design of concrete structures Mcqs
1. Bulking of sand is maximum if moisture content is about____________?
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A. 10%

B. 4%

C. 2%

D. 6%

2. Which of the following R.C. retaining walls is suitable for heights beyond 6m ?
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A. counterfort type

B. all of the above

C. T-shaped wall

D. L-shaped wall

3. Strength of concrete increases with________________?
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A. decrease in curing time

B. increase in fineness of cement

C. decrease in size of aggregate

D. increase in water-cement ratio

4. Diagonal tension in a beam______________?
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A. decreases below the neutral axis and increases above the neutral axis

B. is maximum at neutral axis

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

D. remains same

5. Which of the following statements is incorrect ?
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A. Spacing of longitudinal bars measured along the periphery of column should not exceed 300 mm

B. Minimum cross sectional area of longitudinal reinforcement in a column is 0.8%

C. The number of longitudinal bars provided in a circular column should not be less than four

D. Reinforcing bars in a column should not be less than 12 mm in diameter

6. Due to circumferential action of the spiral in a spirally reinforced column________________?
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A. capacity of column is decreased

B. ductility of column reduces

C. capacity of column is decreased but ductility of column increases

D. both the capacity of column and ductility of column increase
7. The property of fresh concrete, in which the water in the mix tends to rise to the surface while placing and compacting, is called________________?
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A. bleeding

B. segregation

C. creep

D. bulking

8. The compressive strength of 100 mm cube as compared to 150 mm cube is always_______________?
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A. more

B. none of the above

C. less

D. equal

9. Maximum distance between expansion joints in structures as per IS : 456 1978 is________________?
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A. 60 m

B. 20 m

C. 30 m

D. 45 m
10. The slab is designed as one way if the ratio of long span to short span is_____________?
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A. less than 1

B. between 1 and 1.5

C. greater than 2

D. between 1.5 and 2

11. According to IS : 456-1978, the cblumn or the strut is the member whose effective length is greater than________________?
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A. 4 times the least lateral dimension

B. the least lateral dimension

C. 2 times the least lateral dimension

D. 3 times the least lateral dimension
12. Finer grinding of cement______________?
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A. affects only the early development of strength

B. affects only the ultimate strength

C. both (A. and (B.

D. does not affect the strength

13. In a pile of length /, the points of suspension from ends for lifting it are located at______________?
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A. 0.207 1

B. 0.25 /

C. 0.333 /

D. 0.293 /

14. The minimum diameter of longitudinal bars in a column is________________?
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A. 6 mm

B. 12 mm

C. 8 mm

D. 16 mm

15. In reinforced concrete footing on soil, the minimum thickness at edge should not be less than______________?
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A. 150 mm

B. 250 mm

C. 200 mm

D. 100 mm

16. When shear stress exceeds the permissible limit in a slab, then it is reduced by____________?
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A. using high strength steel

B. increasing the depth

C. using thinner bars but more in number

D. providing shear reinforcement

17. Modulus of elasticity of steel as per IS : 456-1978 shall be taken as______________?
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A. 20 kN/cm2

B. 2xl06N/cm2

C. 200kN/mm2

D. 200 kN/cm2

18. Workability of concrete is inversely proportional to______________?
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A. time of transit

B. vater-cement ratio

C. the air in the mix

D. size of aggregate

19. For a longitudinal reinforcing bar in a column, the minimum cover shall neither be less than the diameter of bar nor less than_______________?
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A. 40 mm

B. 15 mm

C. 25 mm

D. 30 mm

20. The main reinforcement in the heel of a T-shaped R.C. retaining wall is provided on______________?
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A. top face perpendicular to wall

B. bottom face perpendicular to wall

C. both top and bottom faces perpendicular to wall

D. none of the above

21. A continuous beam is deemed to be a deep beam when the ratio of effective span to overall depth (1/D. is less than__________________?
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A. 2.5

B. 3

C. 1.5

D. 2

22. The percentage of voids in cement is approximately_______________?
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A. 60%

B. 40%

C. 25%

D. 80%

23. The fineness modulus of fine aggregate is in the range of______________?
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A. 2.0 to 3.5

B. 3.5 to 5.0

C. 6.0 to 8.5

D. 5.0 to 7.0

24. Ratio of permissible stress in direct compression and bending compression is______________?
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A. between 1.5 and 2.0

B. less than 1

C. greater than 2

D. between 1 and 1.5

25. The main reason for providing number of reinforcing bars at a support in a simply supported beam is to resist in that zone_________________?
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A. bond stress

