Volume of wet cement concret is 1.54 to 1.57
Detailed analysis on M20 = 1:1.5:3 (Ratio)
As we know that during concreting when we place wet concrete , it gets harden after certain standard time( 30 mins IST & 10hrs FST), considering same it had be decided upon by Civil design Engineers to take a factor of safety ranging from 1.54 to 1.57 to counter that shrinkage.
i.e volume of dry Concrete = 1.54 to 1.57 times Volume of wet concrete.
Now calculations is as follows for 1cum(assumed) of Concrete work
ratio Sum = 1+1.5+3=5.5 Shrinkage or safety Factor =1.57 (you can take 1.54 also)
So Total volume of wet concrete required is :- 1.57cum
Volume of broken stone Require = (3/5.5) x 1.57 = 0.856 m3 Volume of sand Require = (1.5/5.5) x 1.57 = 0.471 m3 Volume of cement = (1/5.5) x 1.57 = 0.285 m3 = 0.285 x1440 = 411 kg For 1m3 of M20 (1:1.5:3) Broken stone = 0.856 m3 Sand = 0.472 m3 Cement = 8.22 bag.
Some important conclusion from above
8 bag of Cement is required for 1cum of concrete work in M20.
4.4 bag of cement is required for 1cum of concrete work in M10.
volume of dry concrete =1.54 times volume of wet concrete.
Thank You Folks!
Dr Uttam Kalwane
D.Y.Patil College of Engineering and Technology
Shri Mata Vaishno Devi University
Bharati Vidyapeeth Deemed University
Manipal Institute of Technology, Manipal University
Nagendra Naik Bukke
Sree Vidyanikethan Engineering College
Koneru Lakshmaiah University
Nakhon Ratchasima Rajabhat University
Abhishek Kumar Singh
Larsen and Toubro