1000+ Concrete Technology and Design MCQ for CAT [Solved]

1. Allowable shear strength of concrete, depends upon
A. Shear strength
B. Tensile strength
C. Compressive strength
D. None of these
Answer : A

2. 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

3. 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

4. The grade of concrete not recommended by I.S. : 456, is
A. M 100
B. M 200
C. M 300
D. M 500
Answer : D

5. 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

6. 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

7. 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

8. Ordinary Portland cement is manufactured from
A. Lime stone and clay
B. Gypsum and lime
C. Pozzolana
D. Lime, pozzolana and clay
Answer : B

9. Slump test of concrete is a measure of its
A. Consistency
B. Compressive strength
C. Tensile strength
D. Impact value
Answer : A

10. 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

11. 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

12. 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

13. For a concrete mix 1:3:6 and water cement ratio 0.6 both by weight, the quantity of water required per bag, is
A. 10 kg
B. 12 kg
C. 14 kg
D. 16 kg
Answer : C

14. 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

15. 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

16. The recommended value of modular ratio for reinforced brick work is
A. 18
B. 30
C. 40
D. 58
Answer : C

17. 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

18. The preliminary test is repeated if the difference of compressive strength of three test specimens, exceeds
A. 5 kg/cm²
B. 8 kg/cm²
C. 10 kg/cm²
D. 15 kg/cm²
Answer : D

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

20. The temperature reinforcement in the vertical slab of a T-shaped R.C. retaining wall is
A. Not needed
B. Provided equally on inner and front faces
C. Provided more on inner face than on front face
D. Provided more on front face than on inner face
Answer : D

21. 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

22. 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

23. 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

24. Pick up the incorrect statement from the following:
A. The bottom and top ends of slump mould are parallel to each other
B. The axis of the mould is perpendicular to the end faces
C. The internal surface of the mould is kept clean and free from set cement
D. The mould is in the form of a frustum of hexagonal pyramid
Answer : D

25. For given workability the grading requiring the least amount of water is one that gives
A. Greatest surface area for the given cement and aggregates
B. Least surface area for the given cement and aggregates
C. Least weight for the given cement and aggregates
D. Greatest weight for the given cement and aggregates
Answer : A

26. The high strength of rapid hardening cement at early stage, is due to its
A. Finer grinding
B. Burning at high temperature
C. Increased lime cement
D. Higher content of tricalcium
Answer : C

27. If 20 kg of coarse aggregate is sieved through 80 mm, 40 mm, 20 mm, 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 300 micron and 150 micron standard sieves and the weights retained are 0 kg, 2 kg, 8 kg, 6 kg, 4 kg respectively, the fineness modulus of the aggregate, is
A. 7.30
B. 7.35
C. 7.40
D. 7.45
Answer : C

28. 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

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

30. While designing an air entrained concrete
A. Water cement ratio is reduced
B. Proportion of aggregates is reduced
C. An allowance for the entrained air is made
D. All the above
Answer : D

31. The approximate value of the ratio between direct tensile strength and flexural strength is
A. 0.33
B. 0.5
C. 0.75
D. 1.0
Answer : B

32. 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

33. When shear stress exceeds the permissible limit in a slab, then it is reduced by
A. Increasing the depth
B. Providing shear reinforcement
C. Using high strength steel
D. Using thinner bars but more in number
Answer : A

34. Non-uniform compaction may cause the concrete
A. Porous
B. Non-homogeneous
C. Reduced strength
D. All the above
Answer : D

35. For a reinforced concrete section, the shape of shear stress diagram is
A. Wholly parabolic
B. Wholly rectangular
C. Parabolic above neutral axis and rectangular below neutral axis
D. Rectangular above neutral axis and parabolic below neutral axis
Answer : C

36. Due to shrinkage stresses, a simply supported beam having reinforcement only at bottom tends to
A. Deflect downward
B. Deflect upward
C. Deflect downward or upward
D. None of the above
Answer : A

37. Concrete mainly consists of
A. Cement
B. Aggregates
C. Water
D. All the above
Answer : D

38. Minimum grade of concrete to be used in reinforced concrete as per IS: 4561978 is
A. M 15
B. M 20
C. M 10
D. M 25
Answer : A

39. Pre-stress loss due to friction occurs
A. Only in post-tensioned beams
B. Only in pre-tensioned beams
C. In both post-tensioned and pre-tensioned beams
D. None of the above
Answer : A

40. Most common method of pre-stressing used for factory production is
A. Long line method
B. Freyssinet system
C. Magnel-Blaton system
D. Lee-Macall system
Answer : A

41. An aggregate is known as cyclopean aggregate if its size is more than
A. 4.75 mm
B. 30 mm
C. 60 mm
D. 75 mm
Answer : D

42. Gypsum is added for
A. Colour
B. Strength
C. Controlling setting time
D. None of these
Answer : C

43. W_p and W_f are the weights of a cylinder containing partially compacted and fully compacted concrete. If the compaction factor (W_p/W_f) is 0.95, the workability of concrete is
A. Extremely low
B. Very low
C. Low
D. High
Answer : D

44. The bulk density of aggregates does not depend upon:
A. Size and shape of aggregates
B. Specific gravity of aggregates
C. Grading of aggregates
D. Size and shape of the container
Answer : D

45. 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

46. Slump test of concrete is a measure of its
A. Consistency
B. Compressive strength
C. Tensile strength
D. Impact value
Answer : A

47. 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

48. 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

49. If aggregates completely pass through a sieve of size 75 mm and are retained on a sieve of size 60 mm, the particular aggregate will be flaky if its minimum dimension is less than
A. 20.5 mm
B. 30.5 mm
C. 40.5 mm
D. 50.5 mm
Answer : C

50. 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