Concrete Technology MCQ – Part 1

Concrete Technology MCQ:

Q. M10 grade of concrete approximates

a. 1 : 3 : 6 mix
b. 1 : 1 : 2 mix
c. 1 : 2 : 4 mix
d. 1 : 1.5 : 3 mix

Answer=> a

1. The strength and durability of concrete depends upon 

a. Size of aggregates 

b. Grading of aggregates 

c. Moisture contents of aggregates 

d. All of these 

Answer: d 

2. The workability of concrete is defined as the 

a. Ease with which it can be mixed, transported and placed in position in a homogeneous state. 

b. Breaking up of cohesion in a mass of concrete. 

c. Separation of water or water-cement mixture from the freshly mixed concrete. 

d. None of these. 

Ans: a 

3. The separation of water or water-cement mixture from the freshly mixed concrete is known 

a. Bleeding 

b. Segregation 

c. Shrinkage 

d. Creep 

Ans: a 

4. Bulking of sand is maximum if moisture content is about

a. 2%

b. 4%

c. 6%

d. 8%

Ans: b

5. If 1500 g of water is required to have a cement paste 1875 g of normal consistency, the percentage of water is

a. 20%

b. 25%

c. 30%

d. 40%

Ans: b

6. Wp and Wf are the weights of a cylinder containing partially compacted and fully compacted concrete. If the compaction factor 

is 0.95, the workability of concrete is

a. extremely low
b. Low
c. Medium
d. High

Ans: d

7. For given water content, workability decreases if the concrete aggregates contain an excess of

a. Thin particles
b. Flat particles
c. Elongated particles
d. Flaky particles

8. The strength and durability of concrete depends upon

a. Size of aggregates

b. Grading of aggregates

c. Moisture contents of aggregate

d. All of these

Ans: d

9. For ensuring quality of concrete, use

a. single sized aggregates

b. two sized aggregate

c. graded aggregates

d. Coarse aggregates

Ans: c

10. According to I.S. : 456, the number of grades of concrete mixes, is

a. 4

b. 5

c. 6

d. 7

Ans: d

11. The mixture of different ingredients of cement, is burnt at

a. 1000°C

b. 1200°C

c. 1400°C

d. 1600°C

Ans: c

12. The risk of segregation is more for

a. wetter mix

b. larger proportion of maximum size aggregate

c. coarser grading

d. All of these

Ans: d

13. Workability of concrete is directly proportional to

a. Aggregate cement ratio

b. Time of transist

c. Grading of aggregates

d. All the above

Ans: c

14.For concreting of heavily reinforced sections without vibration, the workability of concrete expressed as compacting factor should be

a. 0.75 – 0.80

b. 0.80 – 0.85

c. 0.85 – 0.90

d Above 0.92

Ans: d

15. For road pavements, the cement generally used, is

Ordinary portland cement

Rapid hardening cement

Low heat cement

d. Blust furnace slag cement

Ans: b

16. Addition of pozzolana to ordinary port land cement, causes

decreases in early strength

b. Increase in shrinkage

c. Decreases in chemical action with sulfate

d. All the above

Ans: d

 17. For construction of structures in sea water, the cement generally preferred to, is

a. Portland pozzolana cement

b Rapid hardening cement

c. Low heat cement

d High alumina cement

Ans: A

18. Curing of pavements, floors, roofs and slabs, is done by

a. Membrane curing method

b. Ponding method

c. Covering surface with gunny bags

d. Sprinkling method

Ans: b

19. The bulk density of aggregates, depends upon

a. Shape

b. Grading

c. Compaction

d. All the above

Ans: d

20. The main object of compaction of concrete, is:

a. To eliminate air holes

b. To achieve maximum density

c. To provide intimate contact between concrete and embedded materials

d. All of these

Ans: d

21. After casting, an ordinary cement concrete on drying

a. Expands

b. Mix

c. Shrinks

d. None of these

Ans: c

22. The standard sand now a days used in India, is obtained from

a. Jaipur (Rajasthan)

b. Ennore (Madras)

c. Hyderabad (Andhra Pradesh)

d. Jullundur (Punjab)

