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

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

2. The ratio of the diameter of reinforcing bars and the slab thickness is
A. 1/4
B. 1/5
C. 1/6
D. 1/8
Answer : D

3. 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

4. The produce impermeable concrete
A. Thorough mixing of concrete is required
B. Proper compaction of concrete is required
C. Proper curing of concrete is required
D. All the above
Answer : D

5. Too wet concrete may cause
A. Weakness of concrete
B. Excessive laitance
C. Segregation
D. All the above
Answer : D

6. The cement whose strength is a little lower than the ordinary cement during the first three months but attains afterwards the same strength, is known as
A. Low-heat Portland cement
B. Rapid hardening Portland cement
C. Portland blast slag cement
D. Portland pozzolana cement
Answer : A

7. 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

8. Pick up the correct statement from the following:
A. According to the petrological characteristics, concrete aggregates are classified as heavy weight, normal weight and light weight
B. According to the shape of the particles, concrete aggregates are classified as rounded irregular, angular and flaky
C. According to the surface texture of the particles, the concrete aggregates are classified as glassy, smooth, granular, rough, crystalline, honey combed and porous
D. All the above
Answer : D

9. If 1500 g of water is required to have a cement paste 1875 g of normal consistency, the percentage of water is,
A. 20 %
B. 25 %
C. 30 %
D. 35 %
Answer : B

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

11. Batching error means inaccuracy in the quantity of
A. Aggregates
B. Cement
C. Water
D. All the above
Answer : D

12. The shuttering of a hall measuring 4 m × 5 m, can be removed after
A. 5 days
B. 7 days
C. 10 days
D. 14 days
Answer : B

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

14. 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

15. Minimum grade of concrete to be used in reinforced concrete as per IS: 4561978 is
A. M 15
B. M 20
C. M 10
D. M 25
Answer : A

16. To hydrate 500kg of cement full water needed, is
A. 100 kg
B. 110 kg
C. 120 kg
D. 130 kg
Answer : D

17. An aggregate is known as cyclopean aggregate if its size is more than
A. 4.75 mm
B. 30 mm
C. 60 mm
D. 75 mm
Answer : D

18. In a spherical dome subjected to concentrated load at crown or uniformly distributed load, the meridional force is always
A. Zero
B. Tensile
C. Compressive
D. Tensile or compressive
Answer : C

19. 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

20. 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

21. In pre-stressed concrete
A. Forces of tension and compression change but lever arm remains unchanged
B. Forces of tension and compressions remain unchanged but lever arm changes with the moment
C. Both forces of tension and compression as well as lever arm change
D. Both forces of tension and compression as well as lever arm remain unchanged
Answer : B

22. M 150 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 : B

23. If the foundations of all the columns of a structure are designed on the total live and dead load basis, then
A. There will be no settlement of columns
B. There will be no differential settlement
C. The settlement of exterior columns will be more than interior columns
D. The settlement of interior columns will be more than exterior columns
Answer : C

24. A flaky aggregate is said to be elongated if its length is
A. Equal to the mean size
B. Twice the mean size
C. Thrice the mean size
D. Four times the mean size
Answer : B

25. 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

26. 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

27. 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

28. 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

29. Maximum distance between expansion joints in structures as per IS: 456 1978 is
A. 20 m
B. 30 m
C. 45 m
D. 60 m
Answer : C

30. 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

31. The fineness modulus of fine aggregate is in the range of
A. 2.0 to 3.5
B. 3.5 to 5.0
C. 5.0 to 7.0
D. 6.0 to 8.5
Answer : A

32. Vicat apparatus is used for
A. Fineness test
B. Consistency test
C. Test for setting time
D. Test for tensile strength
Answer : B

33. For a longitudinal reinforcing bar in a column, the minimum cover shall neither be less than the diameter of bar nor less than
A. 15 mm
B. 25 mm
C. 30 mm
D. 40 mm
Answer : D

34. The operation of removing humps and hollows of uniform concrete surface, is known as
A. Floating
B. Screeding
C. Trowelling
D. Finishing
Answer : B

35. If the storey height is equal to length of RCC wall, the percentage increase in strength is
A. 0
B. 10
C. 20
D. 30
Answer : B

36. The factor of safety for
A. Steel and concrete are same
B. Steel is lower than that for concrete
C. Steel is higher than that for concrete
D. None of the above
Answer : B

37. Pick up the correct statement from the following:
A. Sand obtained from pits, is washed to remove clay and silt
B. Sand obtained from flooded pits, need not be washed before use
C. The chloride in sea shore sand and shingle may cause corrosion of reinforcement if the concrete is porous
D. All the above
Answer : D

38. 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

39. An aggregate is said to be flaky if its least dimension is less than
A. 1/5th of mean dimension
B. 2/5th of mean dimension
C. 3/5th of mean dimension
D. 4/5th of mean dimension
Answer : C

40. 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

41. 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

42. The datum temperature for maturity by Plowman, is
A. 23°C
B. 0°
C. - 5.6°C
D. - 11.7°C
Answer : D

43. Pick up the correct statement from the following:
A. The concrete gains strength due to hydration of cement
B. The concrete does not set at freezing point
C. The strength of concrete increases with its age
D. All the above
Answer : D

44. 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

45. 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

46. Pick up the incorrect statement from the following:
A. The degree of grinding of cement, is called fineness
B. The process of changing cement paste into hard mass, is known as setting of cement
C. The phenomenon by virtue of which cement does not allow transmission of sound, is known as soundness of cement
D. The heat generated during chemical reaction of cement with water, is known as heat of hydration
Answer : C

47. Workability improved by adding
A. Air-entraining agent
B. Foaming agent
C. Oily-agent
D. All the above
Answer : D

48. The high strength of rapid hardening cement at early stage, is due to its
A. Finer grinding
B. Burning at high temperature
C. Increased lime cement
D. Higher content of tricalcium
Answer : C

49. 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

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