Quiznetik

Concrete Technology and Design | Set 2

1. The maximum amount of dust which may be permitted in aggregates is

Correct : D. all the above

2. Bulking of sand is

Correct : D. swelling of sand when wetted

3. For a longitudinal reinforcing bar in a column, the minimum cover shall neither be less than the diameter of bar nor less than

Correct : D. 40 mm

4. Workability of concrete is measured by

Correct : B. slump test

5. The size of fine aggregates does not exceed

Correct : D. 4.75 mm

6. The main reason for providing number of reinforcing bars at a support in a simply supported beam is to resist in that zone

Correct : C. bond stress

7. The entrained air in concrete

Correct : A. increases workability

8. According to IS: 4561978, the flexural strength of concrete is

Correct : C. directly proportional to square root of compressive strength

9. Slump test is done for

Correct : D. concrete

10. Di-calcium silicate (C2S)

Correct : B. generates less heat of hydration

11. The limits of percentage p of the longitudinal reinforcement in a column is given by

Correct : C. 0.8% to 6%

12. The risk of segregation is more for

Correct : D. all the above

13. Le-Chatelier's apparatus is used for testing

Correct : A. soundness of cement

14. Construction joints are generally provided in concrete

Correct : D. all the above

15. If a grading curve is horizontal between the portions of 20 mm I.S. Sieve and 4.75 mm I.S. Sieve, the graded aggregates do not contain

Correct : D. all the above

16. Most common method of pre-stressing used for factory production is

Correct : A. long line method

17. C.R.R.I. charts are used to obtain a relationship between strength of concrete and

Correct : A. water cement ratio

18. For the design of retaining walls, the minimum factor of safety against overturning is taken as

Correct : B. 2.0

19. If the depth of moist sand in a cylinder is 15 cm and the depth of the sand when fully inundated with water is 12 cm, the bulking of the moist sand, is

Correct : D. 25 %

20. 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

21. If the foundations of all the columns of a structure are designed on the total live and dead load basis, then

Correct : C. the settlement of exterior columns will be more than interior columns

22. Saw dust can be rendered chemically inert by boiling it in water containing

Correct : A. ferrous sulphate

23. A concrete having a slump of 6.5 cm, is said to be

Correct : D. plastic

24. To obtain a very high strength concrete, use very fine grained

Correct : A. granite

25. Vicat apparatus is used for

Correct : B. consistency test

26. Which of the following losses of pre-stress occurs only in pre-tensioning and not in posttensioning?

Correct : A. elastic shortening of concrete

27. The type of aggregates of same nominal size, which contain less voids when compacted, are

Correct : A. rounded spherical

28. Pre-stress loss due to friction occurs

Correct : A. only in post-tensioned beams

29. Pick up the correct statement from the following:

Correct : D. all the above

30. In the method of voids for determination of the quantity of cement paste, it is assumed that

Correct : D. all the above

31. As compared to ordinary Portland cement, use of pozzolana cement

Correct : C. increases shrinkage

32. The following proportion of the ingredients of concrete mix, is not in conformation to arbitrary method of proportioning

Correct : D. 1 : 4 : 10

33. The strength and quality of concrete, depend upon:

Correct : D. all the above

34. The factor of safety for

Correct : B. steel is lower than that for concrete

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

Correct : D. 15 kg/cm2

36. Setting time of cement increases by adding

Correct : A. gypsum

37. According to IS: 4561978, the maximum reinforcement in a column is

Correct : C. 6 %

38. According to the recommendations of IS : 456-1978, the expansion joints

Correct : D. all the above

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

Correct : C. sodium carbonates and bicarbonates

40. If the size of panel in a flat slab is 6 m × 6 m, then as per Indian Standard Code, the widths of column strip and middle strip are

Correct : C. 3.0 m and 3.0 m

41. Pick up the incorrect statement from the following:

Correct : D. the mould is in the form of a frustum of hexagonal pyramid

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

Correct : C. hardness

43. While designing the pile as a column, the end conditions are nearly

Correct : C. one end fixed and other end hinged

44. The internal dimensions of a ware house are 15 m × 5.6 m, and the maximum height of piles is 2.70 m, the maximum number of bags to be stored in two piles, are

Correct : D. 3000 bags

45. Pick up the incorrect statement from the following. While performing preliminary test on concrete

Correct : D. concrete ingredients should be kept at a temperature of 37° ± 2°c

46. In a spherical dome the hoop stress due to a concentrated load at crown is

Correct : B. tensile everywhere

47. I.S. Sieve Nos. 10 mm and 4.75 mm are generally used for grading of

Correct : D. both (a) and (b)

