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

1. For the construction of cement concrete dams, the maximum permissible size of the aggregates, is
A. 40 mm
B. 50 mm
C. 60 mm
D. 70 mm
Answer : A

2. 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

3. 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

4. For preparing ordinary concrete, the quantity of water used, is
A. 5% by weight of aggregates plus 20% of weight of cement
B. 10% by weight of aggregates plus 10% of weight of cement
C. 5% by weight of aggregates plus 30% of weight of cement
D. 30% by weight of aggregates plus 10% of weight of cement
Answer : C

5. 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

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

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

8. Minimum pitch of transverse reinforcement in a column is
A. The least lateral dimension of the member
B. Sixteen times the smallest diameter of longitudinal reinforcement bar to be tied
C. Forty-eight times the diameter of transverse reinforcement
D. Lesser of the above three values
Answer : D

9. The impurity of mixing water which affects the setting time and strength of concrete, is
A. Sodium sulphates
B. Sodium chlorides
C. Sodium carbonates and bicarbonates
D. Calcium bicarbonates
Answer : C

10. For road pavements, the cement generally used, is
A. Ordinary Portland cement
B. Rapid hardening cement
C. Low heat cement
D. Blast furnace slag cement
Answer : B

11. Addition of pozzolana to ordinary port land cement, causes
A. Decrease in early strength
B. Reduction in chemical action with sulphates
C. Increase in shrinkage
D. All the above
Answer : D

12. A concrete using an air entrained cement
A. Has strength less than 10% to 15%
B. Has more resistance to weathering
C. Is more plastic and workable
D. Is free from segregation and bleeding
Answer : C

13. Bulking of sand is maximum if moisture content is about
A. 2 %
B. 4 %
C. 6 %
D. 10 %
Answer : B

14. 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

15. If the engineer-in-charge approves, the 10 cm cubes may be used for the work test of concrete provided maximum nominal size of aggregate, does not exceed
A. 10 cm
B. 15 cm
C. 20 cm
D. 25 cm
Answer : C

16. On a grading curve, the gap grading is represented by
A. A horizontal line
B. A vertical line
C. N.W. inclined line
D. N.E. inclined line
Answer : A

17. 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

18. 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

19. 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

20. 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

21. Due to circumferential action of the spiral in a spirally reinforced column
A. Capacity of column is decreased
B. Ductility of column reduces
C. Capacity of column is decreased but ductility of column increases
D. Both the capacity of column and ductility of column increase
Answer : D

22. 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

23. 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

24. Grading of sand causes great variation in
A. Workability of concrete
B. Strength of concrete
C. Durability of concrete
D. All the above
Answer : D

25. Curing
A. Reduces the shrinkage of concrete
B. Preserves the properties of concrete
C. Prevents the loss of water by evaporation
D. All of the above
Answer : D

26. Separation of coarse aggregates from mortar during transportation, is known
A. Bleeding
B. Creeping
C. Segregation
D. Shrinkage
Answer : C

27. An ordinary Portland cement when tested for its fineness, should not leave any residue on I.S. sieve No. 9, more than
A. 5 %
B. 10 %
C. 15 %
D. 20 %
Answer : B

28. Workability of concrete is directly proportional to
A. Aggregate cement ratio
B. Time of transit
C. Grading of the aggregate
D. All of above
Answer : C

29. As compared to ordinary Portland cement, use of pozzolana cement
A. Reduces workability
B. Increases bleeding
C. Increases shrinkage
D. Increases strength
Answer : C

30. 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

31. 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

32. 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

33. Pick up the incorrect statement applicable to the field test of good cement.
A. When one thrusts one's hand into a bag of cement, one should feel warm
B. The colour of the cement is bluish
C. By rubbing cement in between fingers, one should feed rough
D. All the above
Answer : D

34. The effect of creep on modular ratio is
A. To decrease it
B. To increase it
C. Either to decrease or to increase it
D. To keep it unchanged
Answer : B

35. 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

36. Pick up the correct statement from the following:
A. Continuous grading is not necessary for obtaining a minimum of air voids
B. The omission of a certain size of aggregate is shown by a straight horizontal line on the grading curve
C. The omission of a certain size of aggregate in concrete increases the workability but also increases the liability to segregation
D. All the above
Answer : D

37. 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

38. For quality control of Portland cement, the test essentially done is
A. Setting time
B. Tensile strength
C. Consistency
D. All the above
Answer : D

39. 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

40. Finer grinding of cement
A. Affects only the early development of strength
B. Affects only the ultimate strength
C. Both (A) and (B)
D. Does not affect the strength
Answer : A

41. 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

42. The strength and quality of concrete, depend upon:
A. Grading of aggregates
B. Surface area of aggregates
C. Shape of aggregates
D. All the above
Answer : D

43. For a simply supported beam of span 15 m, the minimum effective depth to satisfy the vertical deflection limits should be
A. 600 mm
B. 750 mm
C. 900 mm
D. More than 1 m
Answer : B

44. 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

45. 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

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

47. 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

48. 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

49. The process of hardening the concrete by keeping its surface moist is known
A. Placing
B. Wetting
C. Curing
D. Compacting
Answer : C

50. 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