Details of grade of concrete, mix ratio and characteristic compressive strength for ordinary concrete

In this construction video tutorial, one can gather knowledge on groups of concrete, grades of concrete, mix ratios of concrete and characteristic compressive strength in N/mm2.

Compressive strength or compression strength refers to the capability of a material or structure to bear up loads in an effort to minimize size, as against tensile strength, which bears up loads in an effort to extend.

The compressive strength of concrete is provided by means of the characteristic compressive strength of 150 mm size cubes verified at 28 days (fck). The characteristic strength is described as the strength of the concrete under which not over 5% of the test results are projected to fall.

Usually, there are three groups of concrete like ordinary concrete, standard concrete and high strength concrete.

In ordinary concrete, the concrete grade, mix ratio and characteristic compressive strength are given as follow :-

For M5 grade Mix ratio - 1:5:10 and Characteristic Compressive Strength – 5 N/mm2

M7.5 grade Mix ratio - 1:4:8 and Characteristic Compressive Strength – 7.5 N/mm2
M10 grade Mix ratio - 1:3:6 and Characteristic Compressive Strength – 10 N/mm2

M15 grade Mix ratio - 1:2:4 and Characteristic Compressive Strength – 15 N/mm2
M20 grade Mix ratio - 1:1.5:3 and Characteristic Compressive Strength – 20 N/mm2

Here ratios are given as C(Cement) : S(Sand) : A(Aggregates). It is suggested not to use the grade of concrete that is under M20 in RCC work.

To gather more knowledge, watch the following video.

Video Source: Civil Engineers