Quiznetik

Concrete Technology | Set 1

1. Processes of cement manufacturing is…….?

Correct : D. All of above

2. After 28 days of curing, cement gains have been found to have hydrated to a depth of only…..u.

Correct : C. 4

3. Total…….. % of water by weight of water by weight of cement is required for complete hydration.

Correct : B. 38

4. Hydration of cement is due to chemical action of water with

Correct : D. All the above.

5. Proper proportioning of concrete, ensures

Correct : D. all the above

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

Correct : C. 3/5th of mean dimension

7. A small quantity of …………. % of gypsum is added to prevent flash-setting of the cement.

Correct : B. 2 to 3

8. Highest oxide composition present in cement is……

Correct : D. Lime

9. First 7 days strength in cement is due to….. Bogue compound.

Correct : A. C3S

10. Heat of hydration of C3S at 90 days is ………. cal/g

Correct : B. 104

11. …………refers to the gain of strength of a set cement paste.

Correct : B. Hardening of cement

12. For long time storage ……..cement used.

Correct : C. Hydrophobic

13. Repair of air-field pavement use……

Correct : B. Very high Strength cement

14. Note more than ……. bags should be kept one above other.

Correct : C. 14

15. For Fineness test ……. micron sieve is use.

Correct : D. 90

16. The weight of residue should not exceed ……. for OPC.

Correct : A. 10 %

17. For consistency test vicat plunger having ……. dia and …….. Length is used.

Correct : B. 10 mm & 50 mm

18. For OPC Value of IST And FST is…… .

Correct : A. 30 m & 600 m

19. For compressive strength test of cement ………. water is added.

Correct : C. p/4 + 3

20. Undesirable expansion of some of constituents of cement after setting is known as……… .

Correct : B. unsoundness

21. Density of light weight aggregate concrete is about …….. kg/m3 .

Correct : C. 1200

22. Material between…………… is classified as silt.

Correct : D. 0.06 mm to 0.002 mm

23. Angular aggregate having percentage of voids ranging from……….

Correct : C. 38 to 40

24. In crushing value test of aggregate, gradually compressive load of….. Tons is apply.

Correct : A. 40

25. Specific gravity of natural aggregate lie between……

Correct : C. 2.6 to 2.8

26. Coarse aggregates absorbs…….. % of moisture.

Correct : B. 0.5 to 1

27. To control alkali aggregate reaction restricting alkali content in cement below……%

Correct : D. 0.6

28. If the actual grading curve is steeper than the specified grading curve, it indicates an excess of ……..particle size.