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

Correct : C. abrasion resistance

49. The property of the ingredients to separate from each other while placing the concrete is called

Correct : A. segregation

50. Pick up the correct statement from the following:

Correct : D. all the above

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

Correct : A. 30 minutes

52. The strength of concrete after one year as compared to 28 days strength is about

Correct : C. 20 to 25% more

53. Specified compressive strength of concrete is obtained from cube tests at the end of

Correct : D. 28 days

54. Pick up the incorrect statement from the following:

Correct : D. tricalcium silicate (c3s) has more resistance to sulphate attack

55. If the permissible stress in steel in tension is 140 N/mm², then the depth of neutral axis for a singly reinforced rectangular balanced section will be

Correct : B. 0.40 d

56. A construction joint is provided where

Correct : D. all the above

57. Sand generally contains salt if it is obtained from:

Correct : C. sea beds

58. According to IS: 4561978, minimum slenderness ratio for a short column is

Correct : A. less than 12

59. Water cement ratio is

Correct : D. both (a) and (b) of the above

60. For a concrete mix 1:3:6 and water cement ratio 0.6 both by weight, the quantity of water required per bag, is

Correct : C. 14 kg

61. is the span)

Correct : C. l/7

62. Pick up the incorrect statement from the following:

Correct : C. in single size aggregates, bulk density is maximum

63. To prevent segregation, the maximum height for placing concrete, is

Correct : A. 100 cm

64. For a simply supported beam of span 15 m, the minimum effective depth to satisfy the vertical deflection limits should be

Correct : B. 750 mm

65. For compacting plain concrete road surface of thickness less than 20 cm, we use

Correct : B. screed vibrator

66. Expansion joints are provided if the length of concrete structures exceeds

Correct : D. 45 m

67. The permissible diagonal tensile stress in reinforced brick work is

Correct : A. about 0.1 n/mm²

68. Pick up the correct statement from the following:

Correct : D. all the above

69. Separation of water or water sand cement from a freshly concrete, is known

Correct : A. bleeding

70. The critical section for finding maximum bending moment for footing under masonry wall is located

Correct : C. halfway between the middle and edge of the wall

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

Correct : A. a horizontal line

72. High temperature

Correct : B. decreases the strength of concrete

73. Horizontal construction joints in concrete walls are generally provided at

Correct : D. all the above

74. Stress strain curve of high tensile steel

Correct : C. does not show definite yield point but yield point is defined by 0.2% proof stress

75. Addition of pozzolana to cement causes

Correct : D. all the above

76. Permissible compressive strength of M 200 concrete grade is

Correct : C. 200 kg/cm2

77. The minimum diameter of longitudinal bars in a column is

Correct : C. 12 mm

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

Correct : C. increased lime cement

79. Sand requiring a high water cement ratio, belongs to

Correct : A. zone i

80. Minimum grade of concrete to be used in reinforced concrete as per IS: 4561978 is

Correct : A. m 15

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

Correct : B. 5.0 cm

82. Non-uniform compaction may cause the concrete

Correct : D. all the above

83. Modulus of rupture of concrete is a measure of

Correct : A. flexural tensile strength

84. M10 grade of concrete approximates

Correct : A. 1 : 3 : 6 mix

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

Correct : D. thick and heavily reinforced

86. For a cantilever of effective depth of 0.5 m, the maximum span to satisfy vertical deflection limit is

Correct : A. 3.5 m

87. The bulk density of aggregates does not depend upon:

Correct : D. size and shape of the container

88. How long will it take for the concrete to achieve 100% of its strength?

Correct : D. 28 days

89. A higher modular ratio shows

Correct : B. lower compressive strength of concrete

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

Correct : D. 10 mm

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

Correct : D. all the above

92. The main reinforcement in the heel of a T-shaped R.C. retaining wall is provided on

Correct : A. top face perpendicular to wall

93. Separation of coarse aggregates from mortar during transportation, is known

Correct : C. segregation

94. A flaky aggregate is said to be elongated if its length is

Correct : B. twice the mean size

95. You are asked to construct a massive dam, the type of cement you will use, is

Correct : C. low heat cement

96. An ideal ware house, is provided

Correct : D. all the above

97. Normally pre-stressing wires are arranged in the

Correct : B. lower part of the beam

98. Pick up the correct statement from the following:

Correct : D. all the above

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

Correct : A. magnesium oxide

100. Poisson's ratio for concrete

Correct : B. increases with richer mixes