Civil Engineering - Estimating and Costing - Discussion

Generally to calculate the Cement, fine aggregate and coarse aggregate the following method will be followed,



Wet Qty. of concrete = 100 Sqm * 0.04m thickness = 4.00 m^3

To get the dry volume of concrete, generally wet volume of concrete will be multiplied by 150%.



Therefore 4.00 m^3 * 150% = 6.00 m^3.



Cement Qty. = Dry volume of concrete / ( Sum of the ratio values).



= 6.00 /( 1+2+4).

= 0.857 m^3 of Cement i.e.25 No. of bags.



But here they considered 164.5% instead of 150%.



Dry volume of concrete = 4 * 164.5% = 6.58 m^3.



Cement Qty. = 6.58/ (1+2+4) = 0.94 m^3 of Cement i.e. 27.5 bags.

The given answer is correct.

1st total volume=100 * 0.04 =4 m^3.
The volume is increased by 10% due to uneven surface which gives = 4 * 1.1 = 4.4 m^3.
This volume is further increased by 50% for dry volume calculation = 4.4 * 1.5 = 6.6 m^3.
So total volume = 6.6 m^3.
For cement = (6.6 * 1)/(1+2+4) = 0.9428 m^3.

Area =100 m^2.

Thickness = 4cm
= 0.04M
Volume = 100 * 0.04
= 4M^3
The Volume of cement = dry volume/sum of the ratio.
= 1.54/1+2+4
= 0.22 M^3
For 4 m^3 = 0.22*4.
= 0.88M^3.
So ,0.90m^3 is the right answer.

100 * .04=4cu.m of wet concrete.

To produced 1cu.m of concrete 1.54cu.m of dry concrete required.

1.54 * 4 = 6.16cu.m
6.16/1+2+4 = .88 cu.m of cement reqd.
.88 * 1440 (density of cement)=1267.2 kg.

Or,
1267.2/50kg = 25.34=26 bag of cement.

The correct answer is 94.
Volume of wet concrete in 4cum.
Volume of dry concrete is=4*1.54( constant),
Total v= 6.61.
Quantity of cement = 1/7 * 6.61 = 0.94.

The volume of wet concrete = 100*0.04 = 4.
Increased mortar by 65% in dry mortar.
The volume of dry mortar=4+0.65*4=6.6.

Now,
Cement QTY = 6.6/7 = 0.94ans.

Area = 100 M2.
Thickness = 4 cm = 0.04m.
Volume = 100*0.04 = 4 M3.
Add 54% of Dry vol = 4+ 54/100 * 4 = 6.16 m3.
Cement = 1/7 *6.16 = 0.88 m3.

The volume of concrete= 100 * .04 = 4.
10% increase for the unevenness + 50% increase for dry volume =4*1.1*1.5 = 6.6cum,
Cement=6.6/(1+2+4).

0.88cum.
Valume of dry cement concreat 100 * .04= 4cum,
Valume of wet concreat =4 * 1.54 = 6.16,
Valume of cement = 1/7 * 6.16 = 0.88cum.

1.54 is the conversion factor to convert wet to dry mix and additional they take 10% for unevenness & loss. So, total 1.64.