Initial setting time of cement for asbestos cement products should be not less than
30 minutes
50 minutes
75 minutes
90 minutes
Correct Answer :
D. 90 minutes
Related Questions
Which of the following timbers is suitable for making sports goods?
Mulberry
Mahogany
Sal
Deodar
The normal curing period for lime mortar, is:
1 day
3 days
7 days
10 days
Percentage of silica in a good brick earth lies between
5 to 10 %
20 to 30 %
50 to 60 %
70 to 80 %
For preparing porcelains, the clay should be
Sufficiently pure
Of high degree of tenacity
Of good plasticity
All the above
The process of decarbonising the pig iron completely and then adding proper percentage of carbon for manufacturing steel, is called
Cementation process
Crucible process
Bessemer process
Open hearth process
Which of the following trees yields hard wood?
Deodar
Chir
Shishum
Pine
A good building stone should not absorb water more than
5 %
10 %
15 %
20 %
Percentage of carbon content in mild steel is
Less than 0.25
Between 0.25 and 0.7
Between 0.7 and 1.5
Greater than 1.5
Durability of building stone is affected by its
Chemical composition
Texture
Resistance to atmosphere
All the above
The ultimate tensile strength of structural mild steel is about
160 N/mm²
260 N/mm²
420 N/mm²
520 N/mm²
Depending on the chemical composition and mechanical properties, iron may be classified as
Cast iron
Wrought iron
Steel
All the above
Red short iron cracks when bent due to the presence of
Sulphur
Carbon
Phosphorus
Silicon
The weight of 1 m3 of brick earth, is about
1200 kg
1500 kg
1800 kg
2000 kg
The proportions of charcoal, saltpetre and sulphur in gun powder by weight, are respectively:
15, 75, 10
75, 10, 15
10, 15, 75
10, 75, 15
Expanded metal is
Manufactured from steel sheets
Used for reinforced concrete in road pavements
Measured in term of SWM (short way mesh) and LWM (long way mesh)
All the above
The variety of pig iron used for the manufacture of steel by Bessemer process, is
Bessemer pig
Grey pig
White forge pig
Mottled pig
Dolomite is a lime stone which contains carbonate of magnesia upto
15 %
20 %
25 %
45 %
The slump recommended for mass concrete is about
25 mm to 50 mm
50 mm to 100 mm
100 mm to 125 mm
125 mm to 150 mm
Elastomers can extend upto
Five times their original dimensions
Seven times their original dimensions
Ten times their original dimensions
Three times their original dimensions
Pick up the correct statement from the following:
The heating of a material to redness in contact with air, is known as calcination
The property of lime by which it sets or hardens in damp places having no free circulation of air is called setting
The product that remains after calcination of limestone, is called lime
All the above
Which of the following sedimentary rocks changes into quartzite by metamorphic action?
Sand stone
Lime stone
Shale
Gypsum
Stones used for the construction of retaining walls must be
Soft
Hard
Light
Heavy
Quartzite is a
Metamorphic rock
Argillaceous rock
Calcareous rock
Siliceous rock
Gypsum consists of
H₂S and CO₂
CaSO4 and H₂O
Lime and H₂O
CO₂ and calcium
Iron ore may contain
Carbon
Silicon
Phosphorus and manganese
All the above
The most important constituent of varnish, is
Drier
Solvent
Resin
All the above
The main constituent of fly-ash, is
Aluminium oxide
Silica
Ferrous oxide
All of these
Ultimate strength to cement is provided by
Tri-calcium silicate
Di-calcium silicate
Tri-calcium aluminate
Tetra calcium alumino ferrite
The clay to be used for manufacturing bricks for a large project, is dugout and allowed to weather throughout
The monsoon
The winter
The summer
None of these
The pressure acting on the stones in stone masonry construction should be
Along the direction of bedding planes
At 45° to the direction of bedding planes
At 60° to the direction of bedding planes
Perpendicular to the direction of bedding planes