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

1. 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

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

3. 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

4. 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

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

6. For compacting plain concrete road surface of thickness less than 20 cm, we use
A. Internal vibrator
B. Screed vibrator
C. Form vibrator
D. None of these
Answer : B

7. In case of hand mixing of concrete, the extra cement to be added is
A. 5 %
B. 10 %
C. 15 %
D. 20 %
Answer : B

8. 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

9. M10 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 : A

10. Construction joints are generally provided in concrete
A. Roads
B. Retaining walls
C. Lining of canals
D. All the above
Answer : D

11. 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

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

13. Sinking of an intermediate support of a continuous beam (i) Reduces the negative moment at support (ii) Increases the negative moment at support (iii) Reduces the positive moment at center of span (iv) Increases the positive moment at center of span The correct answer is
A. (i) and (iii)
B. (i) and (iv)
C. (ii) and (iii)
D. (ii) and (iv)
Answer : B

14. Curing of pavements, floors, roofs and slabs, is done by
A. Membrane method
B. Ponding method
C. Covering surface with bags
D. Sprinkling water method
Answer : B

15. According to Whitney's theory, depth of stress block for a balanced section of a concrete beam is limited to
A. 0.43 d
B. 0.537 d
C. 0.68 d
D. 0.85 d Where d is effective depth of beam
Answer : B

16. The strength and quality of concrete, depend upon:
A. Grading of aggregates
B. Surface area of aggregates
C. Shape of aggregates
D. All the above
Answer : D

17. 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

18. The design yield stress of steel according to IS: 4561978 is: (Where f_y is the characteristic yield strength of steel)
A. 0.37 f_y
B. 0.57 f_y
C. 0.67 f_y
D. 0.87 f_y
Answer : D

19. 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

20. The load carrying capacity of a helically reinforced column as compared to that of a tied column is about
A. 5 % less
B. 10 % less
C. 5 % more
D. 10 % more
Answer : C

21. After casting, an ordinary cement concrete on drying
A. Expands
B. Mix
C. Shrinks
D. None of these
Answer : C

22. Ordinary Portland cement is manufactured from
A. Lime stone and clay
B. Gypsum and lime
C. Pozzolana
D. Lime, pozzolana and clay
Answer : B

23. Cement used for normal concrete construction, is obtained by burning a mixture of
A. Siliceous and argillaceous materials
B. Argillaceous and calcareous materials
C. Siliceous and calcareous materials
D. Siliceous, argillaceous and calcareous materials
Answer : D

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

25. 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

26. Water cement ratio is generally expressed in volume of water required per
A. 10 kg
B. 20 kg
C. 30 kg
D. 50 kg
Answer : D

27. The diameter of ties in a column should be
A. More than or equal to one fourth of diameter of main bar
B. More than or equal to 5 mm
C. More than 5 mm but less than one-fourth of diameter of main bar
D. More than 5 mm and also more than one-fourth of diameter of main bar
Answer : D

28. 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

29. The ratio of the length to breadth of a wooden float, is
A. 4.5
B. 5.5
C. 6.5
D. 7.5
Answer : D

30. If the engineer-in-charge approves, the 10 cm cubes may be used for the work test of concrete provided maximum nominal size of aggregate, does not exceed
A. 10 cm
B. 15 cm
C. 20 cm
D. 25 cm
Answer : C

31. The commonly used material in the manufacture of cement is
A. Sand stone
B. Slate
C. Lime stone
D. Graphite
Answer : C

32. If a grading curve is horizontal between the portions of 20 mm I.S. Sieve and 4.75 mm I.S. Sieve, the graded aggregates do not contain
A. 20 mm particles
B. 10 mm particles
C. 4.75 mm particles
D. All the above
Answer : D

33. 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

34. Pick up the correct statement from the following:
A. Construction joints are necessarily planned for their locations
B. Expansion joints are provided to accommodate thermal expansion
C. Construction joints are provided to control shrinkage cracks
D. All the above
Answer : D

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

36. 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

37. 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

38. Modulus of rupture of concrete is a measure of
A. Flexural tensile strength
B. Direct tensile strength
C. Compressive strength
D. Split tensile strength
Answer : A

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

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

41. 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

42. 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

43. 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

44. The bulk density of aggregates does not depend upon:
A. Size and shape of aggregates
B. Specific gravity of aggregates
C. Grading of aggregates
D. Size and shape of the container
Answer : D

45. 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

46. Proper batching ensures
A. Economy
B. Durability
C. Workability
D. All the above
Answer : D

47. 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

48. 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

49. 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

50. In a ring beam subjected to uniformly distributed load (i) Shear force at mid span is zero (ii) Shear force at mid span is maximum (iii) Torsion at mid span is zero (iv) Torsion at mid span is maximum The correct answer is
A. (i) and (iii)
B. (i) and (iv)
C. (ii) and (iii)
D. (ii) and (iv)
Answer : A