Correct : C. medium

29. Fineness modulus of fine sand is…… .

Correct : A. 2.2 – 2.6

30. Permissible limit organic solids in water is……..mg/l

Correct : C. 200

31. Bigger size of aggregate will give higher workability.

Correct : A. True

32. To measure workability of concrete in field …………….test is used.

Correct : C. Slump test

33. Steel tamping rod of 0.6m length and 16 mm diameter is used for tamping of concrete.

Correct : B. True

34. Types of slump is…..

Correct : D. All of above

35. 25 to 75 mm workability of concrete, indicate

Correct : C. Low workability

36. In very low category of degree of workability determination by compacting factor will be more appropriate.

Correct : A. True

37. Compacting factor test should be made for concrete with maximum size of aggregate not exceeding 40 mm.

Correct : A. True

38. The value of flow % may range anything from 0 to …. %

Correct : D. 150

39. Separating out of the ingredients of concrete mix from concrete is known as……… .

Correct : A. Segregation

40. Water from concrete comes out to the surface of the concrete is known as……….

Correct : B. bleeding

41. Main causes of bleeding :

Correct : D. All of this

42. The formation of cement paste at the surface is known as laitance.

Correct : A. True

43. Workability of concrete is……. to the w/c.

Correct : A. proportional

44. Workability of concrete is …….to the strength of concrete.

Correct : B. inversely proportional

45. Good method for proportioning the materials.

Correct : A. Weight batching

46. In Volume batching 1 bag cement =

Correct : A. 35 lit

47. In volume batching………. % of bulking is take into account.

Correct : C. 20

48. Density of water is 1 kg/liter.

Correct : A. True

49. In hand mixing …….. % more cement is added in mix.

Correct : D. 10

50. Concrete mixer are generally designed to run at a speed of ……….. Revolution per minute.

Correct : C. 15 to 20

51. For proper mixing about…………. revolution are required.

Correct : D. 25 to 30

52. The process of mixing, transporting, placing and compacting concrete should not take more than ……. min any case.

Correct : A. 90

53. Commonly use retarders is……

Correct : D. All of the above

54. Inert material of a cement concrete mix, is

Correct : C. aggregate

55. Placing of concrete should preferably be done at a temperature of

Correct : D. 27 ± 2°C

56. The aggregate impact value of the aggregate used in

Correct : D. all the above.

57. On a grading curve, the gap grading is represented by

Correct : A. a horizontal line

58. Bulking of sand is

Correct : D. swelling of sand when wetted

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

Correct : B. ponding method

60. Pick up the incorrect statement from the following:

Correct : A. With passage of time, the strength of cement increases

61. The surface where two successive placements of concrete meet, is known as

Correct : C. Construction joint

62. An excess of flaky particles in concrete aggregates

Correct : D. all the above

63. I.S.I. has specified the full strength of concrete after

Correct : D. 28 days

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

Correct : A. magnesium oxide

65. The specifications of a cement bag for storage, are

Correct : D. all the above

66. The bulk density of aggregates, depends upon

Correct : D. all the above.

67. The concrete mix which causes difficulty in obtaining a smooth finish, possess

Correct : C. harshness

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

Correct : D. 75 mm

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

Correct : D. all the above

70. Concrete gains strength due to

Correct : C. hydration of cement

71. 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

Correct : C. 40.5 mm

72. Log Angles machine is used to test the aggregate for

Correct : C. abrasion resistance

73. Pozzolanic properties exist in

Correct : D. all the above

74. Workability improved by adding

Correct : D. all the above

75. If the various concrete ingredients i.e. cement, sand and aggregates are in the ratio of 1:3:6, the grade of concrete, is

Correct : A. M 10

76. Gypsum is added for

Correct : C. controlling setting time

77. Cement used for normal concrete construction, is obtained by burning a mixture of

Correct : D. silicious, argillaceous and calcareous materials

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

Correct : B. 25 times

79. Efflorescence in cement is caused due to an excess of

Correct : D. alkalis

80. Slump test of concrete is a measure of its

Correct : A. consistency

81. Pick up the incorrect statement applicable to the field test of good cement.

Correct : D. All the above

82. The most useless aggregate is one whose surface texture is

Correct : C. glassy

83. The top diameter, bottom diameter and the height of a slump mould are :

Correct : A. 10 cm, 20 cm, 30 cm

84. For concreting tunnel linings, transportation of concrete is done by

Correct : D. pumps

85. Admixture which cause early setting and hardening of concrete are called …

Correct : B. accelerators

86. As compared to ordinary Portland cement, high alumina cement has

Correct : A. higher initial setting time but lower final setting time

87. Maximum permissible limit of magnesia content in OPC is…

Correct : B. 6%

88. Reduction in the quantity of mixing water which is possible by the use of plasticizers and admixture varies from

Correct : B. 5% to 15%

89. Which of the following types of concrete mixture is most commonly used in precast concrete factories?

Correct : B. pan type mixer

90. According to IS : 456-1978 minimum period stipulated for most curing of concrete using ordinary Portland cement is

Correct : B. 7 days

91. For reinforced concrete exposed to sulphate attack minimum grade required is

Correct : C. M20

92. The deterioration of concrete take place due to.

Correct : D. All of the above

93. Cement content should be such that concrete has sufficient alkalinity (PH value).

Correct : A. True

94. For sea water concreting …………. cement shall be used.

Correct : D. All of above

95. Durability of concrete can be improved by impregnation of …………… in the voids of concrete.

Correct : A. polymer

96. What do you mean by admixtures?

Correct : A. Ingredients which are added to in cement before or after concrete mix

97. Super plasticizers reduce water requirement by ___________ %.

Correct : A. 12-30

98. Damp proofing is done with a __________ based mixture.

Correct : B. Tar

99. What is water proofing admixtures?

Correct : A. Water repellent materials

100. Which one is not a chemically active pore filling material?

Correct : B. Aluminium