Concrete Technology and Design 1000+ MCQ with answer for RRB JE

1. The maximum amount of dust which may be permitted in aggregates is
A. 5% of the total aggregates for low workability with a coarse grading
B. 10% of the total aggregates for low workability with a fine grading
C. 20% of the total aggregates for a mix having high workability with fine grading
D. All the above
Answer : D

2. An aggregate is said to be flaky, if its least dimension is less than
A. 2/3 mean dimension
B. 3/4 mean dimension
C. 3/5 mean dimension
D. 5/8 mean dimension
Answer : C

3. Critical section for shear in case of flat slabs is at a distance of
A. Effective depth of slab from periphery of column/drop panel
B. d/2 from periphery of column/capital/ drop panel
C. At the drop panel of slab
D. At the periphery of column
Answer : B

4. 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

5. The 28 days cube strength of mass concrete using aggregates of maximum size 5 cm for gravity dams should be
A. Between 150 to 300 kg/cm²
B. Between 350 to 600 kg/cm²
C. Between 150 to 500 kg/cm²
D. Below 200 kg/cm²
Answer : D

6. Permissible compressive strength of M 150 concrete grade is
A. 100 kg/cm2
B. 150 kg/cm2
C. 200 kg/cm2
D. 250 kg/cm2
Answer : C

7. 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

8. 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

9. 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

10. 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

11. 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

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

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

14. 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

15. 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

16. 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

17. Pick up the correct statement from the following:
A. The weight of ingredients of concrete mix, is taken in kilograms
B. Water and aggregates are measured in litres
C. 20 bags of cement make one tonne
D. All the above
Answer : D

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

19. An ideal ware house, is provided
A. Water proof masonry walls
B. Water proof roof
C. Few windows which remain generally closed
D. All the above
Answer : D

20. 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

21. The size of fine aggregates does not exceed
A. 2.75 mm
B. 3.00 mm
C. 3.75 mm
D. 4.75 mm
Answer : D

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

23. 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

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

25. If X, Y and Z are the fineness modulli of coarse, fine and combined aggregates, the percentage (P) of fine aggregates to combined aggregates, is
A. P = [(Z - X)/(Z - Y)] × 100
B. P = [(X - Z)/(Z - Y)] × 100
C. P = [(X - Z)/(Z + Y)] × 100
D. P = [(Z + X)/(Z - Y)] × 100
Answer : B

26. The internal dimensions of a ware house are 15 m × 5.6 m, and the maximum height of piles is 2.70 m, the maximum number of bags to be stored in two piles, are
A. 1500 bags
B. 2000 bags
C. 2500 bags
D. 3000 bags
Answer : D

27. 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

28. In slump test, each layer of concrete is compacted by a steel rod 60 cm long and of 16 mm diameter for
A. 20 times
B. 25 times
C. 30 times
D. 50 times
Answer : B

29. While designing the pile as a column, the end conditions are nearly
A. Both ends hinged
B. Both ends fixed
C. One end fixed and other end hinged
D. One end fixed and other end free
Answer : C

30. If the depth of moist sand in a cylinder is 15 cm and the depth of the sand when fully inundated with water is 12 cm, the bulking of the moist sand, is
A. 10 %
B. 12 %
C. 15 %
D. 25 %
Answer : D

31. The risk of segregation is more for
A. Wetter mix
B. Larger proportion of maximum size aggregate
C. Coarser grading
D. All the above
Answer : D

32. 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

33. 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

34. Slump test is done for
A. Clay
B. Sand
C. Lime
D. Concrete
Answer : D

35. A concrete having a slump of 6.5 cm, is said to be
A. Dry
B. Earth moist
C. Semi-plastic
D. Plastic
Answer : D

36. To ensure constant moisture content in aggregates
A. Area of each aggregate pile should be large
B. Height of each aggregate pile should not exceed 1.50 m
C. Aggregate pile should be left for 24 hours before aggregates are used
D. All the above
Answer : D

37. 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

38. 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

39. 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

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

41. The minimum percentage of chemical ingredient of cement is that of
A. Magnesium oxide
B. Iron oxide
C. Alumina
D. Lime
Answer : A

42. If the storey height is equal to length of RCC wall, the percentage increase in strength is
A. 0
B. 10
C. 20
D. 30
Answer : B

43. According to I.S. : 456, the number of grades of concrete mixes, is
A. 3
B. 4
C. 5
D. 7
Answer : D

44. Water required per bag of cement, is
A. 7 kg
B. 14 kg
C. 21 kg
D. 35 kg
Answer : D

45. If the slump of a concrete mix is 60 mm, its workability is
A. Very low
B. Low
C. Medium
D. High
Answer : C

46. Pick up the correct statement from the following:
A. Higher workability indicates unexpected increase in the moisture content
B. Higher workability indicates deficiency of sand
C. If the concrete mix is dry, the slump is zero
D. All the above
Answer : D

47. As compared to ordinary Portland cement, high alumina cement has
A. Higher initial setting time but lower final setting time
B. Lower initial setting time but higher final setting time
C. Higher initial and final setting times
D. Lower initial and final setting times
Answer : A

48. The centroid of compressive force, from the extreme compression fiber, in limit state design lies at a distance of (Where x_u is the depth of neutral axis at the limit state of collapse)
A. 0.367 x_u
B. 0.416 x_u
C. 0.446 x_u
D. 0.573 x_u
Answer : B

49. To minimise the effect of differential settlement, the area of a footing should be designed for
A. Dead load only
B. Dead load + live load
C. Dead load + fraction of live load
D. Live load + fraction of dead load
Answer : C

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