MCQ
28621. The silica in Portland cement should be
10 to 20%
20 to 25%
25 to 40%
40 to 60%
28622. The normal consistency of Portland cement is about-
10%
15%
20%
25%
28623. The fuel generally used for burning limestone is
coalur
firewood
charcoal
any one of these
28624. The natural drying of bricks is also called back drying.
true
false
28625. The compressive strength of paving bricks should not be less than-
20 MN/m²
30 MN/m²
40 MN/m²
50 MN/m²
28626. For one cubic metre of brick masonry, the number of bricks required is-
400
450
500
550
28627. The average out-turn of first class bricks in kiln burning is-
50 to 60%
60 to 70%
70 to 80%
80 to 90%
28628. The main constituent of Portland cement is-
lime
iron oxide
alumina
alkalies
28629. The commonly used lime in white washing is---
quick lime
fat lime
lean lime
hydraulic lime
28630. The initial setting time of rapid hardening cement should not be less than--
30 min
4 hours
1 hour
10 hours
28631. The compressive strength of perforated bricks should not be less than-
4 MN/m²
5 MN/m²
6 MN/m²
7 MN/m²
28632. The final setting time of ordinary cement should not be more than-
2 hours,
4 hours
4 hours
10 hours
28633. The size of mould for bricks should be---- the specified size of the bricks.
equal to
double
smaller than
larger than
28634. The amount of gypsum usually added in the manufacture of cement is-
0.5 to 1%
3 to 5%
1 to 3%
0.1 to 0.5%
28635. The frog of a brick is normally made on its-
longer face
bottom face
shorter face
top face
28636. Lime occurs in a free state in nature.
True
False
28637. The average out-turn of first class bricks in clamp burning is about-
50%
60%
70%
80%
28638. The burning of bricks in kilns is completed within-----hours.
12
24
48
96
28639. The percentage of the slag component of Portland-slag cement varies from-
10 to 40%
70 to 80%
40 to 70%
80 to 90%
28640. The cementing property in cement is mainly due to---
lime
silica
iron oxide
alumina