Grade Of Concrete and Water Cement Ratio

In this Article with video today I will teach you that how to Find Grade of concrete with water cement ratio in detail so after reading this article and watching video you will be able to to now about Grade of concrete and water cement ratio in detail.
We have Given Grade of Concrete:
M5
M7.5
M15
M20
M25
So Here “M” Stands for Mix and Number is the characteristic compressive strengt of concrete after 28 days. and its based on the direct compressive test.
So, There for if I take M5 Grade Concrete so it means that concrete will gain the strength 5N/mm2 ater 28 days and M7.5 means that this is the strength of concrete 7.5N/mm2 after 28 days.
So , For all grade of concrete we used the same formulas.
Grade  Mix Ratio (Cement : Sand : Aggregate)  
M5  1 : 5 : 10  
M7.5  1: 4 : 8  
M10  1 : 3 : 6  
M15  1 : 2 : 4  
M20  1 : 1.5 : 3 
If you want to find the quantity of water for concrete mix so use the given formula:
Grade of cement  Water per bag (50 kg) cement  
M5  60 litre  
M7.5  45 litre  
M10  34 litre  
M15  32 litre  
M20  30 litre 
For more detail watch the following video of my channel
By : Engr Sami Ullah Stanikzai
Good
Send me ratio& classes of concrete
Please send calculate the water cement ratio and diffrent grade of concrete
I am learning from you thanks