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

1. 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

2. If the size of panel in a flat slab is 6 m × 6 m, then as per Indian Standard Code, the widths of column strip and middle strip are
A. 3.0 m and 1.5 m
B. 1.5 m and 3.0 m
C. 3.0 m and 3.0 m
D. 1.5 m and 1.5 m
Answer : C

3. 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

4. The aggregate impact value of the aggregate used in
A. Building concrete is less than 45
B. Road pavement concrete is less than 30
C. Runway concrete is less than 30
D. All the above
Answer : D

5. For quality control of Portland cement, the test essentially done is
A. Setting time
B. Tensile strength
C. Consistency
D. All the above
Answer : D

6. 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

7. While designing the pile as a column, the end conditions are nearly
A. Both ends hinged
B. Both ends fixed
C. One end fixed and other end hinged
D. One end fixed and other end free
Answer : C

8. 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

9. 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

10. 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

11. The entrained air in concrete
A. Increases workability
B. Decreases workability
C. Decreases resistance to weathering
D. Increases strength
Answer : A

12. When shear stress exceeds the permissible limit in a slab, then it is reduced by
A. Increasing the depth
B. Providing shear reinforcement
C. Using high strength steel
D. Using thinner bars but more in number
Answer : A

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. Admixtures which cause early setting and hardening of concrete are called
A. Workability admixtures
B. Accelerators
C. Retarders
D. Air entraining agents
Answer : B

15. 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

16. 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

17. 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

18. 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

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

20. 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

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

22. Construction joints are provided
A. Where B.M. and S.F. are small
B. Where the member is supported by other member
C. At 18 m apart in huge structures
D. All the above
Answer : D

23. High carbon content in the steel causes
A. Decrease in tensile strength but increase in ductility
B. Increase in tensile strength but decrease in ductility
C. Decrease in both tensile strength and ductility
D. Increase in both tensile strength and ductility
Answer : B

24. 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

25. 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

26. Specified compressive strength of concrete is obtained from cube tests at the end of
A. 3 days
B. 7 days
C. 21 days
D. 28 days
Answer : D

27. For a reinforced concrete section, the shape of shear stress diagram is
A. Wholly parabolic
B. Wholly rectangular
C. Parabolic above neutral axis and rectangular below neutral axis
D. Rectangular above neutral axis and parabolic below neutral axis
Answer : C

28. The property of fresh concrete, in which the water in the mix tends to rise to the surface while placing and compacting, is called
A. Segregation
B. Bleeding
C. Bulking
D. Creep
Answer : B

29. 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

30. 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

31. 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

32. 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

33. 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

34. 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

35. 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

36. 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

37. 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

38. Stress strain curve of high tensile steel
A. Has a definite yield point
B. Does not show definite yield point but yield point is defined by 0.1% proof stress
C. Does not show definite yield point but yield point is defined by 0.2% proof stress
D. Does not show definite yield point but yield point is defined by 2% proof stress,
Answer : C

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

40. For the construction of thin R.C.C. structures, the type of cement to be avoided, is
A. Ordinary Portland cement
B. Rapid hardening cement
C. Low heat cement
D. Blast furnace slag cement
Answer : D

41. For preparing ordinary concrete, the quantity of water used, is
A. 5% by weight of aggregates plus 20% of weight of cement
B. 10% by weight of aggregates plus 10% of weight of cement
C. 5% by weight of aggregates plus 30% of weight of cement
D. 30% by weight of aggregates plus 10% of weight of cement
Answer : C

42. For the construction of cement concrete floor, the maximum permissible size of aggregate, is
A. 4 mm
B. 6 mm
C. 8 mm
D. 10 mm
Answer : D

43. 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

44. 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

45. The percentage of voids in cement is approximately
A. 25 %
B. 40 %
C. 60 %
D. 80 %
Answer : B

46. 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

47. Due to shrinkage stresses, a simply supported beam having reinforcement only at bottom tends to
A. Deflect downward
B. Deflect upward
C. Deflect downward or upward
D. None of the above
Answer : A

48. Pick up the incorrect statement from the following:
A. A rich mix of concrete possesses higher strength than that a lean mix of desired workability with excessive quantity of water
B. The strength of concrete decreases as the water cement ratio increases
C. Good compaction by mechanical vibrations, increases the strength of concrete
D. None of these
Answer : A

49. Addition of pozzolana to ordinary port land cement, causes
A. Decrease in early strength
B. Reduction in chemical action with sulphates
C. Increase in shrinkage
D. All the above
Answer : D

50. 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