Concrete Technology and Design 1000+ MCQ with answer for JEE Main

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

2. Efflorescence in cement is caused due to an excess of
A. Alumina
B. Iron oxide
C. Silica
D. Alkalis
Answer : D

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

4. Addition of pozzolana to cement causes
A. Reduction in permeability
B. Loss of heat of hydration
C. Reduction in bleeding
D. All the above
Answer : D

5. According to IS: 4561978, minimum slenderness ratio for a short column is
A. Less than 12
B. Less than 18
C. Between 18 and 24
D. More than 24
Answer : A

6. A higher modular ratio shows
A. Higher compressive strength of concrete
B. Lower compressive strength of concrete
C. Higher tensile strength of steel
D. Lower tensile strength of steel
Answer : B

7. The load factors for live load and dead load are taken respectively as
A. 1.5 and 2.2
B. 2.2 and 1.5
C. 1.5 and 1.5
D. 2.2 and 2.2
Answer : B

8. The slab is designed as one way if the ratio of long span to short span is
A. Less than 1
B. Between 1 and 1.5
C. Between 1.5 and 2
D. Greater than 2
Answer : D

9. 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

10. 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

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

12. 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

13. Pick up the incorrect statement from the following:
A. Space between the exterior walls of a warehouse and bag piles should be 30 cm
B. Cement bags should preferably be piled on wooden planks
C. Width and height of the pile should not exceed 3 m and 2.70 m respectively
D. None of these
Answer : D

14. To hydrate 500kg of cement full water needed, is
A. 100 kg
B. 110 kg
C. 120 kg
D. 130 kg
Answer : D

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

16. 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

17. For ensuring quality of concrete, use
A. Single sized aggregates
B. Two sized aggregate
C. Graded aggregates
D. Coarse aggregates
Answer : C

18. 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

19. 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

20. Pick up the correct statement from the following:
A. Cement should be mixed for at least one minute
B. 10% of water is placed in the rotating drum before adding dry material
C. 10% of water is added after placing the other ingredients in the drum
D. All the above
Answer : D

21. 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

22. According to Water-Cement Ratio Law, the strength of workable plastic concrete
A. Depends upon the amount of water used in the mix
B. Does not depend upon the quality of cement mixed with aggregates
C. Does not depend upon the quantity of cement mixed with aggregates
D. All the above
Answer : D

23. Which of the following statements is incorrect?
A. Higher Vee-Bee time shows lower workability
B. Higher slump shows higher workability
C. Higher compacting factor shows higher workability
D. None of the above
Answer : D

24. The final operation of finishing floors, is known as
A. Screeding
B. Floating
C. Trowelling
D. Finishing
Answer : C

25. 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

26. Pick up the incorrect statement from the following:
A. The degree of grinding of cement, is called fineness
B. The process of changing cement paste into hard mass, is known as setting of cement
C. The phenomenon by virtue of which cement does not allow transmission of sound, is known as soundness of cement
D. The heat generated during chemical reaction of cement with water, is known as heat of hydration
Answer : C

27. Saw dust can be rendered chemically inert by boiling it in water containing
A. Ferrous sulphate
B. Potassium chloride
C. Ammonia
D. Nitric acid
Answer : A

28. 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

29. The maximum thickness of concrete floor of a cement warehouse, is
A. 10 cm
B. 15 cm
C. 20 cm
D. 25 cm
Answer : D

30. Vicat's apparatus is used for
A. Fineness test
B. Consistency test
C. Setting time test
D. Soundness test
Answer : B

31. 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

32. Maximum quantity of water needed per 50 kg of cement for M 15 grade of concrete is
A. 28 liters
B. 30 liters
C. 32 liters
D. 34 liters
Answer : C

33. 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

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

35. Hardening of cement occurs at
A. Rapid rate during the first few days and afterwards it continues to increase at a decreased rate
B. Slow rate during the first few days and afterwards it continues to increase at a rapid rate
C. Uniform rate throughout its age
D. None of these
Answer : D

36. 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

37. The grade of concrete M 150 means that compressive strength of a 15 cm cube after 28 days, is
A. 100 kg/cm2
B. 150 kg/cm2
C. 200 kg/cm2
D. 250 kg/cm2
Answer : B

38. C.R.R.I. charts are used to obtain a relationship between strength of concrete and
A. Water cement ratio
B. Workability
C. Grading of aggregate
D. Fineness modulus
Answer : A

39. To ensure constant moisture content in aggregates
A. Area of each aggregate pile should be large
B. Height of each aggregate pile should not exceed 1.50 m
C. Aggregate pile should be left for 24 hours before aggregates are used
D. All the above
Answer : D

40. 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

41. 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

42. 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

43. 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

44. 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

45. After casting, an ordinary cement concrete on drying
A. Expands
B. Mix
C. Shrinks
D. None of these
Answer : C

46. Concrete gains strength due to
A. Chemical reaction of cement with sand and coarse aggregates
B. Evaporation of water from concrete
C. Hydration of cement
D. All the above
Answer : C

47. 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

48. 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

49. The 28 days cube strength of mass concrete using aggregates of maximum size 5 cm for gravity dams should be
A. Between 150 to 300 kg/cm²
B. Between 350 to 600 kg/cm²
C. Between 150 to 500 kg/cm²
D. Below 200 kg/cm²
Answer : D

50. 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