Concrete Technology and Design 1000+ MCQ with answer for RBI Grade B officer

1. 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

2. The main reason for providing number of reinforcing bars at a support in a simply supported beam is to resist in that zone
A. Compressive stress
B. Shear stress
C. Bond stress
D. Tensile stress
Answer : C

3. The final operation of finishing floors, is known as
A. Screeding
B. Floating
C. Trowelling
D. Finishing
Answer : C

4. Permissible compressive strength of M 200 concrete grade is
A. 100 kg/cm2
B. 150 kg/cm2
C. 200 kg/cm2
D. 250 kg/cm2
Answer : C

5. 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
A. 1500 bags
B. 2000 bags
C. 2500 bags
D. 3000 bags
Answer : D

6. Joints in concrete structures, are provided
A. To reduce the tensile stresses likely to be developed due to evaporation of water
B. To minimise the change in the dimensions of the slab
C. To minimise the necessary cracking
D. All the above
Answer : D

7. The aggregate containing moisture in pores and having its surface dry, is known as
A. Moist aggregates
B. Very dry aggregates
C. Dry aggregates
D. Saturated surface dry aggregate
Answer : D

8. Workability of concrete mix with low water cement ratio is determined by
A. Tensile strength test
B. Slump test
C. Compaction factor test
D. Flexural strength test
Answer : C

9. Pick up the correct statement from the following:
A. The quality of water governs the strength of concrete
B. 10% excess of water reduces the strength of concrete by 15%
C. 30% excess of water reduces the strength of concrete by 50%
D. All the above
Answer : D

10. Due to circumferential action of the spiral in a spirally reinforced column
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
Answer : D

11. 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 mm to 50 mm
D. 50 mm to 60 mm
Answer : C

12. Concrete is unsuitable for compaction by a vibrator if it is
A. Dry
B. Earth moist
C. Semi-plastic
D. Plastic
Answer : D

13. In a ring beam subjected to uniformly distributed load (i) Shear force at mid span is zero (ii) Shear force at mid span is maximum (iii) Torsion at mid span is zero (iv) Torsion at mid span is maximum The correct answer is
A. (i) and (iii)
B. (i) and (iv)
C. (ii) and (iii)
D. (ii) and (iv)
Answer : A

14. If a beam fails in bond, then its bond strength can be increased most economically by
A. Increasing the depth of beam
B. Using thinner bars but more in number
C. Using thicker bars but less in number
D. Providing vertical stirrups
Answer : B

15. Minimum thickness of load bearing RCC wall should be
A. 50 mm
B. 100 mm
C. 150 mm
D. 200 mm
Answer : B

16. In working stress design, permissible bond stress in the case of deformed bars is more than that in plain bars by
A. 10 %
B. 20 %
C. 30 %
D. 40 %
Answer : D

17. 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

18. Pick up the correct statement from the following:
A. Insufficient quantity of water makes the concrete mix harsh
B. Insufficient quantity of water makes the concrete unworkable
C. Excess quantity of water makes the concrete segregated
D. All the above
Answer : D

19. In counterfort retaining walls, the main reinforcement in the stem at support is
A. Not provided
B. Provided only on inner face
C. Provided only on front face
D. Provided both on inner and front faces
Answer : B

20. The process of hardening the concrete by keeping its surface moist is known
A. Placing
B. Wetting
C. Curing
D. Compacting
Answer : C

21. Critical section for shear in case of flat slabs is at a distance of
A. Effective depth of slab from periphery of column/drop panel
B. d/2 from periphery of column/capital/ drop panel
C. At the drop panel of slab
D. At the periphery of column
Answer : B

22. Cement used for normal concrete construction, is obtained by burning a mixture of
A. Siliceous and argillaceous materials
B. Argillaceous and calcareous materials
C. Siliceous and calcareous materials
D. Siliceous, argillaceous and calcareous materials
Answer : D

23. Pick up the correct statement from the following:
A. Segregation is necessary for a workable concrete
B. Consistency does not affect the workability of concrete
C. If the concrete mix is dry, the slump is maximum
D. None of these
Answer : D

24. Which of the following losses of pre-stress occurs only in pretensioning and not in post-tensioning?
A. Elastic shortening of concrete
B. Shrinkage of concrete
C. Creep of concrete
D. Loss due to friction
Answer : A

25. The main reinforcement in the toe of a T-shaped R C. retaining wall is provided on
(i) Top face parallel to the wall
(ii) Top face perpendicular to the wall
(iii) Bottom face parallel to the wall
(iv) Bottom face perpendicular to the wall The correct answer is
A. Only (ii) is correct
B. (i) and (ii) are correct
C. (iii) and (iv) are correct
D. Only (iv) is correct
Answer : D

