# 300+ Design of Reinforced Concrete Structures MCQs and Answers

## Design of Reinforced Concrete Structures Multiple Choice Questions Quiz

1. The load stress of a section can be reduced by
A. Decreasing the lever arm
B. Increasing the total perimeter of bars
C. Replacing larger bars by greater number of small bars
D. Replacing smaller bars by greater number of greater bars

Answer: C Replacing larger bars by greater number of small bars

2. The diameter of the column head support a flat slab, is generally kept
A. 0.25 times the span length
B. 0.25 times the diameter of the column
C. 4.0 cm larger than the diameter of the column
D. 5.0 cm larger than the diameter of the column

Answer: B 0.25 times the diameter of the column

3. An R.C.C. beam of 6 m span is 30 cm wide and has a lever arm of 55 cm. If it carries a U.D.L. of 12 t per m and allowable shear stress is 5 kg/cm2, the beam
A. Is safe in shear
B. Is safe with stirrups
C. Is safe with stirrups and inclined bars
D. Needs revision of section

Answer: B Is safe with stirrups

4. According to I.S. : 456, slabs which span in two directions with corners held down, are assumed to be divided in each direction into middle strips and edge strips such that the width of the middle strip, is
A. Half of the width of the slab
B. Two-third of the width of the slab
C. Three-fourth of the width of the slab
D. Four-fifth of the width of the slab

Answer: C Three-fourth of the width of the slab

5. If ‘W’ is the uniformly distributed load on a circular slab of radius ‘R‘fixed at tsends, the maximum positive radial moment at its centre, is
A. 3WR²/16
B. 2WR²/16
C. WR²/16
D. None of these

6. The maximum ratio of span to depth of a slab simply supported and
A. 35
B. 25
C. 30
D. 20

7. Pick up the correct statement from the following
A. Lateral reinforcement in R.C.C. columns is provided to prevent the longitudinal reinforcement from buckling
B. Lateral reinforcement prevents the shearing of concrete on diagonal plane
C. Lateral reinforcement stops breaking away of concrete cover, due to buckling
D. All the above

8. In case the factor of safety against sliding is less than 1.5, a portion of slab is constructed downwards at the end of the heel slab, which is known as
A. A key
B. A cut-off wall
C. A rib
D. All the above

9. Lapped splices in tensile reinforcement are generally not used for bars of size larger than
A. 18 mmdiameter
B. 24 mmdiameter
C. 30 mmdiameter
D. 36 mmdiameter

10. Minimum spacing between horizontal parallel reinforcement of the same size should not be less than
A. Onediameter
B. 2.5 diameters
C. 3 diameters
D. 3.5 diameters

11. For a ribbed slab
A. Clear spacing between ribs shall not be greater than 4.5 cm
B. Width of the rib shall not be less than 7.5 cm
C. Overall depth of the slab shall not exceed four times the breadth of the rib
D. All the above

12. A very comfortable type of stairs is
A. Straight
B. Dog legged
C. Geometrical
D. Open newel

13. Columns may be made of plain concrete if their unsupported lengths do not exceed their least lateral dimension
A. Two times
B. Three times
C. Four times
D. Five times

14. The width of the flange of a L-beam, should be less than
A. One-sixth of the effective span
B. Breadth of therib + four times thickness of the slab
C. Breadth of the rib + half clear distance betweenribs
D. Least of theabove

15. To ensure uniform pressure distribution, the thickness of the foundation, is
A. Kept uniform throughout
B. Increased gradually towards the edge
C. Decreased gradually towards the edge
D. Kept zero at theedge

16. The maximum permissible size of aggregates to be used in casting the ribs of a slab, is
A. 5 mm
B. 7.5 mm
C. 10 mm
D. 15 mm

17. Pick up the incorrect statement from the following: Tensile reinforcement bars of a rectangular beam
A. Are curtailed if not required to resist the bendingmoment
B. Are bent up at suitable places to serve as shearreinforcement
C. Are bent down at suitable places to serve asshear reinforcement
D. Are maintained at bottom to provide at least local bond stress

Answer: C Are bent down at suitable places to serve asshear reinforcement

18. Steel bars are generally connected together to get greater length than the standard length by providing
A. Straight bar splice
B. Hooked splice
C. Dowel splice
D. All the above

