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

1. 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

2. Pick up the correct statement from the following:
A. Bulking of sand is caused due to formation of a thin film of surface moisture
B. Fine sand bulks more than coarse sand
C. The volume of fully saturated sand, is equal to the volume of dry and loose sand
D. All the above
Answer : D

3. 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

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

5. Pick up the correct statement from the following:
A. Construction joints are necessarily planned for their locations
B. Expansion joints are provided to accommodate thermal expansion
C. Construction joints are provided to control shrinkage cracks
D. All the above
Answer : D

6. 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

7. 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

8. Separation of water or water sand cement from a freshly concrete, is known
A. Bleeding
B. Creeping
C. Segregation
D. Flooding
Answer : A

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

10. 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

11. Which of the following has high tensile strength?
A. Plain hot rolled wires
B. Cold drawn wires
C. Heat treated rolled wires
D. All have same tensile strength
Answer : B

12. 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

13. 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

14. 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

15. 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

16. Maximum distance between expansion joints in structures as per IS: 456 1978 is
A. 20 m
B. 30 m
C. 45 m
D. 60 m
Answer : C

17. 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

18. Diagonal tension in a beam
A. Is maximum at neutral axis
B. Decreases below the neutral axis and increases above the neutral axis
C. Increases below the neutral axis and decreases above the neutral axis
D. Remains same
Answer : C

19. 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

20. Pick up the correct statement from the following:
A. According to the petrological characteristics, concrete aggregates are classified as heavy weight, normal weight and light weight
B. According to the shape of the particles, concrete aggregates are classified as rounded irregular, angular and flaky
C. According to the surface texture of the particles, the concrete aggregates are classified as glassy, smooth, granular, rough, crystalline, honey combed and porous
D. All the above
Answer : D

21. Pozzolana cement is used with confidence for construction of
A. Dams
B. Massive foundations
C. R.C.C. structures
D. All the above
Answer : D

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

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. Water cement ratio is generally expressed in volume of water required per
A. 10 kg
B. 20 kg
C. 30 kg
D. 50 kg
Answer : D

25. 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

26. 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

27. Water cement ratio is
A. Volume of water to that of cement
B. Weight of water to that of cement
C. Weight of concrete to that of water
D. Both (a) and (b) of the above
Answer : D

28. 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

29. Concrete containing
A. Siliceous aggregates, has higher co-efficient of expansion
B. Igneous aggregates, has intermediate coefficient of expansion
C. Lime stones, has lowest co-efficient of expansion
D. All the above
Answer : D

30. A beam curved in plan is designed for
A. Bending moment and shear
B. Bending moment and torsion
C. Shear and torsion
D. Bending moment, shear and torsion
Answer : D

31. Normally pre-stressing wires are arranged in the
A. Upper part of the beam
B. Lower part of the beam
C. Center
D. Anywhere
Answer : B

32. Shrinkage in concrete can be reduced by using
A. Low water cement ratio
B. Less cement in the concrete
C. Proper concrete mix
D. All the above
Answer : D

33. According to IS: 4561978, the column or the strut is the member whose effective length is greater than
A. The least lateral dimension
B. 2 times the least lateral dimension
C. 3 times the least lateral dimension
D. 4 times the least lateral dimension
Answer : C

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

35. 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

36. Specified compressive strength of concrete is obtained from cube tests at the end of
A. 3 days
B. 7 days
C. 21 days
D. 28 days
Answer : D

37. In pre-stressed concrete
A. Forces of tension and compression change but lever arm remains unchanged
B. Forces of tension and compressions remain unchanged but lever arm changes with the moment
C. Both forces of tension and compression as well as lever arm change
D. Both forces of tension and compression as well as lever arm remain unchanged
Answer : B

38. 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

39. 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

40. 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

41. In counterfort type retaining walls (i) The vertical slab is designed as a continuous slab (ii) The heel slab is designed as a continuous slab (iii) The vertical slab is designed as a cantilever (iv) The heel slab is designed as a cantilever The correct answer is
A. (i) and (ii)
B. (i)and(iv)
C. (ii) and (iii)
D. (iii) and (iv)
Answer : A

42. In a counterfort retaining wall, the main reinforcement is provided on the (i) Bottom face in front counterfort (ii) Inclined face in front counterfort (iii) Bottom face in back counterfort (iv) Inclined face in back counterfort The correct answer is
A. (i) and (ii),
B. (ii) and (iii)
C. (i) and (iv)
D. (iii) and (iv)
Answer : C

43. Select the incorrect statement
A. The loss of pre-stress is more in pre-tensioning system than in posttensioning system.
B. Pre-tensioning system has greater certainty about its durability.
C. For heavy loads and large spans in buildings or bridges, posttensioning system is cheaper than pre-tensioning system
D. None of the above
Answer : D

44. 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

45. 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

46. Assertion A : The load factor for live load is greater than that for dead load. Reason R : The live loads are more uncertain than dead loads. Select your answer based on the coding system given below:
A. Both A and R is true and R is the correct explanation of A
B. Both A and R is true but R is not the correct explanation of A
C. A is true but R is false
D. A is false but R is true
Answer : A

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

48. Increase in the moisture content in concrete
A. Reduces the strength
B. Increases the strength
C. Does not change the strength
D. All of the above
Answer : A

49. Cube strength of controlled concrete to be used for pre-tensioned and post-tensioned work respectively should not be less than
A. 35 MPa and 42 MPa
B. 42 MPa and 35 MPa
C. 42 MPa and 53 MPa
D. 53 MPa and 42 MPa
Answer : B

50. 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