B. tensile stress

C. shear stress

D. compressive stress

26. According to IS : 456-1978, the fiexural strength of concrete is________________?
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A. inversely proportional to compressive strength

B. inversely proportional to square root of compressive strength

C. directly proportional to square root of compressive strength

D. directly proportional to compressive strength

27. A higher modular ratio shows____________?
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A. higher tensile strength of steel

B. lower compressive strength of concrete

C. lower tensile strength of steel

D. higher compressive strength of con-crete

28. The percentage of reinforcement in case of slabs, when high strength deformed bars are used is not less than________________?
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A. 0.3

B. 1

C. 0.15

D. 0.12
29. Maximum percentage reinforcement in case of slabs is limited to___________________?
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A. 8

B. 2

C. 4

D. 6

30. In order to obtain the best workability of concrete, the preferred shape of aggregate is_______________?
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A. rounded

B. all of the above

C. elongated

D. angular

31. The property of the ingredients to separate from each other while placing the concrete is called____________?
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A. shrinkage

B. segregation

C. bulking

D. compaction

32. Minimum thickness of load bearing RCC wall should be_____________?
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A. 100 mm

B. 50 mm

C. 150 mm

D. 200 mm

33. The diameter of ties in a column should be_______________?
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A. more than or equal to 5 mm

B. more than or equal to one fourth of diameter of main bar

C. more than 5 mm but less than one-fourth of diameter of main bar

D. more than 5 mm and also more than one-fourth of diameter of main bar
34. If the depth of actual neutral axis in a beam is more than the depth of critical neutral axis, then the beam is called________________?
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A. over-reinforced beam

B. balanced beam

C. none of the above

D. under-reinforced beam

35. Air entrainment in the concrete increases________________?
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A. strength

B. the unit weight

C. workability

D. the effects of temperature variations

36. In working stress design, permissible bond stress in the case of deformed bars is more than that in plain bars by_______________?
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A. 10%

B. 40%

C. 30%

D. 20%

37. To determine the modulus of rupture, the size of test specimen used is_______________?
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A. 100 x100 x700 mm

B. 150 x150 x700 mm

C. 100 x100 x500 mm

D. 150 x150 x500 mm

38. 1% of voids in a concrete mix would reduce its strength by about______________?
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A. 20%

B. 5%

C. 15%

D. 10%

39. For a reinforced concrete section, the shape of shear stress diagram is_______________?
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A. wholly rectangular

B. parabolic above neutral axis and rectangular below neutral axis

C. wholly parabolic

D. rectangular above neutral axis and parabolic below neutral axis

40. As compared to ordinary portland cement, use of pozzuolanic cement_______________?
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A. increases shrinkage

B. reduces workability

C. increases strength

D. increases bleeding

41. The limits of percentage p of the longitudinal reinforce-ment in a column is given by_____________?
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A. 0.15% to 2%

B. 0.8% to 4%

C. 0.8% to 8%

D. 0.8% to 6%
42. 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 Rankines theory_______________?
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A. is always greater than 1

B. can be less than 1

C. is always less than 1

D. can be more than 1

43. For walls, columns and vertical faces of all structural members, the form work is generally removed after______________?
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A. 24 to 48 hours

B. 7 days

C. 14 days

D. 3 days

44. For concreting of heavily reinforced sections without vibration, the workability of concrete expressed as compacting factor should be________________?
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A. above 0.92

B. 0.75-0.80

C. 0.80-0.85

D. 0.85 0.92

45. The average permissible stress in bond for plain bars in tension is_______________?
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A. increased by 25% for bars in compression

B. decreased by 10% for bars in compression

C. decreased by 25% for bars in compression

D. increased by 10% for bars in compression

46. Admixtures which cause early setting, and hardening of concrete are called_______________?
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A. retarders

B. accelerators

C. workability admixtures

D. air entraining agents

47. For a simply supported beam of span 15m, the minimum effective depth to satisfy the vertical deflection limits should be________________?
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A. 900 mm

B. 750 mm

C. more than 1 m

D. 600 mm

48. Increase in the moisture content in concrete_________________?
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A. all of the above

B. does not change the strength

C. reduces the strength

D. increases the strength

49. As compared to ordinary portland cement, high alumina cement has______________?
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A. higher initial setting time but lower final setting time

B. lower initial and final setting times

C. lower initial setting time but higher final setting time

D. higher initial and final setting times

50. To minimise the effect of differential settlement, the area of a footing should be designed for______________?
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A. live load + fraction of dead load

B. dead load only

C. dead load + live load

D. dead load + fraction of live load