Quiznetik
Concrete Technology and Design | Set 4
1. Grading of sand causes great variation in
A. workability of concrete
B. strength of concrete
C. durability of concrete
D. all the above
Correct : D. all the above
2. The percentage of the aggregate of F.M. 2.6 to be combined with coarse aggregate of F.M. 6.8 for obtaining the aggregates of F.M. 5.4, is
A. 30 %
B. 40 %
C. 50 %
D. 60 %
Correct : C. 50 %
3. The ratio of various ingredients (cement, sand, aggregates) in concrete of grade M 200, is
A. 1 : 2 : 4
B. 1 : 3 : 6
C. 1 : 1½ : 3
D. 1 : 1 : 2
Correct : C. 1 : 1½ : 3
4. Joints in concrete structures, are provided
A. to reduce the tensile stresses likely to be developed due to evaporation of water
B. to minimise the change in the dimensions of the slab
C. to minimise the necessary cracking
D. all the above
Correct : D. all the above
5. For the construction of R.C.C. slabs, columns, beams, walls, etc. the grade of concrete mix used, is
A. 1 : 3 : 6
B. 1 : 1½ : 3
C. 1 : 2 : 4
D. 1 : 1 : 2
Correct : C. 1 : 2 : 4
6. Pick up the correct statement from the following:
A. water enables chemical reaction to take place with cement
B. water lubricates the mixture of gravel, sand and cement
C. strength of concrete structure largely depends upon its workability
D. all the above
Correct : D. all the above
7. The final operation of finishing floors, is known as
A. screeding
B. floating
C. trowelling
D. finishing
Correct : C. trowelling
8. Transport of concrete by pumps, is done for a distance of
A. 100 m
B. 200 m
C. 300 m
D. 400 m
Correct : D. 400 m
9. Curing
A. reduces the shrinkage of concrete
B. preserves the properties of concrete
C. prevents the loss of water by evaporation
D. all of the above
Correct : D. all of the above
10. The datum temperature for maturity by Plowman, is
A. 23°c
B. 0°
C. - 5.6°c
D. - 11.7°c
Correct : D. - 11.7°c
11. The bulk density of aggregates, is generally expressed as
A. tonnes/cubic metre
B. kg/cubic metre
C. kg/litre
D. g/cm3
Correct : C. kg/litre
12. For concreting tunnel linings, transportation of concrete is done by
A. pans
B. wheel borrows
C. containers
D. pumps
Correct : D. pumps
13. The factor which affects workability, is
A. water content and its temperature
B. shape and size of the aggregates
C. air entraining agents
D. all the above
Correct : D. all the above
14. Proper batching ensures
A. economy
B. durability
C. workability
D. all the above
Correct : D. all the above
15. The ratio of the length to breadth of a wooden float, is
A. 4.5
B. 5.5
C. 6.5
D. 7.5
Correct : D. 7.5
16. Vicat's apparatus is used for
A. fineness test
B. consistency test
C. setting time test
D. soundness test
Correct : B. consistency test
17. Percentage of pozzolanic material containing clay upto 80% used for the manufacture of pozzolana cement, is
A. 30 %
B. 40 %
C. 50 %
D. 60 %
Correct : A. 30 %
18. The grade of concrete not recommended by I.S. : 456, is
A. m 100
B. m 200
C. m 300
D. m 500
Correct : D. m 500
19. The compaction of concrete, improves
A. density
B. strength
C. durability
D. all the above
Correct : D. all the above
20. Segregation is responsible for
A. honey-combed concrete
B. porous layers in concrete
C. surface scaling in concrete
D. all the above
Correct : D. all the above
21. Slump test of concrete is a measure of its
A. consistency
B. compressive strength
C. tensile strength
D. impact value
Correct : A. consistency
22. If the effective working time is 7 hours and per batch time of concrete is 3 minutes, the output of a concrete mixer of 150 litre capacity, is
A. 15,900 litres
B. 16,900 litres
C. 17,900 litres
D. 18,900 litres
Correct : D. 18,900 litres
23. An ordinary Portland cement when tested for its fineness, should not leave any residue on I.S. sieve No. 9, more than
A. 5 %
B. 10 %
C. 15 %
D. 20 %
Correct : B. 10 %
24. The top diameter, bottom diameter and the height of a slump mould are:
A. 10 cm, 20 cm, 30 cm
B. 10 cm, 30 cm, 20 cm
C. 20 cm, 10 cm, 30 cm
D. 20 cm, 30 cm, 10 cm
Correct : A. 10 cm, 20 cm, 30 cm