1000+ Concrete Technology and Design Multiple Choice Question Answer [Solved]

1. Pick up the incorrect statement from the following. For performing compressive strength test of cement
A. Cement and standard sand mortar are used in the ratio of 1 : 3
B. Water is added at the rate of (P/4) + 3.0 percentage of water where P is the percentage of water for standard consistency
C. A cube mould of 10 cm × 10 cm × 10 cm is used
D. The prepared moulds are kept in a atmosphere of 50% relative humidity
Answer : A

2. 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

3. Grading of sand causes great variation in
A. Workability of concrete
B. Strength of concrete
C. Durability of concrete
D. All the above
Answer : D

4. Which of the following R.C. retaining walls is suitable for heights beyond 6 m?
A. L-shaped wall
B. T-shaped wall
C. Counterfort type
D. All of the above
Answer : C

5. Diagonal tension in a beam
A. Is maximum at neutral axis
B. Decreases below the neutral axis and increases above the neutral axis
C. Increases below the neutral axis and decreases above the neutral axis
D. Remains same
Answer : C

6. 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

7. 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

8. 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

9. 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

10. If fineness modulus of sand is 2.5, it is graded as
A. Very fine sand
B. Fine sand
C. Medium sand
D. Coarse sand
Answer : B

11. Pick up the correct statement from the following:
A. Cement should be mixed for at least one minute
B. 10% of water is placed in the rotating drum before adding dry material
C. 10% of water is added after placing the other ingredients in the drum
D. All the above
Answer : D

12. Pick up the correct statement from the following:
A. Continuous grading is not necessary for obtaining a minimum of air voids
B. The omission of a certain size of aggregate is shown by a straight horizontal line on the grading curve
C. The omission of a certain size of aggregate in concrete increases the workability but also increases the liability to segregation
D. All the above
Answer : D

13. For construction of structures in sea water, the cement generally preferred to, is
A. Portland-pozzolana cement
B. Quick setting cement
C. Low heat Portland cement
D. Rapid hardening cement
Answer : A

14. Pick up the incorrect statement from the following. While performing preliminary test on concrete
A. Proportions of the material and water should be the same as to be used at the work site
B. Cement should be mixed by hand in order to maintain uniformity
C. Concrete mix should be stored in air-tight containers
D. Concrete ingredients should be kept at a temperature of 37° ± 2°C
Answer : D

15. Ratio of permissible stress in direct compression and bending compression is
A. Less than 1
B. Between 1 and 1.5
C. Between 1.5 and 2.0
D. Greater than 2
Answer : A

16. A construction joint is provided where
A. Bending moment is small
B. Shear force is small
C. The member is supported by other member
D. All the above
Answer : D

17. Pozzolanic properties exist in
A. Shales
B. Fly ash
C. Pumicite
D. All the above
Answer : D

18. In a counterfort retaining wall, the main reinforcement is provided on the (i) Bottom face in front counterfort (ii) Inclined face in front counterfort (iii) Bottom face in back counterfort (iv) Inclined face in back counterfort The correct answer is
A. (i) and (ii),
B. (ii) and (iii)
C. (i) and (iv)
D. (iii) and (iv)
Answer : C

19. I.S. Sieve Nos. 10 mm and 4.75 mm are generally used for grading of
A. Coarse aggregates
B. Fine aggregates
C. Neither (a) nor (b)
D. Both (a) and (b)
Answer : D

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. 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

22. The maximum thickness of concrete floor of a cement warehouse, is
A. 10 cm
B. 15 cm
C. 20 cm
D. 25 cm
Answer : D

23. For the design of retaining walls, the minimum factor of safety against overturning is taken as
A. 1.5
B. 2.0
C. 2.5
D. 3.0
Answer : B

24. 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

25. Air entrainment in the concrete increases
A. Workability
B. Strength
C. The effects of temperature variations
D. The unit weight
Answer : A

26. Pick up the correct statement from the following:
A. Construction joints in columns are provided a few cm below the junction of beam
B. Construction joints in columns are provided at the bottom hunching
C. Construction joints in beams and slabs are provided within middle third
D. All the above
Answer : D

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

28. 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

29. In counterfort type retaining walls (i) The vertical slab is designed as a continuous slab (ii) The heel slab is designed as a continuous slab (iii) The vertical slab is designed as a cantilever (iv) The heel slab is designed as a cantilever The correct answer is
A. (i) and (ii)
B. (i)and(iv)
C. (ii) and (iii)
D. (iii) and (iv)
Answer : A

30. Tricalcium aluminate (C₃A)
A. Reacts fast with water
B. Generates less heat of hydration
C. Causes initial setting and early strength of cement
D. Does not contribute to develop ultimate strength
Answer : B

31. 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

32. The rock which is not calcareous, is:
A. Lime stone
B. Chalk
C. Laterite
D. None of these
Answer : D

33. The minimum cover to the ties or spirals should not be less than
A. 15 mm
B. 20 mm
C. 25 mm
D. 50 mm
Answer : C

34. Pick up the correct statement from the following:
A. High percentage of C₃S and low percentage of C₂S cause rapid hardening
B. High percentage of C₃S and low percentage of C₂S make the cement less resistive to chemical attack
C. Low percentage of C₃S and high percentage of C₂S contribute to slow hardening
D. All the above
Answer : D

35. For concreting of heavily reinforced sections without vibration, the workability of concrete expressed as compacting factor should be
A. 0.75 - 0.80
B. 0.80 - 0.85
C. 0.85 - 0.92
D. Above 0.92
Answer : D

36. Concrete mainly consists of
A. Cement
B. Aggregates
C. Water
D. All the above
Answer : D

37. The following proportion of the ingredients of concrete mix, is not in conformation to arbitrary method of proportioning
A. 1 : 1 : 2
B. 1 : 2 : 4
C. 1 : 3 : 6
D. 1 : 4 : 10
Answer : D

38. Saw dust can be rendered chemically inert by boiling it in water containing
A. Ferrous sulphate
B. Potassium chloride
C. Ammonia
D. Nitric acid
Answer : A

39. For concreting tunnel linings, transportation of concrete is done by
A. Pans
B. Wheel borrows
C. Containers
D. Pumps
Answer : D

40. The dimensions of a 35 litre forma for measuring aggregates by volume, are:
A. Length 30 cm, breadth 25 cm, height 30 cm
B. Length 39 cm, breadth 25 cm, height 32 cm
C. Length 27 cm, breadth 27 cm, height 48 cm
D. Length 220 cm, breadth 25 cm, height 40 cm
Answer : C

41. Pick up the correct statement from the following:
A. Calcium chloride acts as a retarder
B. Calcium chloride acts as an accelerator
C. Gypsum (calcium sulphate) acts as a retarder
D. Both (b) and (c)
Answer : D

42. 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

43. 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

44. 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

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

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

47. The most useless aggregate is one whose surface texture is
A. Smooth
B. Granular
C. Glassy
D. Honey combed and porous
Answer : C

48. For the construction of R.C.C. slabs, columns, beams, walls, etc. the grade of concrete mix used, is
A. 1 : 3 : 6
B. 1 : 1 ½ : 3
C. 1 : 2 : 4
D. 1 : 1 : 2
Answer : C

49. Half of the main steel in a simply supported slab is bent up near the support at a distance of x from the center of slab bearing where x is equal to (Where l is the span)
A. l/3
B. l/5
C. l/7
D. l/10
Answer : C

50. To determine the modulus of rupture, the size of test specimen used is
A. 150 × 150 × 500 mm
B. 100 × 100 × 700 mm
C. 150 × 150 × 700 mm
D. 100 × 100 × 500 mm
Answer : C