Civil Engineering - Concrete Technology MCQs Part 3
1. Permissible compressive strength of M 150 concrete grade is
A.
100 kg/cm2
100 kg/cm2
B.
150 kg/cm2
150 kg/cm2
C.
200 kg/cm2
200 kg/cm2
D.
250 kg/cm2
250 kg/cm2
E.
300 kg/cm2
300 kg/cm2
Answer Option B
2. Slump test of concrete is a measure ofits
A.
consistency
consistency
B.
compressive strength
compressive strength
C.
tensile strength
tensile strength
D.
impact value.
impact value.
Answer Option A
3. Pozzolana cement is used with confidence for construction of
A.
dams
dams
B.
massive foundations
massive foundations
C.
abutments
abutments
D.
R.C.C. structures
R.C.C. structures
E.
all the above.
all the above.
Answer Option E
4. Water cement ratio is
A.
volume of water to that of cement
volume of water to that of cement
B.
weight of water to that of cement
weight of water to that of cement
C.
weight of concrete to that of water
weight of concrete to that of water
D.
volume of concrete to that of water
volume of concrete to that of water
E.
both (a) and (b) of the above.
both (a) and (b) of the above.
Answer Option E
5. Efflorescence in cement is caused due to an excess of
A.
alumina
alumina
B.
iron oxide
iron oxide
C.
silica
silica
D.
alkalis
alkalis
E.
magnesium oxide.
magnesium oxide.
Answer Option D
6. If the engineer-in-charge approves, the 10 cm cubes may be used for the work test of concrete provided maximum nominal size of aggregate, does not exceed
A. 10 cm
B. 15 cm
C. 20 cm
D. 25 cm
E. 30 cm
Answer Option C
7. The diameter of the Vicat plunger is 10 mm and its length varies from
A. 20 mm to 30 mm
B. 30 mm to 40 mm
C. 40 mm to 50 mm
D. 50 mm to 60 mm
E. none of these.
Answer Option C
8. The shrinkage of concrete
A. is proportional to water content is the mix
B. is proportional to cement concrete
C. increases with age of concrete
D. all the above.
Answer Option D
9. 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 : : 3
D. 1 : 1 : 2
E. 4 : 2 : 1
Answer Option C
10. Separation of water or water sand cement from a freshly concrete, is known
A. bleeding
B. creeping
C. segregation
D. flooding
E. none of these.
Answer Option A
11. Slump test of concrete is a meausre ofits
A. consistency
B. compressive strength
C. tensile strength
D. impact value.
Answer Option A
12. According to Water-Cement Ratio Law, the strength of workable plastic concrete
A. depends upon the amount of water used in the mix
B. does not depend upon the quality of cement mixed with aggregates
C. does not depend upon the quanity of cement mixed with aggregates
D. all the above.
Answer Option D
13. Pick up the incorrect statement from the following:
A. In properly graded aggregates, bulk density is more
B. In single size aggregates, bulk density is least
C. In single size aggregates, bulk density is maximum
D. None of these.
Answer Option C
14. Saw dust can be rendered chemically inert by boiling it in water containing
A. ferrous sulphate
B. potassium chloride
C. ammonia
D. nitric acid
E. sulphuric acid.
Answer Option A
15. Pick up the correct statement from the following:
A. High percentage of C3S and low percentage of C2S cause rapid hardening
B. High percentage of C3S and low percentage of C2S make the cement less resistive to chemical attack
C. Low percentage of C3S and high percentage of C2S contribute to slow hardening
D. Low percentage of C3S and high percentage of C2S provide greater resistance to chemical attack
E. All the above.
Answer Option E
16. The factor which affects workability, is
A. water content and its temperature
B. shape and size of the aggregates
C. grading and surface textures of the aggregates
D. air entraining agents
E. all the above.
Answer Option E
17. The cement whose strength is a little lower than the ordinary cement during the first three months but attains afterwards the same strength, is known as
A. low-heat Portland cement
B. rapid hardening Portland cement
C. Portland blast slag cement
D. Portland pozzolana cement
E. none of these.
Answer Option A
18. Pick up the correct statement from the following:
A. Sand stones may be divided into calcareous, siliceous and ferrugineous sand stones
B. Concrete using sand stones, cracks due to excessive shrinkage
C. Very hard and close grained crystallined lime stones are suitable aggregates but provide low strength
D. Broken bricks produce a concrete having good fire resisting qualities
E. All the above.
Answer Option E
19. 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. Only a small quantity of water is required for hydration of cement
D. Strength of concrete structure largely depends upon its workability
E. All the above.
Answer Option E
20. Pick up the incorrect statement applicable to the field test of good cement.
A. When one thrusts one's hand into a bag of cement, one should feel warm
B. The colour of the cement is bluish
C. A handful of cement thrown into a bucket of water should sink immediately
D. By rubbing cement in between fingers, one should feed rough
E. All the above.
Answer Option E
21. Pick up the correct statement from the following:
A. Calcium chloride acts as a retarder
B. Gypsum (calcium sulphate) acts as an accelerator
C. Gypsum (calcium sulphate) acts as a retarder
D. Calcium chloride acts as an accelerator
E. Both (c) and (d).
Answer Option E
22. 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.
