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

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

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

3. 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

4. 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

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. 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

7. 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

8. While compacting the concrete by a mechanical vibrator, the slump should not exceed
A. 2.5 cm
B. 5.0 cm
C. 7.5 cm
D. 10 cm
Answer : B

9. 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

10. The ratio of various ingredients (cement, sand, aggregates) in concrete of grade M 200, is
A. 1 : 2 : 4
B. 1 : 3 : 6
C. 1 : 1 ½ : 3
D. 1 : 1 : 2
Answer : C

11. 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

12. 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

13. For preparing a test-specimen, it is necessary
A. To mix cement and fine aggregate by dry hand
B. To mix coarse aggregates
C. To mix water to the cement, fine aggregates and coarse aggregates
D. All the above
Answer : D

14. 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

15. 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

16. The bulk density of aggregates, depends upon
A. Shape
B. Grading
C. Compaction
D. All the above
Answer : D

17. Hardening of cement occurs at
A. Rapid rate during the first few days and afterwards it continues to increase at a decreased rate
B. Slow rate during the first few days and afterwards it continues to increase at a rapid rate
C. Uniform rate throughout its age
D. None of these
Answer : D

18. During erection, the pile of length l is supported by a crane at a distance of
A. 0.207 l
B. 0.293 l
C. 0.707 l
D. 0.793 l From the driving end of pile which rests on the ground
Answer : C

19. 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

20. The concrete mix which causes difficulty in obtaining a smooth finish, possess
A. Segregation
B. Internal friction
C. Hardness
D. Bleeding
Answer : C

21. The main reinforcement in the heel of a T-shaped R.C. retaining wall is provided on
A. Top face perpendicular to wall
B. Bottom face perpendicular to wall
C. Both top and bottom faces perpendicular to wall
D. None of the above
Answer : A

22. Pick up the incorrect statement from the following:
A. Admixtures accelerate hydration
B. Admixtures make concrete water proof
C.D. Admixtures give high strength
Answer : A

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

24. 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

25. 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

26. 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

27. C.R.R.I. charts are used to obtain a relationship between strength of concrete and
A. Water cement ratio
B. Workability
C. Grading of aggregate
D. Fineness modulus
Answer : A

28. Curing a concrete for long period ensures better
A. Volume stability
B. Strength
C. Water resistance
D. All the above
Answer : D

29. Pick up the correct statement from the following:
A. Cement should be mixed for at least one minute
B. 10% of water is placed in the rotating drum before adding dry material
C. 10% of water is added after placing the other ingredients in the drum
D. All the above
Answer : D

30. In working stress design, permissible bond stress in the case of deformed bars is more than that in plain bars by
A. 10 %
B. 20 %
C. 30 %
D. 40 %
Answer : D

31. According to Water-Cement Ratio Law, the strength of workable plastic concrete
A. Depends upon the amount of water used in the mix
B. Does not depend upon the quality of cement mixed with aggregates
C. Does not depend upon the quantity of cement mixed with aggregates
D. All the above
Answer : D

32. 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

33. Pick up the correct statement from the following:
A. Water enables chemical reaction to take place with cement
B. Water lubricates the mixture of gravel, sand and cement
C. Strength of concrete structure largely depends upon its workability
D. All the above
Answer : D

34. 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

35. The minimum cover to the ties or spirals should not be less than
A. 15 mm
B. 20 mm
C. 25 mm
D. 50 mm
Answer : C

36. 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

37. The main object of compaction of concrete, is:
A. To eliminate air holes
B. To achieve maximum density
C. To provide intimate contact between the concrete and embedded materials
D. All the above
Answer : D

38. 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

39. Workability improved by adding
A. Fly ash
B. Hydrated lime
C. Calcium chloride
D. All the above
Answer : D

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

41. For a continuous slab of 3 m × 3.5 m size, the minimum overall depth of slab to satisfy vertical deflection limits is
A. 50 mm
B. 75 mm
C. 100 mm
D. 120 mm
Answer : B

42. How long will it take for the concrete to achieve 100% of its strength?
A. 7 days
B. 14 days
C. 21 days
D. 28 days
Answer : D

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

44. Pick up the incorrect statement applicable to the field test of good cement.
A. When one thrusts one's hand into a bag of cement, one should feel warm
B. The colour of the cement is bluish
C. By rubbing cement in between fingers, one should feed rough
D. All the above
Answer : D

45. 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

46. Bulking of sand is
A. Mixing of different sizes of sand particles
B. Mixing of lime with sand
C. Maximum water with sand
D. Swelling of sand when wetted
Answer : D

47. Shrinkage of concrete depends upon
(i) Humidity of atmosphere
(ii) Passage of time
(iii) Stress The correct answer is
A. (i) and (ii)
B. (ii) and (iii)
C. Only (iii)
D. All (i), (ii) and (iii)
Answer : A

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

49. The permissible diagonal tensile stress in reinforced brick work is
A. About 0.1 N/mm²
B. Zero
C. 0.3 N/mm² to 0.7 N/mm²
D. About 1.0 N/mm²
Answer : A

50. 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