First class brickwork in 1:6 mortar numerical

First class brickwork in 1:6 cement-sand mortar

First class brickwork is masonry built with first class bricks (well burnt, uniform in size, shape and colour, free from cracks, with a crushing strength of not less than about 10 N/mm² and water absorption of not more than 15-20%), laid in cement-sand mortar 1:6 in a proper bond (English or Flemish), with 10 mm joints, full mortar beds, staggered vertical joints, bricks soaked before laying, and the wall kept wet for curing for at least 7 days. It is used for the important walls of buildings.

Materials for 10 cum (10 m³) brickwork except bricks

Given: brickwork volume $= 10\ \text{m}^3$; brick size 57 mm x 115 mm x 240 mm (actual size, without mortar); mortar joint $= 10$ mm; mortar 1:6 (cement : sand).

Step 1: Size of brick with mortar

$$(0.25 \times 0.125 \times 0.067) = 0.002094\ \text{m}^3$$

Step 2: Number of bricks

$$N = \frac{10}{0.002094} = 4776.1 \approx 4777\ \text{bricks}$$

Step 3: Volume of bricks without mortar

$$4777 \times 0.24 \times 0.115 \times 0.057 = 7.515\ \text{m}^3$$

Step 4: Wet volume of mortar

$$10 - 7.515 = 2.485\ \text{m}^3$$

Step 5: Dry volume of mortar (add 27% for dry bulk, voids in sand, wastage and shrinkage)

$$2.485 \times 1.27 = 3.156\ \text{m}^3$$

Step 6: Cement and sand for 1:6 (sum of ratio $= 7$)

$$\text{Cement} = \frac{1}{7} \times 3.156 = 0.451\ \text{m}^3 = 649\ \text{kg} \approx 13\ \text{bags (50 kg, 0.0347 m}^3\text{ each)}$$ $$\text{Sand} = \frac{6}{7} \times 3.156 = 2.705\ \text{m}^3$$

Answer: Cement = 0.451 m³ (about 13 bags of 50 kg); sand = 2.7 m³.