Answer Option D
23. 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
Answer Option D
24. The condition not applicable to water cement ratio law, is
A. internal moisture conditions on hydration continue till complete strength is gained
B. concrete specimens may be tested at any temperature
C. concrete specimens need be of same age
D. concrete specimens need be of same size
E. none of these.
Answer Option B
25. High temperature
A. increases the strength of concrete
B. decreases the strength of concrete
C. has no effect on the strength of concrete
D. none of these.
Answer Option B
26. The bulk density of aggregates, is generally expressed as
A. tonnes/cubic metre
B. kg/cubic metre
C. kg/litre
D. g/cm3
E. none of these.
Answer Option C
27. The grade of concrete M 150 means that compressive strength of a 15 cm cube after 28 days, is
A. 100 kg/cm2
B. 150 kg/cm2
C. 200 kg/cm2
D. 250 kg/cm2
E. 300 kg/cm2
Answer Option B
28. Allowable shear strength of concrete, depends upon
A. shear strength
B. tensile strength
C. compressive strength
D. none of these.
Answer Option A
29. The most useless aggregate is one whose surface texture is
A. smooth
B. granular
C. glassy
D. honey combed and porous.
Answer Option C
30. To obtain a very high strength concrete, use very fine grained
A. Granite
B. Magnetite
C. Barite
D. Volcanic scoria.
Answer Option A
31. Concrete containing
A. silicious aggregates, has higher co-efficient of expansion
B. igneous aggregates, has intermediate coefficient of expansion
C. lime stones, has lowest co-efficient of expansion
D. All the above.
Answer Option D
32. An ordinary Portland cement when tested for its fineness, should not leave any residue on I.S. seive No. 9, more than
A. 5%
B. 10%
C. 15%
D. 20%
E. 25%
Answer Option B
33. 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
E. 30 cm, 20 cm, 10 cm
Answer Option A
34. Workability of concrete mix with low water cement ratio is determined by
A. tensile strength test
B. slump test
C. compaction factor test
D. flexural strength test
E. none of these.
Answer Option C
35. While designing an air entrained concrete
A. water cement ratio is reduced
B. proportion of aggregates is reduced
C. an allowance for the entrained air is made
D. strength of the concrete, is reduced
E. all the above.
Answer Option E
36. Pick up the incorrect statemnt from the following. For performing compressive strength test of cement
A. cement and standard sand mortar are used in the ratio of 1 : 3
B. water is added at the rate of + 3.0 percentage of water where P is the percentage of water for standard consistency
C. A cube mould of 10 cm x 10 cm x 10 cm is used
D. The perpared moulds are kept in a atmosphere of 50% relative humidity
E. The temperature of water in the submerged tank for curing moulds, should be 27° ± 2°C.
Answer Option A
37. For concreting tunnel linings, tran-portation of concrete is done by
A. pans
B. wheel borrows
C. containers
D. pumps
E. belt conveyors.
Answer Option D
38. The operation of removing humps and hollows of uniform concrete surface, is known as
A. floating
B. screeding
C. trowelling
D. finishing
E. none of these.
Answer Option B
39. The void ratio of
A. single size coarse aggregate is roughly 0.45.
B. graded coarse aggregate is roughly 0.040
C. fine aggregate is roughly 0.45
D. all the above.
Answer Option D
40. The type of aggregates not suitable for high strength concrete and for pavements subjected to tension, is
A. rounded aggregate
B. irregular aggregate
C. angular aggregate
D. flaky aggregate
E. none of these.
Answer Option A
41. 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 : : 3
C. 1 : 2 : 4
D. 1 : 1 : 2
E. 1 : 4 : 8.
Answer Option C
42. The type of aggregates of same nominal size, which contain less voids when compacted, are
A. rounded spherical
B. irregular
C. flaky
D. none of these.
Answer Option A
43. For the construction of cement con-certe dams, the maximum permissible size of the aggregates, is
A. 40 mm
B. 50 mm
C. 60 mm
D. 70 mm
E. 80 mm
Answer Option A
44. Permissible compressive strength of M 200 concrete grade is
A. 100 kg/cm2
B. 150 kg/cm2
C. 200 kg/cm2
D. 250 kg/cm2
E. 300 kg/cm2
Answer Option C
45. For preparing a test-specimen, it is necessary
A. to mix cement and fine aggregate by dry hand
B. to mix coarse aggregates
C. to mix water to the cement, fine aggregates and coarse aggregates
D. to oil inner surface of the mould and the base plate, before placing concrete
E. all the above.
Answer Option E
46. The aggregate containing moisture in pores and having its suface dry, is known as
A. moist aggregates
B. very dry aggregates
C. dry aggregates
D. saturated surface dry aggregate
E. none of these.
Answer Option D
47. The commercial name of white and coloured cement in India, is
A. colocrete
B. rainbow cement
C. silvicrete
D. snowcem
E. all the above.
Answer Option E
48. Pick up the correct statement from the following:
A. An increase in water content must be accompanied by an increase in cement content
B. Angular and rough aggregates reduce the workability of the concrete
C. Large size aggregates increase the workability due to lesser surface area
D. The slump of the concrete mix decreases due to an increase in temperature
E. All the above.
Answer Option E
49. To hydrate 500kg of cement full water needed, is
A. 100 kg
B. 110 kg
C. 120 kg
D. 130 kg
E. 140 kg
Answer Option D
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