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

Thursday 9th of March 2023

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1. 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
2. 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
3. Pick up the incorrect statement from the following:
A. Admixtures accelerate hydration
B. Admixtures make concrete water proof
C. Admixtures make concrete acid proof
D. Admixtures give high strength
Answer : A
4. Log Angles machine is used to test the aggregate for
A. Crushing strength
B. Impact value
C. Abrasion resistance
D. Water absorption
Answer : C
5. Non-uniform compaction may cause the concrete
A. Porous
B. Non-homogeneous
C. Reduced strength
D. All the above
Answer : D
6. The cement becomes useless if its absorbed moisture content exceeds
A. 1 %
B. 2 %
C. 3 %
D. 5 %
Answer : D
7. Di-calcium silicate (C2S)
A. Hydrates rapidly
B. Generates less heat of hydration
C. Hardens rapidly
D. Provides less ultimate strength to cement
Answer : B
8. The final operation of finishing floors, is known as
A. Screeding
B. Floating
C. Trowelling
D. Finishing
Answer : C
9. 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
10. For an ordinary Portland cement
A. Residual does not exceed 10% when sieved through IS Sieve No. 9
B. Soundness varies from 5 to 10 mm
C. Initial setting time is not less than 30 minutes
D. Compressive stress after 7 days, is not less than 175 kg/cm2
Answer : C
11. Approximate value of shrinkage strain in concrete, is
A. 0.003
B. 0.0003
C. 0.00003
D. 0.03
Answer : B
12. The cement whose strength is a little lower than the ordinary cement during the first three months but attains afterwards the same strength, is known as
A. Low-heat Portland cement
B. Rapid hardening Portland cement
C. Portland blast slag cement
D. Portland pozzolana cement
Answer : A
13. High temperature
A. Increases the strength of concrete
B. Decreases the strength of concrete
C. Has no effect on the strength of concrete
D. None of these
Answer : B
14. Select the incorrect statement
A. Lean mixes bleed more as compared to rich ones.
B. Bleeding can be minimized by adding pozzolana finer aggregate
C. Bleeding can be increased by addition 'of calcium chloride
D. None of the above
Answer : D
15. Air entrainment in the concrete increases
A. Workability
B. Strength
C. The effects of temperature variations
D. The unit weight
Answer : A
16. 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
17. 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
18. 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
19. Due to circumferential action of the spiral in a spirally reinforced column
A. Capacity of column is decreased
B. Ductility of column reduces
C. Capacity of column is decreased but ductility of column increases
D. Both the capacity of column and ductility of column increase
Answer : D
20. 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
21. 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
22. Higher workability of concrete is required if the structure is
A. Made with cement concrete
B. Thick and reinforced
C. Thin and heavily reinforced
D. Thick and heavily reinforced
Answer : D
23. Workability of concrete is inversely proportional to
A. Time of transit
B. Water-cement ratio
C. The air in the mix
D. Size of aggregate
Answer : A
24. Modulus of elasticity of steel as per IS: 4561978 shall be taken as
A. 20 kN/cm²
B. 200 kN/cm²
C. 200 kN/mm²
D. 2 × 106 N/cm²
Answer : C
25. 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
26. 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
27. 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
28. Pick up the correct statement from the following:
A. An increase in water content must be accompanied by an increase in cement content
B. Angular and rough aggregates reduce the workability of the concrete
C. The slump of the concrete mix decreases due to an increase in temperature
D. All the above
Answer : D
29. 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
30. 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
31. 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
32. Examine the following statements: (i) Factor of safety for steel should be based on its yield stress, (ii) Factor of safety for steel should be based on its ultimate stress, (iii) Factor of safety for concrete should be based on its yield stress, (iv) Factor of safety for concrete should be based on its ultimate stress. The correct statements are
A. (i) and (iii)
B. (i) and (iv)
C. (ii) and (iii)
D. (ii) and (iv)
Answer : B
33. Concrete mainly consists of
A. Cement
B. Aggregates
C. Water
D. All the above
Answer : D
34. The operation of removing humps and hollows of uniform concrete surface, is known as
A. Floating
B. Screeding
C. Trowelling
D. Finishing
Answer : B
35. On a grading curve, the gap grading is represented by
A. A horizontal line
B. A vertical line
C. N.W. inclined line
D. N.E. inclined line
Answer : A
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. Minimum thickness of load bearing RCC wall should be
A. 50 mm
B. 100 mm
C. 150 mm
D. 200 mm
Answer : B
38. Curing a concrete for long period ensures better
A. Volume stability
B. Strength
C. Water resistance
D. All the above
Answer : D
39. 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
40. 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
41. An aggregate which passes through 25 mm I.S. sieve and is retained on 20 mm sieve, is said to be flaky if its least dimension is less than
A. 22.5 mm
B. 18.5 mm
C. 16.5 mm
D. 13.5 mm
Answer : D
42. 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
43. 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
44. If the effective plan area of a warehouse is 54 sq. m, and maximum height of piles permitted is 270 cm, the number of cement bags to be stored, is
A. 2000 bags
B. 2200 bags
C. 2400 bags
D. 2700 bags
Answer : D
45. Which of the following losses of pre-stress occurs only in pretensioning and not in post-tensioning?
A. Elastic shortening of concrete
B. Shrinkage of concrete
C. Creep of concrete
D. Loss due to friction
Answer : A
46. 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
47. Maximum percentage reinforcement in case of slabs is limited to
A. 2
B. 4
C. 6
D. 8
Answer : B
48. If the slump of a concrete mix is 60 mm, its workability is
A. Very low
B. Low
C. Medium
D. High
Answer : C
49. The bulk density of aggregates, depends upon
A. Shape
B. Grading
C. Compaction
D. All the above
Answer : D
50. The light weight aggregates are obtained from
A. Sedimentary rocks
B. Metamorphic rocks
C. Igneous rocks
D. Volcanic source
Answer : D

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