for instance, while casting a thin concrete wall in a hard-to-reach area, a mix that is more flowable than stiff should be ordered as the liquid concrete can outflow by gravity into each corner of the formwork.

It is recommended to apply a standard mix for most construction projects. The standard mixes range from M20, M30, M40 concrete, where the number indicates the strength of the concrete in n/mm2. So, M30 concrete contains a compressive strength of 30 n/mm2. A standard mix also indicates the maximum aggregate size. Aggregates belong to the stone chips used in concrete. For M30 / 20 concrete, M30 concrete with a maximum aggregate size of 20mm will be required.

Concrete that is cast in place in its mould is known as cast-in-situ concrete. Concrete members cast in a concrete factory and then supplied to site are known as precast concrete.



The followings are the common types of concrete :

High Strength Concrete:

The compressive strength is considered as the most fundamental and vital property of concrete. Concrete that contains a compressive strength of 40Mpa (5,800 psi) is known as high strength concrete.

High Performance Concrete:

High-performance concrete is identified depending on performance conditions like high durability, high strength, and high workability. High-performance concrete (HPC) is created with proper selection and proportioning of its ingredients like cement, sand, gravel, cementitious materials ranging from fly ash; silica fume; and slag, and chemical admixtures for example high range water reducing admixtures.