19. Top bars are extended to the projecting parts of the combined footing of two columns Ldistance apart for a distance of
A. 0.1 L from the outer edge of column
B. 0.1 L from the centre edge ofcolumn
C. Half the distance of projection
D. One-fourth the distance of projection

Answer: B 0.1 L from the centre edge ofcolumn

20. For M 150 grade concrete (1:2:4) the moment of resistance factor is
A. (A) 0.87
B. (B) 8.50
C. (C) 7.50
D. (D) 5.80

21. The minimum thickness of a flat slab is taken
A. L/32 for end panels without drops
B. L/36 for end panels without drops
C. L/36 for interior panels without drop
D. All the above

22. The neutral axis of a T-beam exists
A. Within the flange
B. At the bottom edge of the slab
C. Below the slab
D. All the above

23. The design of heel slab of a retaining wall is based on the maximum bending moment due to:
A. Its own weight
B. Weight of the soil above it
C. Load of the surcharge, if any
D. All the above

24. A pre-cast pile generally used, is
A. Circular
B. Square
C. Octagonal
D. Square with corners chamfered

Answer: D Square with corners chamfered

25. The spacing of transverse reinforcement of column is decided by the following consideration.
A. The least lateral dimension of the column
B. Sixteen times the diameter of the smallest longitudinal reinforcing rods in the column
C. Forty-eight times the diameter of transverse reinforcement
D. All the above

26. The self-weight of the footing, is
A. Not considered for calculating the upward pressure on footing
B. Also considered for calculating the upward pressure on footing
C. Not considered for calculating the area of the footing
D. Both (b) and (c)

Answer: A Not considered for calculating the upward pressure on footing

27. Pick up the incorrect statement from the following:
A. In the stem of a retaining wall, reinforcement is provided near the earth side
B. In the toe slab of a retaining wall, reinforcement is provided at the bottom of the slab
C. In the heel slab of a retaining wall, reinforcement is provided at the top of the slab
D. None of these

28. The transverse reinforcements provided at right angles to the main reinforcement
B. Resist the temperature stresses
C. Resist the shrinkage stress
D. All the above

29. The pitch of the main bars in a simply supported slab, should not exceed its effective depth by
A. Three times
B. Four times
C. Five times
D. Six times

30. High strength concrete is used in pre-stressed member
A. To overcome high bearing stresses developed at theends
B. To overcome bursting stresses at the ends
C. To provide high bond stresses
D. All the above

31. Enlarged head of a supporting column of a flat slab is technically known as
A. Supporting end of the column
B. Top of the column
C. Capital
D. Drop panel

32. Thickened part of a flat slab over its supporting column, is technically known as
A. Drop panel
B. Capital
D. None of these

33. Side face reinforcement shall be provided in the beam when depth of the web in a beam exceeds
A. 50 cm
B. 75 cm
C. 100 cm
D. 120 cm

34. The minimum head room over a stair must be
A. 200 cm
B. 205 cm
C. 210 cm
D. 230 cm

35. The Young’s modulus of elasticity of steel, is
A. 150 KN/mm2
B. 200 KN/mm2
C. 250 KN/mm2
D. 275 KN/mm2

36. Spacing of stirrups in a rectangular beam, is
A. Kept constant throughout the length
B. Decreased towards the centre of the beam
C. Increased at the ends
D. Increased at the centre of the beam

Answer: D Increased at the centre of the beam

37. As per IS : 456, the reinforcement in a column should not be less than
A. 0.5% and not more than 5% of cross
B. 0.6% and not more than 6% of cross
C. 0.7% and not more than 7% of cross
D. 0.8% and not more than 8% of cross

Answer: D 0.8% and not more than 8% of cross

38. The allowable tensile stress in mild steel stirrups, reinforced cement concrete, is
A. 1400 kg/cm2
B. 190 kg/cm2
C. 260 kg/cm2
D. 230 kg/cm2

39. Bottom bars under the columns are extended into the interior of the footing slab to a distance greater than
A. 42 diameters from the centre of the column
B. 42 diameters from the inner edge of the column
C. 42 diameters from the outer edge of the column
D. 24 diameters from the centre of the column

