Quantity of materials required for 1:1:2 shotcreting 100sqm area 50 mm thick?

Question

Cement : 53grade portland

aggregate: 6mm down size

sand : between zone ii & zone iii

for indian cnditions

Answer 1

To calculate the materials as specified in your statement we may proceed as follows.

Total Quantity of concrete = 100 x 10.76 x 50 / 304.5

                                             = 176.51 Cft.

Remember,  1 sq. meter = 10.76 Sft

                        1 ft.             = 304.8 mm.

Now calculate the sum of ratios = 1+1+2 = 4

The Cement required          =   (176.51/4)x(1.54) x (1/1.25)

                                              =54.36 bags

1.54 is multiplied to convert dry volume to wet volume of concrete. The volume of a cement bag is 1.25 Cft mostly if it is not the standard at your place change the value  in denominator.

Sand                                   = (176.51/4)x 1.54

                                            = 68 Cft

Aggregate                        = (176.51/4)x1.54x2

                                          = 136 Cft.

Now if you need the quantities in meteric units ( as per your statement) these values have to be converted into metric units, which is as under.

Sand                               = 68/35.31 = 1.925 cubic meter.

Aggregate                      = 136/35.31 = 3.85 cubic meter.

Here

1 cubic meter                 = 35.31 cubic feet.

It is advised to add at least 3% for the wastage at the site. On the basis of my experience the wastage is about 3 to 5 % and it is highly dependent on construction techniques and attitude of labour.

I hope this will be helpful