Concrete Technology and Design 1000+ MCQ with answer for NEET PG

1. The impurity of mixing water which affects the setting time and strength of concrete, is
A. Sodium sulphates
B. Sodium chlorides
C. Sodium carbonates and bicarbonates
D. Calcium bicarbonates
Answer : C

2. The percentage of reinforcement in case of slabs, when high strength deformed bars are used is not less than
A. 0.15
B. 0.12
C. 0.30
D. 1.00
Answer : B

3. Particles of 0.002 mm size are that of
A. Clay
B. Sand
C. Gravel
D. None of these
Answer : A

4. Most common method of pre-stressing used for factory production is
A. Long line method
B. Freyssinet system
C. Magnel-Blaton system
D. Lee-Macall system
Answer : A

5. The grade of concrete not recommended by I.S. : 456, is
A. M 100
B. M 200
C. M 300
D. M 500
Answer : D

6. Pick up the correct statement from the following:
A. Construction joints are necessarily planned for their locations
B. Expansion joints are provided to accommodate thermal expansion
C. Construction joints are provided to control shrinkage cracks
D. All the above
Answer : D

7. Pick up the incorrect statement from the following:
A. In properly graded aggregates, bulk density is more
B. In single size aggregates, bulk density is least
C. In single size aggregates, bulk density is maximum
D. None of these
Answer : C

8. 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

9. For the construction of the retaining structures, the type of concrete mix to be used, is
A. 1 : 3 : 6
B. 1 : 2 : 4
C. 1 : 1 ½ : 3
D. 1 : 4 : 8
Answer : C

10. The minimum cover in a slab should neither be less than the diameter of bar nor less than
A. 10 mm
B. 15 mm
C. 25 mm
D. 13 mm
Answer : B

11. If 50 kg of fine aggregates and 100 kg of coarse aggregates are mixed in a concrete whose water cement ratio is 0.6, the weight of water required for harsh mix, is
A. 8 kg
B. 10 kg
C. 12 kg
D. 14 kg
Answer : C

12. The commonly used material in the manufacture of cement is
A. Sand stone
B. Slate
C. Lime stone
D. Graphite
Answer : C

13. Pick up the correct statement from the following:
A. Sand stones may be divided into calcareous, siliceous and ferruginous sand stones
B. Concrete using sand stones, cracks due to excessive shrinkage
C. Broken bricks produce a concrete having good fire resisting qualities
D. All the above
Answer : D

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

15. According to IS: 4561978, the column or the strut is the member whose effective length is greater than
A. The least lateral dimension
B. 2 times the least lateral dimension
C. 3 times the least lateral dimension
D. 4 times the least lateral dimension
Answer : C

16. According to I.S. : 456, the number of grades of concrete mixes, is
A. 3
B. 4
C. 5
D. 7
Answer : D

17. 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

18. Efflorescence in cement is caused due to an excess of
A. Alumina
B. Iron oxide
C. Silica
D. Alkalis
Answer : D

19. The load carrying capacity of a helically reinforced column as compared to that of a tied column is about
A. 5 % less
B. 10 % less
C. 5 % more
D. 10 % more
Answer : C

20. Transport of concrete by pumps, is done for a distance of
A. 100 m
B. 200 m
C. 300 m
D. 400 m
Answer : D

21. Pick up the correct statement from the following:
A. Water cement paste hardens due to hydration
B. During hardening cement binds the aggregates together
C. Cement provides strength, durability and water tightness to the concrete
D. All the above
Answer : D

22. 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

23. 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

24. The maximum amount of dust which may be permitted in aggregates is
A. 5% of the total aggregates for low workability with a coarse grading
B. 10% of the total aggregates for low workability with a fine grading
C. 20% of the total aggregates for a mix having high workability with fine grading
D. All the above
Answer : D

25. The cement becomes useless if its absorbed moisture content exceeds
A. 1 %
B. 2 %
C. 3 %
D. 5 %
Answer : D

26. Approximate value of shrinkage strain in concrete, is
A. 0.003
B. 0.0003
C. 0.00003
D. 0.03
Answer : B

27. To minimise the effect of differential settlement, the area of a footing should be designed for
A. Dead load only
B. Dead load + live load
C. Dead load + fraction of live load
D. Live load + fraction of dead load
Answer : C

