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

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

2. For a simply supported beam of span 15 m, the minimum effective depth to satisfy the vertical deflection limits should be
A. 600 mm
B. 750 mm
C. 900 mm
D. More than 1 m
Answer : B

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. According to IS : 382-1963, a good aggregate should be
A. Chemically inert
B. Sufficiently strong
C. Hard and durable
D. All the above
Answer : D

10. 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

11. Inert material of a cement concrete mix, is
A. Water
B. Cement
C. Aggregate
D. None of these
Answer : C

12. 1% of voids in a concrete mix would reduce its strength by about
A. 5 %
B. 10 %
C. 15 %
D. 20 %
Answer : A

13. Select the correct statement
A. Elastic modulus of high tensile steel is nearly the same as that of mild steel
B. Elastic modulus of high tensile steel is more than that of mild steel
C. Carbon percentage in high carbon steel is less than that in mild steel
D. High tensile steel is cheaper than mild steel
Answer : A

14. The increased cohesiveness of concrete, makes it
A. Less liable to segregation
B. More liable to segregation
C. More liable to bleeding
D. More liable for surface scaling in frosty weather
Answer : A

15. Le-Chatelier's apparatus is used for testing
A. Soundness of cement
B. Hardness of cement
C. Strength of cement
D. Durability of cement
Answer : A

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

17. Pick up the correct statement from the following:
A. Water cement paste hardens due to hydration
B. During hardening cement binds the aggregates together
C. Cement provides strength, durability and water tightness to the concrete
D. All the above
Answer : D

18. The maximum percentage of chemical ingredient of cement is that of
A. Magnesium oxide
B. Iron oxide
C. Silica
D. Lime
Answer : D

19. 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

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

21. 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

22. 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

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

24. 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

25. 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

26. Concrete containing
A. Siliceous aggregates, has higher co-efficient of expansion
B. Igneous aggregates, has intermediate coefficient of expansion
C. Lime stones, has lowest co-efficient of expansion
D. All the above
Answer : D

27. Concrete gains strength due to
A. Chemical reaction of cement with sand and coarse aggregates
B. Evaporation of water from concrete
C. Hydration of cement
D. All the above
Answer : C

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

29. 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

30. 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

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

32. Maximum quantity of water needed per 50 kg of cement for M 15 grade of concrete is
A. 28 liters
B. 30 liters
C. 32 liters
D. 34 liters
Answer : C

33. 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

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

35. To prevent segregation, the maximum height for placing concrete, is
A. 100 cm
B. 125 cm
C. 150 cm
D. 200 cm
Answer : A

36. 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

37. The light weight aggregates are obtained from
A. Sedimentary rocks
B. Metamorphic rocks
C. Igneous rocks
D. Volcanic source
Answer : D

38. Half of the main steel in a simply supported slab is bent up near the support at a distance of x from the center of slab bearing where x is equal to (Where l is the span)
A. l/3
B. l/5
C. l/7
D. l/10
Answer : C

39. 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

40. For road pavements, the cement generally used, is
A. Ordinary Portland cement
B. Rapid hardening cement
C. Low heat cement
D. Blast furnace slag cement
Answer : B

41. Separation of water or water sand cement from a freshly concrete, is known
A. Bleeding
B. Creeping
C. Segregation
D. Flooding
Answer : A

42. 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

43. 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

44. The diameter of the Vicat plunger is 10 mm and its length varies from
A. 20 mm to 30 mm
B. 30 mm to 40 mm
C. 40 mm to 50 mm
D. 50 mm to 60 mm
Answer : C

45. For a cantilever of effective depth of 0.5 m, the maximum span to satisfy vertical deflection limit is
A. 3.5 m
B. 4 m
C. 4.5 m
D. 5 m
Answer : A

46. 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