Answer: C 42 diameters from the outer edge of the column

40. The advantage of reinforced concrete, is due to
A. Monolithic character
B. Fire-resisting and durability
C. Economy because of less maintenance cost
D. All the above

41. The thickness of the topping of a ribbed slab, varies between
A. 3 cm to 5 cm
B. 5 cm to 8 cm
C. 8 cm to 10 cm
D. 12 cm to 15 cm

Answer: B 5 cm to 8 cm

42. The maximum ratio of span to depth of a slab simply supported and spanning in two directions, is
A. 25
B. 30
C. 35
D. 40

43. If the loading on a pre-stressed rectangular beam, is uniformly distributed, the tendon to be provided should be.
A. Straight below centroidal axis
B. Parabolic with convexity downward
C. Parabolic with convexity upward
D. Straight above centroidal axis

Answer: B Parabolic with convexity downward

44. For normal cases, stiffness of a simply supported beam is satisfied if the ratio of its span to its overall depth does not exceed
A. 10
B. 15
C. 20
D. 25

45. If depth of slab is 10 cm, width of web 30 cm, depth of web 50 cm, centre to centre distance of beams 3 m, effective span of beams 6 m, the effective flange width of the beam, is
A. 200 cm
B. 300 cm
C. 150 cm
D. 100 cm

46. The steel generally used in R.C.C. work, is
A. Stainless
B. Mild steel
C. High carbon steel
D. High tensionsteel

47. A part of the slab may be considered as the flange of the T-beam if
A. Flange has adequate reinforcement transverse to beam
B. It is built integrally with the beam
C. It is effectively bonded together with the beam
D. All the above

48. By over-reinforcing a beam, the moment of resistance can be increased not more than
A. 10 %
B. 15 %
C. 20 %
D. 25 %

49. According to I.S.: 456, 1978 the thickness of reinforced concrete footing on piles at its edges, is kept less than
A. 5 cm
B. 10 cm
C. 15 cm
D. 20 cm

50. The live load to be considered for an accessible roof, is
A. Nil
B. 75 kg/m3
C. 150 kg/m2
D. 200 kg/cm2

51. On an absolutely rigid foundation base, the pressure will
A. Be more at the edges of the foundation
B. Be uniform
C. Not be uniform
D. Be zero at the centre of the foundation

52. The diameter of transverse reinforcement of columns should be equal to one-fourth of the diameter of the main steel rods but not less than
A. 4 mm
B. 5 mm
C. 6 mm
D. 7 mm

53. For a continuous floor slab supported on beams, the ratio of end span length and intermediate span length, is
A. 0.6
B. 0.7
C. 0.8
D. 0.9

54. In a singly reinforced beam
A. Compression is borne entirely by concrete
B. Steel possesses initial stresses when embedded in concrete
C. Plane sections transverse to the centre line of the beam before bending remain plane after bending
D. Elastic moduli for concrete and steel have different values within the limits of deformation of the beam

Answer: C Plane sections transverse to the centre line of the beam before bending remain plane after bending

55. The ratio of the breadth to effective depth of a beam is kept
A. 0.25
B. 0.50
C. 0.70
D. 0.75

56. A T-beam behaves as a rectangular beam of a width equal to its flange if its neutral axis
A. Remains within the flange
B. Remains below the slab
C. Coincides the geometrical centre of the beam
D. None of these

Answer: A Remains within the flange

57. The width of the rib of a T-beam, is generally kept between
A. 1/7 to 1/3 of rib depth
B. 1/3 to 1/2 of rib depth
C. 1/2 to 3/4 of rib depth
D. 1/3 to 2/3 of rib depth

Answer: D 1/3 to 2/3 of rib depth

58. For the design of a simply supported T-beam the ratio of the effective span to the overall depth of the beam is limited to
A. 10
B. 15
C. 20
D. 25

59. If the depth of actual neutral axis of a doubly reinforced beam
A. Is greater than the depth of critical neutral axis, the concrete attains its maximum stress earlier
B. Is less than the depth of critical neutral axis, the steel in the tensile zone attains its maximum stress earlier
C. Is equal to the depth of critical neutral axis; the concrete and steel attain their maximum stresses simultaneously
D. All the above

