Calculation of Dry Materials for Slab concrete (Cement, Sand, Aggregate).

 

One of my social Media friend asked me that:

Question: I have concrete for my private home slab. Of course, it should be noted that the length of slab=15 m, the width of slab=10 m, the thickness of slab=15 cm. and in the map on the short side there are 4 each 10m long beams & on the long side there are 3 every 15m long beam, the hight of the beam is 30 cm & the width of the beam is 35 cm.

How much cement, gravel, sand needed? Concrete Mark is M200.

Solutions: thank you, dear bro most welcome!

Step 1: in this step we will find the volume of Slab & Beams:

Volume of Slab is => V1=15m x 10m x .15m = 22.5 Cum (Cum = Cubic Meter)
Volume of Beams => V2=0.3m x 0.35m x 85m = 7.65 Cum
Total wet concrete volume => V=V1+V2 = 22.5 Cum + 7.65 Cum = 30.15 Cum

Step 2: To prepare one cubic meter of wet concrete, a half or 53% of additional dry volume should be considered.  In estimation of raw material always multiply wet volume with 1.53 to get dry volume.

Now multiply the whole volume of concrete by 1.53, which is equal to:

Dry Volume => Vt=V*1.53 => 30.15 * 1.53 = 46.13 Cum

Step 3: Concrete Mark is M200 which is equal to 1:1.5:3 ratio It means that (1-part cement, 1.5-part sand, 3-Part aggregate),

Step 4: Let's add all the parts => 1+1.5+3=5.5

Step 5: Total dry material volume which is 46.13 cubic meters, is divided into 5.5 and multiply the corresponding part of each dry material is the same amount of dry material.

Cement=>46.13/5.5*1=8.39Cum Cement, Density of cement = 1440 kg/ m³
1 Big Cement=50 kg => 1Cum Cement = 1440/50=28.8 Big Cement, So 8.39*28.8=242 Big C

Sand=> 46.13/5.5*1.3=12.6 Cum, if 1 Dump truck=5.5 Cum, 12.6/5.5=2.2 Dump truck Sand needed.

Aggregate or broken stone=> 46.13/5.5*3=25.17 Cum, 1 Dump truck=5.5 Cum, 25.17/5.5=4.57 Dump truck aggregate needed.

Dear Bro: you can provide 242 Big cement, 12.6 Cum Sand, 25.17 Cum aggregate.