Quiznetik

Concrete Technology and Design | Set 1

1. The temperature reinforcement in the vertical slab of a T-shaped R.C. retaining wall is

Correct : D. provided more on front face than on inner face

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

Correct : B. 4 %

3. Diagonal tension in a beam

Correct : C. increases below the neutral axis and decreases above the neutral axis

4. According to IS: 4561978, the column or the strut is the member whose effective length is greater than

Correct : C. 3 times the least lateral dimension

5. When shear stress exceeds the permissible limit in a slab, then it is reduced by

Correct : A. increasing the depth

6. The diameter of ties in a column should be

Correct : D. more than 5 mm and also more than one-fourth of diameter of main bar

7. In counterfort retaining walls, the main reinforcement in the stem at support is

Correct : B. provided only on inner face

8. Due to shrinkage stresses, a simply supported beam having reinforcement only at bottom tends to

Correct : A. deflect downward

9. The purpose of reinforcement in pre-stressed concrete is

Correct : C. to impart initial compressive stress in concrete

10. Select the correct statement

Correct : A. elastic modulus of high tensile steel is nearly the same as that of mild steel

11. Due to circumferential action of the spiral in a spirally reinforced column

Correct : D. both the capacity of column and ductility of column increase

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

Correct : D. above 0.92

13. Workability of concrete is directly proportional to

Correct : C. grading of the aggregate

14. Critical section for shear in case of flat slabs is at a distance of

Correct : B. d/2 from periphery of column/capital/ drop panel

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

Correct : B. rapid hardening cement

16. Pick up the incorrect statement from the following:

Correct : D. none of these

17. For a slab supported on its four edges with corners held down and loaded uniformly, the Marcus correction factor to the moments obtained by Grashoff Rankine's theory