60. The maximum diameter of a bar used in a ribbed slab, is
A. 12 mm
B. 6 mm
C. 20 mm
D. 22 mm

61. If the diameter of the main reinforcement in a slab is 16 mm, the concrete cover to main bars is
A. 10 mm
B. 12 mm
C. 14 mm
D. 16 mm

62. Minimum spacing between horizontal parallel reinforcement of different sizes, should not be less than
A. One diameter of thinner bar
B. One diameter of thicker bar
C. Twice the diameter of thinner bar
D. None of these

Answer: B One diameter of thicker bar

63. The diameter of main bars in R.C.C. columns, shall not be less than
A. 6 mm
B. 8 mm
C. 10 mm
D. 12 mm

64. Dimensions of a beam need be changed if the shear stress is more than
A. 10 kg/cm2
B. 15 kg/cm2
C. 20 kg/cm2
D. 25 kg/cm2

65. The effective span of a simply supported slab, is
A. Distance between the centres of thebearings
B. Clear distance between the inner faces of the walls plus twice the thickness of the wall
C. Clear span plus effective depth of the slab
D. None of these

Answer: B Clear distance between the inner faces of the walls plus twice the thickness of the wall

66. The maximum ratio of span to depth of a cantilever slab, is
A. 8
B. 10
C. 12
D. 16

67. The horizontal portion of a step in a stairs case, is known as
A. Rise
B. Flight
C. Winder

68. An R.C.C. roof slab is designed as a two way slab if
A. It supports live loads in both directions
B. The ratio of spans in two directions is less than 2
C. The slab is continuous over two supports
D. The slab is discontinuous at edges

Answer: B The ratio of spans in two directions is less than 2

69. In a combined footing for two columns carrying unequal loads, the maximum hogging bending moment occurs at
C. A point of the maximum shear force
D. A point of zero shear force

Answer: D A point of zero shear force

70. If the effective length of a 32 cm diameter R.C.C. column is 4.40 m, its slenderness ratio, is
A. 40
B. 45
C. 50
D. 55

71. The radius of a bar bend to form a hook, should not be less than
A. Twice thediameter
B. Thrice thediameter
C. Four times the diameter
D. Five times the diameter

72. A simply supported beam 6 m long and of effective depth 50 cm, carries a uniformly distributed load 2400 kg/m including its self weight. If the lever arm factor is 0.85 and permissible tensile stress of steel is 1400 kg/cm2, the area of steel required, is
A. 14 cm2
B. 15 cm2
C. 16 cm2
D. 17 cm2

73. The amount of reinforcement for main bars in a slab, is based upon
A. Minimum bendingmoment
B. Maximumbendingmoment
C. Maximum shear force
D. Minimum shearforce

74. The diameter of longitudinal bars of a column should never be less than
A. 6 mm
B. 8 mm
C. 10 mm
D. 12 mm

75. Steel beam theory is used for
A. Design of simple steel beams
B. Steel beams encased in concrete
C. Doubly reinforced beams ignoring compressive stress inconcrete
D. Beams if shear exceeds 4 times allowable shear stress

Answer: C Doubly reinforced beams ignoring compressive stress inconcrete

76. In a singly reinforced beam, the effective depth is measured from its compression edge to
A. Tensile edge
B. Tensile reinforcement
C. Neutral axis of the beam
D. Longitudinal centralaxis

77. The minimum number of main steel bars provided in R.C.C.
A. Rectangular columns is 4
B. Circular columns is 6
C. Octagonal columns is 8
D. All the above

78. If the size of a column is reduced above the floor, the main bars of the columns, are
A. Continued up
B. Bent inward at the floor level
C. Stopped just below the floor level and separate lap barsprovided
D. All the above

79. In a singly reinforced beam, if the permissible stress in concrete reaches earlier than that in steel, the beam section is called
A. Under-reinforced section
B. Over reinforced section
C. Economic section
D. Critical section

80. Distribution of shear intensity over a rectangular section of a beam, follows:
A. A circular curve
B. A straight line
C. A parabolic curve
D. An ellipticalcurve

