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

1. An ordinary Portland cement when tested for its fineness, should not leave any residue on I.S. sieve No. 9, more than
A. 5 %
B. 10 %
C. 15 %
D. 20 %
Answer : B

2. Maximum percentage reinforcement in case of slabs is limited to
A. 2
B. 4
C. 6
D. 8
Answer : B

3. 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

4. Workability improved by adding
A. Fly ash
B. Hydrated lime
C. Calcium chloride
D. All the above
Answer : D

5. For an ordinary Portland cement
A. Residual does not exceed 10% when sieved through IS Sieve No. 9
B. Soundness varies from 5 to 10 mm
C. Initial setting time is not less than 30 minutes
D. Compressive stress after 7 days, is not less than 175 kg/cm²
Answer : C

6. The grade of concrete M 150 means that compressive strength of a 15 cm cube after 28 days, is
A. 100 kg/cm2
B. 150 kg/cm2
C. 200 kg/cm2
D. 250 kg/cm2
Answer : B

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

8. According to IS: 4561978, the maximum reinforcement in a column is
A. 2 %
B. 4 %
C. 6 %
D. 8 %
Answer : C

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

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. According to the recommendations of IS : 456-1978, the expansion joints
A. Are provided where plane changes abruptly
B. Are provided to ensure minimum resistance
C. Do not carry reinforcement across them
D. All the above
Answer : D

12. The permissible diagonal tensile stress in reinforced brick work is
A. About 0.1 N/mm²
B. Zero
C. 0.3 N/mm² to 0.7 N/mm²
D. About 1.0 N/mm²
Answer : A

13. If X, Y and Z are the fineness modulli of coarse, fine and combined aggregates, the percentage (P) of fine aggregates to combined aggregates, is
A. P = [(Z - X)/(Z - Y)] × 100
B. P = [(X - Z)/(Z - Y)] × 100
C. P = [(X - Z)/(Z + Y)] × 100
D. P = [(Z + X)/(Z - Y)] × 100
Answer : B

14. Horizontal construction joints in concrete walls are generally provided at
A. Soffit level
B. Window sill level
C. Floor level
D. All the above
Answer : D

15. 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

16. For a continuous slab of 3 m × 3.5 m size, the minimum overall depth of slab to satisfy vertical deflection limits is
A. 50 mm
B. 75 mm
C. 100 mm
D. 120 mm
Answer : B

17. According to Whitney's theory, ultimate strain of concrete is assumed to be
A. 0.03 %
B. 0.1 %
C. 0.3 %
D. 3 %
Answer : C

18. An ideal ware house, is provided
A. Water proof masonry walls
B. Water proof roof
C. Few windows which remain generally closed
D. All the above
Answer : D

19. Gypsum is added for
A. Colour
B. Strength
C. Controlling setting time
D. None of these
Answer : C

20. 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

21. The effect of adding calcium chloride in concrete is (i) To increase shrinkage (ii) To decrease shrinkage (iii) To increase setting time (iv) To decrease setting time The correct answer is
A. (i) and (iii)
B. (i) and (iv)
C. (ii) and (iii)
D. (ii) and (iv)
Answer : B

22. In reinforced concrete footing on soil, the minimum thickness at edge should not be less than
A. 100 mm
B. 150 mm
C. 200 mm
D. 250 mm
Answer : B

23. 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

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

25. A continuous beam is deemed to be a deep beam when the ratio of effective span to overall depth (1/D) is less than
A. 1.5
B. 2.0
C. 2.5
D. 3.0
Answer : C

26. The preliminary test is repeated if the difference of compressive strength of three test specimens, exceeds
A. 5 kg/cm²
B. 8 kg/cm²
C. 10 kg/cm²
D. 15 kg/cm²
Answer : D

27. Vicat's apparatus is used for
A. Fineness test
B. Consistency test
C. Setting time test
D. Soundness test
Answer : B

28. Addition of pozzolana to cement causes
A. Reduction in permeability
B. Loss of heat of hydration
C. Reduction in bleeding
D. All the above
Answer : D

29. Permissible compressive strength of M 300 concrete grade is
A. 100 kg/cm²
B. 150 kg/cm²
C. 200 kg/cm²
D. 300 kg/cm²
Answer : D

30. The strength of concrete after one year as compared to 28 days strength is about
A. 10 to 15% more
B. 15 to 20% more
C. 20 to 25% more
D. 25 to 50% more
Answer : C

31. Bulking of sand is
A. Mixing of different sizes of sand particles
B. Mixing of lime with sand
C. Maximum water with sand
D. Swelling of sand when wetted
Answer : D

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

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

34. For a concrete mix 1:3:6 and water cement ratio 0.6 both by weight, the quantity of water required per bag, is
A. 10 kg
B. 12 kg
C. 14 kg
D. 16 kg
Answer : C

35. The percentage of the aggregate of F.M. 2.6 to be combined with coarse aggregate of F.M. 6.8 for obtaining the aggregates of F.M. 5.4, is
A. 30 %
B. 40 %
C. 50 %
D. 60 %
Answer : C

36. 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

37. Allowable shear strength of concrete, depends upon
A. Shear strength
B. Tensile strength
C. Compressive strength
D. None of these
Answer : A

38. How long will it take for the concrete to achieve 100% of its strength?
A. 7 days
B. 14 days
C. 21 days
D. 28 days
Answer : D

39. Pick up the correct statement from the following:
A. An increase in water content must be accompanied by an increase in cement content
B. Angular and rough aggregates reduce the workability of the concrete
C. The slump of the concrete mix decreases due to an increase in temperature
D. All the above
Answer : D

40. The compressive strength of 100 mm cube as compared to 150 mm cube is always
A. Less
B. More
C. Equal
D. None of the above
Answer : B

41. If the permissible stress in steel in tension is 140 N/mm², then the depth of neutral axis for a singly reinforced rectangular balanced section will be
A. 0.35 d
B. 0.40 d
C. 0.45 d
D. Dependent on grade of concrete also
Answer : B

42. 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

43. The compaction of concrete, improves
A. Density
B. Strength
C. Durability
D. All the above
Answer : D

44. 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

45. Separation of coarse aggregates from mortar during transportation, is known
A. Bleeding
B. Creeping
C. Segregation
D. Shrinkage
Answer : C

46. If aggregates completely pass through a sieve of size 75 mm and are retained on a sieve of size 60 mm, the particular aggregate will be flaky if its minimum dimension is less than
A. 20.5 mm
B. 30.5 mm
C. 40.5 mm
D. 50.5 mm
Answer : C

47. Sand generally contains salt if it is obtained from:
A. Nala beds
B. River beds
C. Sea beds
D. None of these
Answer : C

48. Hardening of cement occurs at
A. Rapid rate during the first few days and afterwards it continues to increase at a decreased rate
B. Slow rate during the first few days and afterwards it continues to increase at a rapid rate
C. Uniform rate throughout its age
D. None of these
Answer : D

49. The purpose of reinforcement in pre-stressed concrete is
A. To provide adequate bond stress
B. To resist tensile stresses
C. To impart initial compressive stress in concrete
D. All of the above
Answer : C

50. 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