Ans: b

23. 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

Ans: d

24. While compacting the concrete by a mechanical vibrator, the slump should not exceed

a. 2.5 cm

b. 5 cm

c. 7.5 cm

d. 10 cm

Ans: b

25. An aggregate is said to be flaky if its least dimension is less than

a. 1/5th of mean dimension

b. 2/5th of mean dimension

c. 3/5th of mean dimension

d. 4/5th of mean dimension

Ans: c

26. The ratio of the length to breadth of a wooden float, is

a. 4.5

b. 5.5

c. 6.5

d. 7.5

Ans: d

27. The commonly used material in the manufacture of cement is

a. Graphite

b. Slate

c. Lime stone

d. Sand stone

Ans: c

28. For the construction of cement concrete floor, the maximum permissible size of aggregate, is

a. 4 mm

b. 6 mm

c. 8 mm

d. 10 mm

Ans: d

29. The process of proper and accurate measurement of concrete ingredients for uniformity of proportion, is known

a. Grading

b. Mixing

c. Batching

d. Curing

Ans: c

30. The preliminary test is repeated if the difference of compressive strength of three test specimens, exceeds

a. 5 kg/cm2

b. 10 kg/cm2

c. 12 kg/cm2

d. 15 kg/cm2

Ans: d

31. Pick up the correct proportions of chemical ingredients of cement

a. Lime : Silica : Alumina : Iron oxide : 63 : 22 : 6 : 3

b. Silica : Lime : Alumina : Iron oxide : 63 : 22 : 6 : 3

c. Alumina : Silica : Lime : Iron oxide : 63 : 22 : 6 : 3

d. Iron oxide : Alumina : Silica : Lime : 63 : 22 : 6 : 3

Ans: a

32. Transporting of concrete by pumps, is done for a distance of

a. 100 m

b. 200 m

c. 300 m

d. 400 m

Ans: d

33. The high strength of rapid hardening cement at early stage, is due to its

a. finer grinding

b. burning at high temperature

c. increased lime cement

d. higher content of tricalcium

Ans: c

34. Vicat’s apparatus is used for

a. fineness test

b. Consistency test

c. Compressive strength test

d. Soundness test

Ans: b

35. M 150 grade of concrete approximates

a. 1:2:3

b. 1 : 3 : 6

c. 1:1:2

d. 1:2:4

Ans: c

36. Internal friction between the ingredients of concrete, is decreased by using

a. less water

b. fine aggregates

c. fine mix

d. More water and coarse aggregates

Ans: d

37. The entrained air in concrete

a. increases workability
b. decreases workability
c. decreases resistance to weathering
d. increases strength

Ans: a

38. In slump test, each layer of concrete is compacted by a steel rod 60 cm long and of 16 mm diameter for

a. 20 times

b. 25 times

c. 30 times

d. 40 times

Ans: b

39. Concrete gains strength due to

a. Chemical reaction of cement and aggregates

b. Evaporation of cement from concrete

c. Hydration of cement

d. All the above

Ans: c

40. To determine the modulus of rupture, the size of test specimen used is

a. 150 x 150 x 500 mm

b. 100 x 100 x 700 mm

c. 150 x 150 x 700 mm

d. 100 x 100 x 500 mm

Ans: c

41.  A concrete having a slump of 65 cm, is said to be

a. dry
b. earth moist
c. semi-plastic
d. plastic

Ans: d

42. Concrete is unsuitable for compaction by a vibrator if it is

a. dry
b. earth moist
c. semi-plastic
d. plastic

Ans: d

43. Pick up the incorrect statement from the following :

a. Admixtures accelerate hydration
b. Admixtures make concrete water proof
c. Admixtures make concrete acid proof
d. Admixtures give high strength

Ans: a

44. The rock which is not calcareous, is :

a. lime stone
b. macl
c. chalk
d. laterite

Ans: d

45. The minimum percentage of chemical ingredient of cement is that of

a. magnesium oxide
b. iron oxide
c. alumina
d. lime

Ans: a

46. Efflorescence im cement is caused dim to an excess of

a. alumina
b. inin oxide
c. silica
d. alkalis

Ans: d

47. Pick up the incorrect statement from the following :

a. Tricalcium silicate (C3S) hydrates rapidly
b. Tricalcium silicate (C3S) generates more heat of hydration
c. Tricalcium silicate (C3S) develops early strength
d. Tricalcium silicate (C3S) has more resistance to sulphate attack

Ans: d

48. Di-calcium silicate (C2S)

a. hydrates rapidly
b. generates less heat of hydration
c. hardens rapidly
d. provides less ultimate strength to cement

Ans: b

49. Tricalcium aluminate (C3A)

a. reacts fast with water
b. generates less heat of hydration
c. causes initial setting and early strength of cement
d. does not contribute to develop the ultimate strength

Ans: b

50. The high strength of rapid hardening cement at early stage, is due to its

a. finer grinding
b. burning at high-temperature
c. increased lime cement
d. higher content of tricalcium

Ans: c

51. to construct a massive dam, the type of cement you will use, is

a. ordinary Portland cement
b. rapid hardening cement
c. low heat cement
d. blast furnace slag cement

