71. The compressive strength of perforated bricks should not be less than
- 4 MN/m2
- 5 MN/m2
- 6 MN/m2
- 7 MN/m2
72. The bricks after moulding should be dried in
- Open-air
- Sun for 3 to 8 days
- Air for 3 to 8 days but not in the sun
- Hot air for 3 days
73. Which of the following constituent, when present in excess quantity in clay causes the bricks to melt and distort during burning.
- Alumina
- Silica
- Lime
- Alkalies
74. Presence of which of the following is responsible for imparting yellow tint to bricks?
- Alumina
- Silica
- Magnesia
- Lime
75. Brick containing large proportion of soluble salts liable to become patches of white deposit are called as
- Bloating
- Efflorescences
- Under burning
- Laminates
76. Why are bricks soaked in water before using in brick masonry?
- for removing dust
- for reducing air voids
- for preventing depletion of moisture from mortar
- for reducing efflorescence
77. Consider the following stages in the manufacturing of bricks
- Weathering
- Moulding
- Tempering
The correct sequence of these stages in the manufacturing of bricks
- i, ii, iii
- i, iii, ii
- iii, ii, i
- ii, iii, i
78. As per Indian standard code 1077, the burnt clay building bricks having compressive strength less than ________ N/mm2 are known as common burnt clay bricks.
- 40
- 30
- 12.5
- 3.5
79. Pallet board is used
- to make frog in the brick
- to mount the mould
- for table moulding of brick
- none of the above
80. The compressive strength of heavy duty bricks should be more than
- 40 N/mm2
- 20 N/mm2
- 5 N/mm2
- 3.5 N/mm2