81. Distribution reinforcement in a simply supported slab, is provided to distribute
B. Temperature stress
C. Shrinkage stress
D. All the above

82. Design of R.C.C. simply supported beams carrying U.D.L. is based on the resultant B.M. at
A. Supports
B. Mid span
C. Every section
D. Quarter span

83. An R.C.C. column is treated as long if its slenderness ratio is greater than
A. 30
B. 35
C. 40
D. 50

84. If the diameter of longitudinal bars of a square column is 16 mm, the diameter of lateral ties should not be less than
A. 4 mm
B. 5 mm
C. 6 mm
D. 8 mm

85. The weight of a foundation is assumed as
A. 5% of wallweight
B. 7% of wallweight
C. 10% of wall weight
D. 12% of wall weight

Answer: C 10% of wall weight

86. For M 15 mix concrete, according to I.S. specifications, local bond stress, is
A. 5 kg/cm2
B. 10 kg/cm2
C. 15 kg/cm2
D. 20 kg/cm2

87. As per I.S. 456 – 1978, the pH value of water shall be
A. Less than 6
B. Equal to 6
C. Not less than 6
D. Equal to 7

Answer: C Not less than 6

88. If diameter of a reinforcement bar is d, the anchorage value of the hook is
A. 4d
B. 8d
C. 12d
D. 16d

89. If the sides of a slab simply supported on edges and spanning in two directions are equal, the maximum bending moment is multiplied by
A. 0.2
B. 0.3
C. 0.4
D. 0.5

90. The maximum shear stress (qmax) in a rectangular beam is
A. 1.25 times the average
B. 1.50 times the average
C. 1.75 times the average
D. 2.0 times theaverage

Answer: B 1.50 times the average

91. Side face reinforcement shall be provided in the beam when depth of the web in a beam exceeds Drop panel
A. 50 cm
B. 75 cm
C. 100 cm
D. 120 cm

92. In a slab, the pitch of the main reinforcement should not exceed its effective depth
A. Three times
B. Four times
C. Five times
D. Two times

93. The maximum ratio of span to depth of a slab simply supported and spanning in two directions, is
A. 25
B. 30
C. 35
D. 40

94. By over-reinforcing a beam, the moment of resistance can be increased not more than
A. 10 %
B. 15 %
C. 20 %
D. 25 %

95. For normal cases, stiffness of a simply supported beam is satisfied if the ratio of its span to its overall depth does not exceed
A. 10
B. 15
C. 20
D. 25

96. A T-beam behaves as a rectangular beam of a width equal to its flange if its neutral axis
A. 1/7 to 1/3 of rib depth
B. 1/3 to 1/2 of rib depth
C. 1/2 to 3/4 of rib depth
D. 1/3 to 2/3 of rib depth

Answer: D 1/3 to 2/3 of rib depth

97. A ribbed slab is provided for
A. A plain ceiling
B. Thermal insulation
C. Acousticinsulation
D. All the above

98. A column is regarded as long column if the ratio of its effective length and lateral dimension, exceeds
A. 10
B. 15
C. 20
D. 25

99. The length of lap in tension reinforcement should not be less than the bar diameter × (actual tension / four times the permissible average bond stress) if it is more than
A. 18 bardiameters
B. 24 bardiameters
C. 30 bardiameters
D. 36 bar diameters

100. The weight of reinforced concrete, is generally taken as
A. 2200 kg/m3
B. 2300 kg/m3
C. 2400 kg/m3
D. 2500 kg/m3

101. In a beam the local bond stress Sb, is equal to
A. Shear force/(Leaver arm × Total perimeter of reinforcement)
B. Total perimeter of reinforcement/(Leaver arm × Shear force)
C. Leaver arm/(Shear force × Total perimeter of reinforcement)
D. Leaver arm/(Bending moment × Total perimeter ofreinforcement)

Answer: A Shear force/(Leaver arm × Total perimeter of reinforcement)

102. A continuous beam shall be deemed to be a deep beam if the ratio of effective span to overall depth, is
A. 2.5
B. 2.0
C. Less than 2
D. Less than 2.5

