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

1. For construction of structures in sea water, the cement generally preferred to, is
A. Portland-pozzolana cement
B. Quick setting cement
C. Low heat Portland cement
D. Rapid hardening cement
Answer : A

2. 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

3. 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

4. Ultimate strength of cold drawn high steel wires
A. Increases with increase in diameter of bar
B. Decreases with increase in diameter of bar
C. Does not depend on diameter of bar
D. None of the above
Answer : B

5. While compacting the concrete by a mechanical vibrator, the slump should not exceed
A. 2.5 cm
B. 5.0 cm
C. 7.5 cm
D. 10 cm
Answer : B

6. 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

7. Joints in concrete structures, are provided
A. To reduce the tensile stresses likely to be developed due to evaporation of water
B. To minimise the change in the dimensions of the slab
C. To minimise the necessary cracking
D. All the above
Answer : D

8. 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

9. 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

10. Proper proportioning of concrete, ensures
A. Desired strength and workability
B. Desired durability
C. Water tightness of the structure
D. All the above
Answer : D

11. The diameter of the Vicat plunger is 10 mm and its length varies from
A. 20 mm to 30 mm
B. 30 mm to 40 mm
C. 40 mm to 50 mm
D. 50 mm to 60 mm
Answer : C

12. The type of aggregates of same nominal size, which contain less voids when compacted, are
A. Rounded spherical
B. Irregular
C. Flaky
D. None of these
Answer : A

13. 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

14. If P, Y and Z are the weights of cement, fine aggregates and coarse aggregates respectively and W/C is the water cement ratio, the minimum quantity of water to be added to first batch, is obtained by the equation
A. 0.1P + 0.3Y + 0.1Z = W/C × P
B. 0.3P + 0.1Y + 0.01Z = W/C × P
C. 0.4P + 0.2Y + 0.01Z = W/C × P
D. 0.5P + 0.3Y + 0.01Z = W/C × P
Answer : B

15. For concreting of heavily reinforced sections without vibration, the workability of concrete expressed as compacting factor should be
A. 0.75 - 0.80
B. 0.80 - 0.85
C. 0.85 - 0.92
D. Above 0.92
Answer : D

16. 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

17. 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

18. For the construction of thin R.C.C. structures, the type of cement to be avoided, is
A. Ordinary Portland cement
B. Rapid hardening cement
C. Low heat cement
D. Blast furnace slag cement
Answer : D

19. 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

20. Le-Chatelier's apparatus is used for testing
A. Soundness of cement
B. Hardness of cement
C. Strength of cement
D. Durability of cement
Answer : A

21. 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

22. 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

23. 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

24. Particles of 0.002 mm size are that of
A. Clay
B. Sand
C. Gravel
D. None of these
Answer : A

25. 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

26. For a longitudinal reinforcing bar in a column, the minimum cover shall neither be less than the diameter of bar nor less than
A. 15 mm
B. 25 mm
C. 30 mm
D. 40 mm
Answer : D

27. Pick up the correct statement from the following:
A. The concrete gains strength due to hydration of cement
B. The concrete does not set at freezing point
C. The strength of concrete increases with its age
D. All the above
Answer : D

28. If the various concrete ingredients i.e. cement, sand and aggregates are in the ratio of 1:3:6, the grade of concrete, is
A. M 100
B. M 150
C. M 200
D. M 250
Answer : A

29. Pick up the correct statement from the following:
A. A highly absorptive aggregate reduces the workability of concrete considerably
B. The specific gravity of aggregate is important for the determination of the moisture content
C. The absorption and porosity of an aggregate influence the property of the concrete
D. All the above
Answer : D

30. Pick up the correct statement from the following:
A. High percentage of C₃S and low percentage of C₂S cause rapid hardening
B. High percentage of C₃S and low percentage of C₂S make the cement less resistive to chemical attack
C. Low percentage of C₃S and high percentage of C₂S contribute to slow hardening
D. All the above
Answer : D

31. 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

32. 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

33. In T-shaped R C. retaining walls, the main reinforcement in the stem is provided on
A. The front face in one direction
B. The front face in both directions
C. The inner face in one direction
D. The inner face in both directions
Answer : C

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

35. Pozzolanic properties exist in
A. Shales
B. Fly ash
C. Pumicite
D. All the above
Answer : D

36. 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

37. Workability of concrete for a given water content is good if the aggregates, are
A. Rounded aggregate
B. Irregular aggregate
C. Angular aggregate
D. Flaky aggregates
Answer : A

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

39. 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

40. 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

41. An aggregate is said to be flaky if its least dimension is less than
A. 1/5th of mean dimension
B. 2/5th of mean dimension
C. 3/5th of mean dimension
D. 4/5th of mean dimension
Answer : C

42. In the method of voids for determination of the quantity of cement paste, it is assumed that
A. Voids in coarse aggregates are filled by fine aggregates
B. Voids in fine aggregates are filled by the cement paste
C. Volume of fine aggregates is equal to total voids in coarse aggregates plus 10% extra
D. All the above
Answer : D

43. For concreting tunnel linings, transportation of concrete is done by
A. Pans
B. Wheel borrows
C. Containers
D. Pumps
Answer : D

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

45. The critical section for finding maximum bending moment for footing under masonry wall is located
A. At the middle of the wall
B. At the edge of the wall
C. Halfway between the middle and edge of the wall
D. At a distance equal to effective depth of footing from the edge of the wall
Answer : C

46. 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

47. M10 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 : A

48. 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

49. 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

50. 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