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

1. For a slab supported on its four edges with corners held down and loaded uniformly, the Marcus correction factor to the moments obtained by Grashoff Rankine's theory
A. Is always less than 1
B. Is always greater than 1
C. Can be more than 1
D. Can be less than 1
Answer : A

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

3. 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

4. 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

5. 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

6. The percentage of reinforcement in case of slabs, when high strength deformed bars are used is not less than
A. 0.15
B. 0.12
C. 0.30
D. 1.00
Answer : B

7. 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

8. 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

9. Pick up the incorrect statement from the following. While performing preliminary test on concrete
A. Proportions of the material and water should be the same as to be used at the work site
B. Cement should be mixed by hand in order to maintain uniformity
C. Concrete mix should be stored in air-tight containers
D. Concrete ingredients should be kept at a temperature of 37° ± 2°C
Answer : D

10. The specifications of a cement bag for storage, are
A. Weight 50 kg
B. Height 18 cm
C. Plan area 3000 sq. cm
D. All the above
Answer : D

11. 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

12. The shuttering of a hall measuring 4 m × 5 m, can be removed after
A. 5 days
B. 7 days
C. 10 days
D. 14 days
Answer : B

13. Slump test is done for
A. Clay
B. Sand
C. Lime
D. Concrete
Answer : D

14. For the construction of R.C.C. slabs, columns, beams, walls, etc. the grade of concrete mix used, is
A. 1 : 3 : 6
B. 1 : 1 ½ : 3
C. 1 : 2 : 4
D. 1 : 1 : 2
Answer : C

15. 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

16. 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

17. The maximum value of hoop compression in a dome is given by
A. wR / 4d
B. wR/2d
C. wR/d
D. 2wR/d Where, w = load per unit area of surface of dome R = radius of curvature d = thickness of dome
Answer : B

18. 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

19. 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

20. 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

21. If the average compressive strength is 4000 kg/cm2 and standard deviation is 500, the co-efficient of variation is
A. 10 %
B. 12.5 %
C. 15 %
D. 18.5 %
Answer : B

22. 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

23. For a cantilever of effective depth of 0.5 m, the maximum span to satisfy vertical deflection limit is
A. 3.5 m
B. 4 m
C. 4.5 m
D. 5 m
Answer : A

24. If the depth of moist sand in a cylinder is 15 cm and the depth of the sand when fully inundated with water is 12 cm, the bulking of the moist sand, is
A. 10 %
B. 12 %
C. 15 %
D. 25 %
Answer : D

25. 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

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. In the design of a front counterfort in a counterfort retaining wall, the main reinforcement is provided on (i) Bottom face near counterfort (ii) Top face near counterfort (iii) Bottom face near centre of span (iv) Top face near centre of span The correct answer is
A. Only (i)
B. Only (ii)
C. Both (i) and (iv)
D. Both (ii) and (iii)
Answer : C

28. The centroid of compressive force, from the extreme compression fiber, in limit state design lies at a distance of (Where x_u is the depth of neutral axis at the limit state of collapse)
A. 0.367 x_u
B. 0.416 x_u
C. 0.446 x_u
D. 0.573 x_u
Answer : B

29. 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

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

31. 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

32. 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

33. 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

34. 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

35. If the effective working time is 7 hours and per batch time of concrete is 3 minutes, the output of a concrete mixer of 150 litre capacity, is
A. 15,900 litres
B. 16,900 litres
C. 17,900 litres
D. 18,900 litres
Answer : D

36. Strength of concrete increases with
A. Increase in water-cement ratio
B. Increase in fineness of cement
C. Decrease in curing time
D. Decrease in size of aggregate
Answer : B

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

38. Minimum thickness of load bearing RCC wall should be
A. 50 mm
B. 100 mm
C. 150 mm
D. 200 mm
Answer : B

39. 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

40. 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

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

42. Which of the following statements is incorrect?
A. Minimum cross sectional area of longitudinal reinforcement in a column is 0.8%
B. Spacing of longitudinal bars measured along the periphery of column should not exceed 300 mm
C. Reinforcing bars in a column should not be less than 12 mm in diameter
D. The number of longitudinal bars provided in a circular column should not be less than four
Answer : D

43. 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

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

45. Pick up the incorrect statement from the following:
A. Concrete for which preliminary tests are conducted, is called controlled concrete
B. Bulking of sand depends upon the fineness of grains
C. Concrete mix 1 : 6 : 12, is used for mass concrete in piers
D. All the above
Answer : D

46. 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

47. The relation between modulus of rupture f_cr, splitting strength f_cs and direct tensile strength f_cl is given by
A. f_cr - f_cs = f_cl
B. f_cr > f_cs > f_cl
C. f_cr < f_cs < f_cl
D. f_cs > f_cr > f_cl
Answer : B

48. Horizontal construction joints in concrete walls are generally provided at
A. Soffit level
B. Window sill level
C. Floor level
D. All the above
Answer : D

49. 1% of voids in a concrete mix would reduce its strength by about
A. 5 %
B. 10 %
C. 15 %
D. 20 %
Answer : A

50. Pick up the correct statement from the following:
A. Lime in excess, causes the cement to expand and disintegrate
B. Silica in excess, causes the cement to set slowly
C. Alumina in excess, reduces the strength of the cement
D. All the above
Answer : D