Ans: c

52.  For the construction of thin RCC structures, the type of cement to be avoided, is

a. ordinary Portland cement
b. rapid hardening cement
c. low heat cement
d. blast furnace slag cement

Ans: d

53.A concrete using an air entrained cement

a. has strength less than 10% to 15%
b. has more resistance to weathering
c. is more plastic and workable
d. is free from segregation and bleeding

Answer=> c

54. Percentage of pozzolanic material containing clay upto 80% used for the manufacture of pozzolana cement, is

a. 30%
b. 40%
c. 50%
d. 60%

Answer=> a

55. 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 nom to 50 mm
d. 50 trim to 60 mm

Answer=> c

56. An aggregate is known as cyclopean aggregate if its size is more than

a. 475 mm
b. 30 mm
c. 60 mm
d. 75 mm

Answer => D

57. If aggregates completely pass through a sieve of size 75 mm and are retained on a sieve of size 60 mm, the particular aggregate will be flaky if its minimum dimension is less than

a. 205 mm
b. 305 mm
c. 405 mm
d. 505 mm

Answer => C

58. If fineness modulus of sand is 25, it is graded as

A. very fine sand
B. fine sand
C. medium sand
D. coarse sand

Answer=> b

59. The impurity of mixing water which affects the setting time and strength of concrete, is

a. sodium sulphates
b. sodium chlorides
c. sodium carbonates and bicarbonates
d. calcium chorides

Answer => c

60. Water cement ratio is

a. volume of water to that of cement
b. weight of water to that of cement
c. weight of concrete to that of water
d. both A and B of the above

Answer => d

61. ISI has specified the full strength of concrete after

a. 7 days
b. 14 days
c. 21 days
d. 28 days

Answer => d

62. 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=> b

63. Water required per bag of cement, is

a. 7 kg
b. 14 kg
c. 21 kg
d. 35 kg

Answer=> d

64. Higher workability of concrete is required if the structure is

a. made with cement concrete
b. thick and reinforced
c. thin and heavily reinforced
d. thick and heavily reinforced

Answer => d

65. 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

Answer => a

66. If the slump of a concrete mix is 60 mm, its workability is

a. very low
b. low
c. medium
d. high

Answer=> c

67. For the construction of RCC slabs, columns, beams, walls, etc the grade of concrete mix used, is

a. 1 :3 :6
b. 1 : I: 3
c. 1 :2 :4
d. 1 : 1 :2

Answer => c

68.  For the construction of the retaining structures, the type of concrete mix to be used, is

a. 1: 3 : 6
b. 1 : 2 : 4
c. 1: 1: 3
d. 1 : 1 : 2

Answer=>

69. If the deptl-eof moist sand in a cylinder is 15 cr the depth of the sand when fully inundated with watel cm, the bulking of the moist sand, is

a. 10%
b. 12%
c. 15%
d. 25%

Answer => D

70. 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 : 1: 2
D. 1 : 1 : 2

Answer=> c

71. The 28 days cube strength of mass concrete using aggregates of maximum size 5 cm for gravity dams should be

A. between 150 to 300 kg/cm2
B. between 350 to 600 kg/cm2
C. between 150 to 500 kg/cm2
D. below 200 kg/cm2

Answer=> d

72. Ware house pack’ of cement means

a. full capacity of the ware house
b. pressure exertion of the bags of upper layers
c. pressure compaction of the bags on lower layers
d. packing the ware house

Answer => C

73. The process of mixing, transporting, placing and compacting concrete using Ordinary Port land Cement should not take more than

A. 30 minutes
B. 40 minutes
C. 60 minutes
D. 75 minutes

Answer => a

74. For concreting tunnel linings, tranportation of concrete is done by

a. pans

b. wheel borrows

c. containers

d. pumps

Answer=> d

75. To prevent segregation, the maximum height for placing concrete, is
a. 100 cm

b. 125 cm

c. 150 cm

d. 200 cm

Answer=> a

76. The process of hardening the concrete by keeping its surface moist is known

a. Placing

b. Wetting

c. Curing

d. Compacting

Answer => c

77. For the construction of cement concrete dams, the maximum permissible size of the aggregates, is

a. 40 mm

b. 50 mm

c. 60 mm

d. 70 mm

Answer=> a

78. Particles of 0.002 mm size are that of

a. clay

b. sand

c. Gravel

d. none of these

Answer=> a

79. The percentage of voids in cement is approximately

a. 25%

b. 40%

c. 60%

d. 80%

Answer=> b

80. According to Whitneys theory, the ultimate strain of concrete is assumed as

a. 0.03%

b. 0.1%

c. 0.3%

d 3 %

Answer=> c

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