Masonry work, materials for 20 cum brickwork

Masonry work

Masonry is the construction of a structure by building up units such as bricks, stones or concrete blocks, bonded together with mortar. When the units are bricks it is called brick masonry; when they are stones it is called stone masonry. Good masonry has a strong bond, plumb and level courses, fully filled joints and proper curing.

Materials for 20 cum brickwork in 1:6 mortar

Given: brickwork volume $= 20\ \text{m}^3$; brick size 230 mm x 110 mm x 55 mm (actual size, without mortar); mortar joint $= 10$ mm; mortar 1:6 (cement : sand).

Step 1: Volume of one brick with mortar (240 mm x 120 mm x 65 mm)

$$0.24 \times 0.12 \times 0.065 = 0.001872\ \text{m}^3$$

Step 2: Number of bricks

$$N = \frac{20}{0.001872} = 10683.8 \approx 10684\ \text{bricks}$$

Step 3: Volume of bricks without mortar

$$10684 \times 0.23 \times 0.11 \times 0.055 = 14.867\ \text{m}^3$$

Step 4: Wet volume of mortar

$$20 - 14.867 = 5.133\ \text{m}^3$$

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

$$5.133 \times 1.27 = 6.519\ \text{m}^3$$

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

$$\text{Cement} = \frac{1}{7} \times 6.519 = 0.931\ \text{m}^3 = 1341\ \text{kg} \approx 26.8\ \text{bags (50 kg, 0.0347 m}^3\text{ each)}$$ $$\text{Sand} = \frac{6}{7} \times 6.519 = 5.588\ \text{m}^3$$

Answer: Bricks = 10684 nos.; cement = 0.931 m³ (about 26.8 bags); sand = 5.59 m³.