SSC GD - Concrete Technology and Design 1000+ MCQ [Solved] PDF Download

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

2. Setting time of cement increases by adding
A. Gypsum
B. Hydrogen peroxide
C. Calcium chloride
D. Sodium oxide
Answer : A

3. To obtain cement dry powder, lime stones and shales or their slurry, is burnt in a rotary kiln at a temperature between
A. 1100° and 1200°C
B. 1200° and 1300°C
C. 1300° and 1400°C
D. 1400° and 1500°C
Answer : D

4. The compaction of concrete, improves
A. Density
B. Strength
C. Durability
D. All the above
Answer : D

5. 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

6. 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

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

8. Air entrainment in the concrete increases
A. Workability
B. Strength
C. The effects of temperature variations
D. The unit weight
Answer : A

9. 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

10. Transport of concrete by pumps, is done for a distance of
A. 100 m
B. 200 m
C. 300 m
D. 400 m
Answer : D

11. 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

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. The surface where two successive placements of concrete meet, is known as
A. Contraction joint
B. Expansion joint
C. Construction joint
D. Both (a) and (b)
Answer : C

14. 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

15. 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

16. 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

17. 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

18. The shrinkage of concrete
A. Is proportional to water content is the mix
B. Is proportional to cement concrete
C. Increases with age of concrete
D. All the above
Answer : D

19. 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

20. 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

21. 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

22. 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

23. In reinforced concrete footing on soil, the minimum thickness at edge should not be less than
A. 100 mm
B. 150 mm
C. 200 mm
D. 250 mm
Answer : B

24. The following proportion of the ingredients of concrete mix, is not in conformation to arbitrary method of proportioning
A. 1 : 1 : 2
B. 1 : 2 : 4
C. 1 : 3 : 6
D. 1 : 4 : 10
Answer : D

25. 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

26. 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

27. Percentage of pozzolanic material containing clay upto 80% used for the manufacture of pozzolana cement, is
A. 30 %
B. 40 %
C. 50 %
D. 60 %
Answer : A

28. The commercial name of white and coloured cement in India, is
A. Colorcrete
B. Silvicrete
C. Snowcem
D. All the above
Answer : D

29. In the design of a front counterfort in a counterfort retaining wall, the main reinforcement is provided on (i) Bottom face near counterfort (ii) Top face near counterfort (iii) Bottom face near centre of span (iv) Top face near centre of span The correct answer is
A. Only (i)
B. Only (ii)
C. Both (i) and (iv)
D. Both (ii) and (iii)
Answer : C

30. Workability of concrete mix with low water cement ratio is determined by
A. Tensile strength test
B. Slump test
C. Compaction factor test
D. Flexural strength test
Answer : C

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

32. For given water content, workability decreases if the concrete aggregates contain an excess of
A. Thin particles
B. Flat particles
C. Elongated particles
D. All the above
Answer : D

33. 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

34. 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

35. Pick up the correct statement from the following:
A. The maximum size of a coarse aggregate, is 75 mm and minimum 4.75 mm
B. The maximum size of the fine aggregate, is 4.75 mm and minimum 0.075 mm
C. The material having particles of size varying from 0.06 mm to 0.002 mm, is known as silt
D. All the above
Answer : D

36. 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

37. For the design of retaining walls, the minimum factor of safety against overturning is taken as
A. 1.5
B. 2.0
C. 2.5
D. 3.0
Answer : B

38. Ordinary concrete is not used for concrete grade
A. M 100
B. M 150
C. M 250
D. M 400
Answer : D

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

40. 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

41. The relation between modulus of rupture f_cr, splitting strength f_cs and direct tensile strength f_cl is given by
A. f_cr - f_cs = f_cl
B. f_cr > f_cs > f_cl
C. f_cr < f_cs < f_cl
D. f_cs > f_cr > f_cl
Answer : B

42. 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

43. According to Whitney's theory, ultimate strain of concrete is assumed to be
A. 0.03 %
B. 0.1 %
C. 0.3 %
D. 3 %
Answer : C

44. 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

45. Pick up the correct proportions of chemical ingredients of cement
A. Lime : Silica : Alumina : Iron oxide : 63 : 22 : 6 : 3
B. Silica : Lime : Alumina : Iron oxide : 63 : 22 : 6 : 3
C. Alumina : Silica : Lime : Iron oxide : 63 : 22 : 6 : 3
D. Iron oxide : Alumina : Silica : Lime : 63 : 22 : 6 : 3
Answer : A

46. In a spherical dome the hoop stress due to a concentrated load at crown is
A. Compressive everywhere
B. Tensile everywhere
C. Partly compressive and partly tensile
D. Zero
Answer : B

47. The individual variation between test strength of sample should not be more than
A. ± 5 % of average
B. ± 10 % of average
C. ± 15 % of average
D. ± 20 % of average
Answer : C

48. Workability of concrete is measured by
A. Vicat apparatus test
B. Slump test
C. Minimum void method
D. Talbot Richard test
Answer : B

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

50. 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