26. The approximate value of the ratio between direct tensile strength and flexural strength is
A. 0.33
B. 0.5
C. 0.75
D. 1.0
Answer : B

27. The type of aggregates not suitable for high strength concrete and for pavements subjected to tension, is
A. Rounded aggregate
B. Irregular aggregate
C. Angular aggregate
D. Flaky aggregate
Answer : A

28. Pick up the correct statement from the following:
A. The maximum size of a coarse aggregate, is 75 mm and minimum 4.75 mm
B. The maximum size of the fine aggregate, is 4.75 mm and minimum 0.075 mm
C. The material having particles of size varying from 0.06 mm to 0.002 mm, is known as silt
D. All the above
Answer : D

29. Pick up the correct statement from the following:
A. Higher workability indicates unexpected increase in the moisture content
B. Higher workability indicates deficiency of sand
C. If the concrete mix is dry, the slump is zero
D. All the above
Answer : D

30. Water cement ratio is generally expressed in volume of water required per
A. 10 kg
B. 20 kg
C. 30 kg
D. 50 kg
Answer : D

31. While designing an air entrained concrete
A. Water cement ratio is reduced
B. Proportion of aggregates is reduced
C. An allowance for the entrained air is made
D. All the above
Answer : D

32. For walls, columns and vertical faces of all structural members, the form work is generally removed after
A. 24 to 48 hours
B. 3 days
C. 7 days
D. 14 days
Answer : A

33. Pick up the correct statement from the following:
A. The free water is the amount of water added while mixing and the amount of water held on the surface of the aggregates prior to mixing
B. The total water is the free water and the amount actually absorbed by the aggregates
C. Neither (a) nor (b)
D. Both (a) and (b)
Answer : D

34. For a simply supported beam of span 15 m, the minimum effective depth to satisfy the vertical deflection limits should be
A. 600 mm
B. 750 mm
C. 900 mm
D. More than 1 m
Answer : B

35. Workability of concrete is directly proportional to
A. Aggregate cement ratio
B. Time of transit
C. Grading of the aggregate
D. All of above
Answer : C

36. The maximum percentage of chemical ingredient of cement is that of
A. Magnesium oxide
B. Iron oxide
C. Silica
D. Lime
Answer : D

37. The property of the ingredients to separate from each other while placing the concrete is called
A. Segregation
B. Compaction
C. Shrinkage
D. Bulking
Answer : A

38. The type of aggregates of same nominal size, which contain less voids when compacted, are
A. Rounded spherical
B. Irregular
C. Flaky
D. None of these
Answer : A

39. A higher modular ratio shows
A. Higher compressive strength of concrete
B. Lower compressive strength of concrete
C. Higher tensile strength of steel
D. Lower tensile strength of steel
Answer : B

40. For road pavements, the cement generally used, is
A. Ordinary Portland cement
B. Rapid hardening cement
C. Low heat cement
D. Blast furnace slag cement
Answer : B

41. The slab is designed as one way if the ratio of long span to short span is
A. Less than 1
B. Between 1 and 1.5
C. Between 1.5 and 2
D. Greater than 2
Answer : D

42. The strength and quality of concrete, depend upon:
A. Grading of aggregates
B. Surface area of aggregates
C. Shape of aggregates
D. All the above
Answer : D

43. On a grading curve, the gap grading is represented by
A. A horizontal line
B. A vertical line
C. N.W. inclined line
D. N.E. inclined line
Answer : A

44. Examine the following statements: (i) Factor of safety for steel should be based on its yield stress, (ii) Factor of safety for steel should be based on its ultimate stress, (iii) Factor of safety for concrete should be based on its yield stress, (iv) Factor of safety for concrete should be based on its ultimate stress. The correct statements are
A. (i) and (iii)
B. (i) and (iv)
C. (ii) and (iii)
D. (ii) and (iv)
Answer : B

45. The lower water cement ratio in concrete, introduces
A. Smaller creep and shrinkage
B. Greater density and smaller permeability
C. Improved frost resistance
D. All the above
Answer : D

46. The load factors for live load and dead load are taken respectively as
A. 1.5 and 2.2
B. 2.2 and 1.5
C. 1.5 and 1.5
D. 2.2 and 2.2
Answer : B

47. Bulking of sand is maximum if moisture content is about
A. 2 %
B. 4 %
C. 6 %
D. 10 %
Answer : B

48. The relation between modulus of rupture f_cr, splitting strength f_cs and direct tensile strength f_cl is given by
A. f_cr - f_cs = f_cl
B. f_cr > f_cs > f_cl
C. f_cr < f_cs < f_cl
D. f_cs > f_cr > f_cl
Answer : B

49. The mixture of different ingredients of cement, is burnt at
A. 1000°C
B. 1200°C
C. 1400°C
D. 1600°C
Answer : C

50. 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