Concrete Technology and Design 1000+ MCQ with answer for LIC AAO

1. In the method of voids for determination of the quantity of cement paste, it is assumed that
A. Voids in coarse aggregates are filled by fine aggregates
B. Voids in fine aggregates are filled by the cement paste
C. Volume of fine aggregates is equal to total voids in coarse aggregates plus 10% extra
D. All the above
Answer : D

2. For a slab supported on its four edges with corners held down and loaded uniformly, the Marcus correction factor to the moments obtained by Grashoff Rankine's theory
A. Is always less than 1
B. Is always greater than 1
C. Can be more than 1
D. Can be less than 1
Answer : A

3. Pick up the correct statement from the following:
A. Lime in excess, causes the cement to expand and disintegrate
B. Silica in excess, causes the cement to set slowly
C. Alumina in excess, reduces the strength of the cement
D. All the above
Answer : D

4. 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

5. 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

6. You are asked to construct a massive dam, the type of cement you will use, is
A. Ordinary Portland cement
B. Rapid hardening cement
C. Low heat cement
D. Blast furnace slag cement
Answer : C

7. 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

8. W_p and W_f are the weights of a cylinder containing partially compacted and fully compacted concrete. If the compaction factor (W_p/W_f) is 0.95, the workability of concrete is
A. Extremely low
B. Very low
C. Low
D. High
Answer : D

9. Pick up the incorrect statement from the following:
A. With passage of time, the strength of cement increases
B. With passage of time, the strength of cement decreases
C. After a period of 24 months, the strength of cement reduces to 50%
D. The concrete made with storage deteriorated cement, gains strength with time
Answer : A

10. 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

11. The process of proper and accurate measurement of concrete ingredients for uniformity of proportion, is known
A. Grading
B. Curing
C. Mixing
D. Batching
Answer : D

12. For batching 1:3:6 concrete mix by volume, the ingredients required per bag of 50 kg cement, are:
A. 70 litres of sand and 120 litres of aggregates
B. 70 kg of sand and 140 litres of aggregates
C. 105 litres of sand and 140 litres of aggregates
D. 105 litres of sand and 210 litres of aggregates
Answer : D

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

14. 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

15. The factor which affects workability, is
A. Water content and its temperature
B. Shape and size of the aggregates
C. Air entraining agents
D. All the above
Answer : D

16. A concrete using an air entrained cement
A. Has strength less than 10% to 15%
B. Has more resistance to weathering
C. Is more plastic and workable
D. Is free from segregation and bleeding
Answer : C

17. 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

18. The type of aggregates of same nominal size, which contain less voids when compacted, are
A. Rounded spherical
B. Irregular
C. Flaky
D. None of these
Answer : A

19. Pick up the incorrect statement from the following:
A. Tricalcium silicate (C3S) hydrates rapidly
B. Tricalcium silicate (C3S) generates more heat of hydration
C. Tricalcium silicate (C3S) develops early strength
D. Tricalcium silicate (C3S) has more resistance to sulphate attack
Answer : D

20. 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

21. 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

22. 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

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

24. Assertion A : The load factor for live load is greater than that for dead load. Reason R : The live loads are more uncertain than dead loads. Select your answer based on the coding system given below:
A. Both A and R is true and R is the correct explanation of A
B. Both A and R is true but R is not the correct explanation of A
C. A is true but R is false
D. A is false but R is true
Answer : A

25. The temperature reinforcement in the vertical slab of a T-shaped R.C. retaining wall is
A. Not needed
B. Provided equally on inner and front faces
C. Provided more on inner face than on front face
D. Provided more on front face than on inner face
Answer : D

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

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

28. 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

29. 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

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

31. Strength of concrete with passage of time
A. Increases
B. Decreases
C. Fluctuates
D. Remains constant
Answer : A

32. If the various concrete ingredients i.e. cement, sand and aggregates are in the ratio of 1:3:6, the grade of concrete, is
A. M 100
B. M 150
C. M 200
D. M 250
Answer : A

33. The individual variation between test strength of sample should not be more than
A. ± 5 % of average
B. ± 10 % of average
C. ± 15 % of average
D. ± 20 % of average
Answer : C

34. 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

35. 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

36. 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

37. 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

38. The type of aggregates not suitable for high strength concrete and for pavements subjected to tension, is
A. Rounded aggregate
B. Irregular aggregate
C. Angular aggregate
D. Flaky aggregate
Answer : A

39. In T-shaped R C. retaining walls, the main reinforcement in the stem is provided on
A. The front face in one direction
B. The front face in both directions
C. The inner face in one direction
D. The inner face in both directions
Answer : C

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

41. If a beam fails in bond, then its bond strength can be increased most economically by
A. Increasing the depth of beam
B. Using thinner bars but more in number
C. Using thicker bars but less in number
D. Providing vertical stirrups
Answer : B

42. The specifications of a cement bag for storage, are
A. Weight 50 kg
B. Height 18 cm
C. Plan area 3000 sq. cm
D. All the above
Answer : D

43. 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

44. Workability of concrete is measured by
A. Vicat apparatus test
B. Slump test
C. Minimum void method
D. Talbot Richard test
Answer : B

45. As compared to ordinary Portland cement, use of pozzolana cement
A. Reduces workability
B. Increases bleeding
C. Increases shrinkage
D. Increases strength
Answer : C

46. In a spherical dome the hoop stress due to a concentrated load at crown is
A. Compressive everywhere
B. Tensile everywhere
C. Partly compressive and partly tensile
D. Zero
Answer : B

47. 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

48. An excess of flaky particles in concrete aggregates
A. Decreases the workability
B. Increases the quantity of water and sand
C. More than 15% are not desirable
D. All the above
Answer : D

49. Pick up the correct statement from the following:
A. Bulking of sand is caused due to formation of a thin film of surface moisture
B. Fine sand bulks more than coarse sand
C. The volume of fully saturated sand, is equal to the volume of dry and loose sand
D. All the above
Answer : D

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