103. If the length of a wall on either side of a lintel opening is at least half of its effective span L, the load W carried by the lintel is equivalent to the weight of brickwork contained in an equilateral triangle, producing a maximum bending moment
A. WL/2
B. WL/4
C. WL/6
D. WL/8

104. The section of a reinforced beam where most distant concrete fibre in compression and tension in steel attains permissible stresses simultaneously, is called
A. Balanced section
B. Economic section
C. Critical section
D. All the above

105. The vertical portion of a step in a stairs case, is known as
A. Rise
B. Flight
C. Winder

106. For stairs spanning horizontally, the minimum waist provided is
A. 4 cm
B. 6 cm
C. 8 cm
D. 12 cm

107. The advantage of a concrete pile over a timber pile, is
A. No decay due to termites
B. No restriction on length
C. Higher bearingcapacity
D. All the above

108. If the average bending stress is 6 kg/cm2 for M 150 grade concrete, the length of embedment of a bar of diameter d according to I.S. 456 specifications, is
A. 28 d
B. 38 d
C. 48 d
D. 58 d

109. For M20 grade of concrete, the maximum shear stress shall not exceed
A. 1.6 N/mm2
B. 1.9 N/mm2
C. 2.8 N/mm2
D. 2.2 N/mm2

110. The number of treads in a flight is equal to
A. Risers in the flight
B. Risers plus one
C. Risers minus one
D. None of these

111. The bond strength between steel and concrete is due to
A. friction
D. None of these

112. In a public building width of stair should be at least
A. 1000 mm
B. 1200 mm
C. 1500 mm
D. 1800 mm

113. When minimum eccentricity in columns does not exceed 0.05 times the lateral dimension, the axial load carrying capacity is reduced by
A. 8%
B. 11%
C. 14%
D. 20%

114. The maximum percentage of moment redistribution allowed in RCC beams is
A. 10%
B. 20%
C. 30%
D. 40%

115. Minimum grade of concrete for moderate exposure with normal weight aggregates is
A. M 15
B. M 20
C. M 25
D. M 35

116. Minimum grade of concrete for moderate exposure with normal weight aggregates is
A. M 15
B. M 20
C. M 25
D. M 35

117. The minimum reinforcement using mild steel in slab should not be less than
A. 0.10%
B. 0.12%
C. 0.15%
D. 2.0%

118. The stress strain curve for concrete is considered parabolic by I.S. code upto a strain of
A. 0.0015
B. 0.0020
C. 0.0030
D. 0.0035

119. 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: D more than 1 m

120. Limit state method is based on probable
B. Strength.
C. Both A and B
D. none

Answer: C Both A and B

121. The ratio of permissible shear stress in limit state method oof design and working stress method of design is
A. 25 : 16
B. 5 : 4
C. 16 : 25
D. 4 : 5

122. If no compression steel is used, two suspended bars of minimum ______ diameter should be used to support shear reinforcement
A. 8 mm
B. 10 mm
C. 12 mm
D. 16 mm

123. The load carrying capacity of helically reinforced column as compared to
A. 5% less
B. 10% less
C. 5% more
D. 10% more

124. What is the minimum number of longitudinal bars provided in a reinforced concrete column of circular circular cross-section ?
A. 4
B. 5
C. 6
D. 8

125. For water retaining structures, minimum grade of concrete to be used is
A. M 15
B. M 20
C. M 25
D. M 40

126. A strap footing is a special type of
A. Strip footing
B. Raft footing
C. Combined footing

127. In R.C. footing on soil, the thickness at the edge should not be less than
A. 10 cm
B. 15 cm
C. 20 cm
D. 25 cm

128. What should be the minimum grade of reinforced concrete in and around sea coast construction ?
A. M 35
B. M 30
C. M 25
D. M 20

129. Which is the most important IS code for a Civil Engineer?
A. IS 567
B. IS 456
C. IS 455
D. IS 383

130. The diameter of the column head support a flat slab, is generally kept
A. 0.25 times the span length
B. 0.25 times the diameter of the column
C. 4.0 cm larger than the diameter of the column
D. 5.0 cm larger than the diameter of the column

Answer: A 0.25 times the span length

131. Various types of steel used in RCC
A. Fe 415
B. Fe 250
C. Fe 500
D. All of the above