Correct : A. is always less than 1

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

Correct : D. all the above

19. Pick up the correct statement from the following:

Correct : D. all the above

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

Correct : A. portland-pozzolana cement

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

Correct : B. ponding method

22. Pick up the correct statement from the following:

Correct : D. all the above

23. The bulk density of aggregates, depends upon

Correct : D. all the above

24. In symmetrically reinforced sections, shrinkage stresses in concrete and steel are respectively

Correct : B. tensile and compressive

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

Correct : D. all the above

26. Which of the following has high tensile strength?

Correct : B. cold drawn wires

27. Concrete gains strength due to

Correct : C. hydration of cement

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

Correct : C. 150 × 150 × 700 mm

29. Tricalcium aluminate (C3A)

Correct : B. generates less heat of hydration

30. 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 100

31. Admixtures which cause early setting and hardening of concrete are called

Correct : B. accelerators

32. Pick up the correct statement from the following:

Correct : D. all the above

33. Pick up the incorrect statement from the following:

Correct : A. admixtures accelerate hydration

34. For a reinforced concrete section, the shape of shear stress diagram is

Correct : C. parabolic above neutral axis and rectangular below neutral axis

35. Allowable shear strength of concrete, depends upon

Correct : A. shear strength

36. 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

37. The individual variation between test strength of sample should not be more than

Correct : C. ± 15 % of average

38. Pick up the incorrect statement from the following:

Correct : D. all the above

39. The slab is designed as one way if the ratio of long span to short span is

Correct : D. greater than 2

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

Correct : A. 40 mm

41. Pick up the incorrect statement from the following:

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

42. To hydrate 500kg of cement full water needed, is

Correct : D. 130 kg

43. Pick up the correct statement from the following:

Correct : D. all the above

44. In a counterfort retaining wall, the main reinforcement in the stem at mid span is provided on

Correct : A. front face only

45. Under normal conditions using an ordinary cement, the period of removal of the form work, is:

Correct : D. all the above

46. Water cement ratio is generally expressed in volume of water required per

Correct : D. 50 kg

47. To ensure constant moisture content in aggregates

Correct : D. all the above

48. Pick up the correct statement from the following:

Correct : D. all the above

49. The average permissible stress in bond for plain bars in tension is

Correct : B. increased by 25% for bars in compression

50. Concrete mainly consists of

Correct : D. all the above

51. For the construction of thin R.C.C. structures, the type of cement to be avoided, is

Correct : D. blast furnace slag cement

52. Which of the following R.C. retaining walls is suitable for heights beyond 6 m?

Correct : C. counterfort type

53. For batching 1:3:6 concrete mix by volume, the ingredients required per bag of 50 kg cement, are:

Correct : D. 105 litres of sand and 210 litres of aggregates

54. A concrete using an air entrained cement

Correct : C. is more plastic and workable

55. Pick up the correct statement from the following:

Correct : D. none of these

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

Correct : C. construction joint

57. A beam curved in plan is designed for

Correct : D. bending moment, shear and torsion

58. Pick up the correct statement from the following:

Correct : D. all the above

59. 'Ware house pack' of cement means

Correct : C. pressure compaction of the bags on lower layers

60. High carbon content in the steel causes

Correct : B. increase in tensile strength but decrease in ductility

61. Particles of 0.002 mm size are that of

Correct : A. clay

62. Ultimate strength of cold drawn high steel wires

Correct : B. decreases with increase in diameter of bar

63. 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

Correct : A. low-heat portland cement

64. The dimensions of a 35 litre forma for measuring aggregates by volume, are:

Correct : C. length 27 cm, breadth 27 cm, height 48 cm

65. Ratio of permissible stress in direct compression and bending compression is

Correct : A. less than 1

66. Concrete containing

Correct : D. all the above

67. The lower water cement ratio in concrete, introduces

Correct : D. all the above

68. In T-shaped R C. retaining walls, the main reinforcement in the stem is provided on

Correct : C. the inner face in one direction

69. The aggregate containing moisture in pores and having its surface dry, is known as

Correct : D. saturated surface dry aggregate

70. Pick up the correct statement from the following:

Correct : D. all the above

71. According to ISI recommendations, the maximum depth of stress block for balanced section of a beam of effective depth d is

Correct : A. 0.43 d

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

Correct : A. lime : silica : alumina : iron oxide : 63 : 22 : 6 : 3

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

Correct : D. more water and coarse aggregates

74. Pick up the correct statement from the following:

Correct : D. all the above

75. Pick up the correct statement from the following:

Correct : D. all the above

76. If the effective plan area of a warehouse is 54 sq. m, and maximum height of piles permitted is 270 cm, the number of cement bags to be stored, is

Correct : D. 2700 bags

77. The property of fresh concrete, in which the water in the mix tends to rise to the surface while placing and compacting, is called

Correct : B. bleeding

78. Workability of concrete for a given water content is good if the aggregates, are

Correct : A. rounded aggregate

79. For preparing ordinary concrete, the quantity of water used, is

Correct : C. 5% by weight of aggregates plus 30% of weight of cement

80. Finer grinding of cement

Correct : A. affects only the early development of strength

81. The light weight aggregates are obtained from

Correct : D. volcanic source

82. The aggregate impact value of the aggregate used in

Correct : D. all the above

83. For walls, columns and vertical faces of all structural members, the form work is generally removed after

Correct : A. 24 to 48 hours

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

Correct : D. alkalis

85. For given workability the grading requiring the least amount of water is one that gives

Correct : A. greatest surface area for the given cement and aggregates

86. Minimum pitch of transverse reinforcement in a column is

Correct : D. lesser of the above three values

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

Correct : D. all the above

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

Correct : D. 75 mm

89. Workability of concrete mix with low water cement ratio is determined by

Correct : C. compaction factor test

90. The effect of creep on modular ratio is

Correct : B. to increase it

91. The type of aggregates not suitable for high strength concrete and for pavements subjected to tension, is

Correct : A. rounded aggregate

92. The maximum percentage of chemical ingredient of cement is that of

Correct : D. lime

93. The commercial name of white and coloured cement in India, is

Correct : D. all the above

94. An excess of flaky particles in concrete aggregates

Correct : D. all the above

95. Increase in the moisture content in concrete

Correct : A. reduces the strength

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

Correct : D. below 200 kg/cm2

97. Select the incorrect statement

Correct : D. none of the above

98. Permissible compressive strength of M 150 concrete grade is

Correct : C. 200 kg/cm2

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

Correct : D. siliceous, argillaceous and calcareous materials

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

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