28. If P, Y and Z are the weights of cement, fine aggregates and coarse aggregates respectively and W/C is the water cement ratio, the minimum quantity of water to be added to first batch, is obtained by the equation
A. 0.1P + 0.3Y + 0.1Z = W/C × P
B. 0.3P + 0.1Y + 0.01Z = W/C × P
C. 0.4P + 0.2Y + 0.01Z = W/C × P
D. 0.5P + 0.3Y + 0.01Z = W/C × P
Answer : B

29. Shrinkage in concrete can be reduced by using
A. Low water cement ratio
B. Less cement in the concrete
C. Proper concrete mix
D. All the above
Answer : D

30. The effect of creep on modular ratio is
A. To decrease it
B. To increase it
C. Either to decrease or to increase it
D. To keep it unchanged
Answer : B

31. Slump test of concrete is a measure of its
A. Consistency
B. Compressive strength
C. Tensile strength
D. Impact value
Answer : A

32. Sinking of an intermediate support of a continuous beam (i) Reduces the negative moment at support (ii) Increases the negative moment at support (iii) Reduces the positive moment at center of span (iv) Increases the positive moment at center of span The correct answer is
A. (i) and (iii)
B. (i) and (iv)
C. (ii) and (iii)
D. (ii) and (iv)
Answer : B

33. The light weight aggregates are obtained from
A. Sedimentary rocks
B. Metamorphic rocks
C. Igneous rocks
D. Volcanic source
Answer : D

34. 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

35. Addition of pozzolana to cement
A. Decreases workability
B. Increases strength
C. Increases heat of hydration
D. None of these
Answer : D

36. The diameter of ties in a column should be
A. More than or equal to one fourth of diameter of main bar
B. More than or equal to 5 mm
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
Answer : D

37. M10 grade of concrete approximates
A. 1 : 3 : 6 mix
B. 1 : 1 : 2 mix
C. 1 : 2 : 4 mix
D. 1 : 1.5 : 3 mix
Answer : A

38. 1% of voids in a concrete mix would reduce its strength by about
A. 5 %
B. 10 %
C. 15 %
D. 20 %
Answer : A

39. 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

40. The limits of percentage p of the longitudinal reinforcement in a column is given by
A. 0.15% to 2%
B. 0.8% to 4%
C. 0.8% to 6%
D. 0.8% to 8%
Answer : C

41. To ensure constant moisture content in aggregates
A. Area of each aggregate pile should be large
B. Height of each aggregate pile should not exceed 1.50 m
C. Aggregate pile should be left for 24 hours before aggregates are used
D. All the above
Answer : D

42. Which of the following statements is incorrect?
A. Minimum cross sectional area of longitudinal reinforcement in a column is 0.8%
B. Spacing of longitudinal bars measured along the periphery of column should not exceed 300 mm
C. Reinforcing bars in a column should not be less than 12 mm in diameter
D. The number of longitudinal bars provided in a circular column should not be less than four
Answer : D

43. The maximum value of hoop compression in a dome is given by
A. wR / 4d
B. wR/2d
C. wR/d
D. 2wR/d Where, w = load per unit area of surface of dome R = radius of curvature d = thickness of dome
Answer : B

44. In a pile of length l, the points of suspension from ends for lifting it are located at
A. 0.207 l
B. 0.25 l
C. 0.293 l
D. 0.333 l
Answer : A

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

46. In the design of a front counterfort in a counterfort retaining wall, the main reinforcement is provided on (i) Bottom face near counterfort (ii) Top face near counterfort (iii) Bottom face near centre of span (iv) Top face near centre of span The correct answer is
A. Only (i)
B. Only (ii)
C. Both (i) and (iv)
D. Both (ii) and (iii)
Answer : C

47. The most commonly used admixture which prolongs the setting and hardening time is
A. Gypsum
B. Calcium chloride
C. Sodium silicate
D. All of the above
Answer : A

48. 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

49. The size of fine aggregates does not exceed
A. 2.75 mm
B. 3.00 mm
C. 3.75 mm
D. 4.75 mm
Answer : D

50. The depth of footing for an isolated column is governed by (i) Maximum bending moment (ii) Shear force (iii) Punching shear The correct answer is
A. Only (i)
B. (i) and (ii)
C. (i) and (iii)
D. All (i), (ii) and (iii)
Answer : D