# RCC Structures Design MCQ Civil Engineering

50 Questions 30 Mins

Following are some of the multiple choice questions on the RCC Structures Design with answers that will help the students in developing their knowledge.

## RCC Structures Design MCQ

### 1. An R.C.C. roof slab is designed as a two way slab if

• It supports live loads in both directions
• The ratio of spans in two directions is less than 2
• The slab is continuous over two supports
• The slab is discontinuous at edges

### 2. The maximum shear stress (q) in concrete of a reinforced cement concrete beam is

• Shear force/(Lever arm × Width)
• Lever arm/(Shear force × Width)
• Width/(Lever arm × Shear force)
• (Shear force × Width)/Lever arm

### 3. 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

• Half of the width of the slab
• Two-third of the width of the slab
• Three-fourth of the width of the slab
• Four-fifth of the width of the slab

• 30
• 35
• 40
• 50

### 5. The reinforced concrete beam which has width 25 cm, lever arm 40 cm, shear force 6t/cm², safe shear stress 5 kg/cm² and B.M. 24 mt,

• Is safe in shear
• Is unsafe in shear
• Is over safe in shear
• Needs redesigning

### 6. Distribution of shear intensity over a rectangular section of a beam, follows:

• A circular curve
• A straight line
• A parabolic curve
• An elliptical curve

### 7. An R.C.C. lintel is spanning an opening of 2 m span in a brick wall. The height of the roof is 2.9 m above the floor level and that of the opening is 2.1 m above the floor level. The lintel is to be designed for self weight plus

• Triangular load of the wall
• UDL of wall
• UDL of wall + load from the roof

• 1.0
• 1.25
• 1.5
• 2.0

### 9. The width of the rib of a T-beam, is generally kept between

• 1/7 to 1/3 of rib depth
• 1/3 to 1/2 of rib depth
• 1/2 to 3/4 of rib depth
• 1/3 to 2/3 of rib depth

### 10. The thickness of base slab of a retaining wall generally provided, is

• One half of the width of the stem at the bottom
• One-third of the width of the stem at the bottom
• One fourth of the width of the steam at the bottom
• Width of the stem at the bottom

### 11. A T-beam behaves as a rectangular beam of a width equal to its flange if its neutral axis

• Remains within the flange
• Remains below the slab
• Coincides the geometrical centre of the beam
• None of these

• 0.2
• 0.3
• 0.4
• 0.5

### 13. In a simply supported slab, alternate bars are curtailed at

• 1/4th of the span
• 1/5th of the span
• 1/6th of the span
• 1/7th of the span

### 14. A part of the slab may be considered as the flange of the T-beam if

• Flange has adequate reinforcement transverse to beam
• It is built integrally with the beam
• It is effectively bonded together with the beam
• All the above

### 15. The advantage of a concrete pile over a timber pile, is

• No decay due to termites
• No restriction on length
• Higher bearing capacity
• All the above

• 12 mm
• 6 mm
• 20 mm
• 22 mm

### 17. [A + (m - 1)ASC] known as equivalent concrete area of R.C.C. is given by

• Modular ratio method
• None of these

### 18. If the size of a column is reduced above the floor, the main bars of the columns, are

• Continued up
• Bent inward at the floor level
• Stopped just below the floor level and separate lap bars provided
• All the above

### 19. After pre-stressing process is completed, a loss of stress is due to

• Shrinkage of concrete
• Elastic shortening of concrete
• Creep of concrete
• All the above

• 0.15 %
• 1.5 %
• 4 %
• 1 %

### 21. According to the steel beam theory of doubly reinforced beams

• Tension is resisted by tension steel
• Compression is resisted by compression steel
• Stress in tension steel equals the stress in compression steel
• All the above

• 8hp/l
• 8hp/l²
• 8hl/p
• 8hl/p²

• R + T
• T - R
• √(R² + T²)
• R - T

• 0.7
• 0.8
• 0.9
• 0.6

### 25. A ribbed slab is provided for

• A plain ceiling
• Thermal insulation
• Acoustic insulation
• All the above

### 26. The thickness of the topping of a ribbed slab, varies between

• 3 cm to 5 cm
• 5 cm to 8 cm
• 8 cm to 10 cm
• 12 cm to 15 cm

• 4 mm
• 5 mm
• 6 mm
• 7 mm

### 28. If C is creep coefficient, f is original pre-stress in concrete, m is modular ratio, E is Young's modulus of steel and e is shrinkage strain, the combined effect of creep and shrinkage is:

• (1 - C) mf - eE
• (C - 1) mf + eE
• (C - 1) mf - eE
• (1 - C) mf + eE

• 0.10 %
• 0.12 %
• 0.15 %
• 0.18 %

### 30. If ‘W’ is the uniformly distributed load on a circular slab of radius ‘R’ fixed at its ends, the maximum positive radial moment at its centre, is

• 3WR²/16
• 2WR²/16
• WR²/16
• None of these

• 51.5
• 52.5
• 53.5
• 54.5

• 0.3 H
• 0.4 H
• 0.5 H
• 0.7 H

### 33. If p₁ and p₂ are mutually perpendicular principal stresses acting on a soil mass, the normal stress on any plane inclined at angle θ° to the principal plane carrying the principal stress p₁, is:

• [(p₁ - p₂)/2] + [(p₁ + p₂)/2] sin 2θ
• [(p₁ - p₂)/2] + [(p₁ + p₂)/2] cos 2θ
• [(p₁ + p₂)/2] + [(p₁ - p₂)/2] cos 2θ
• [(p₁ + p₂)/2] + [(p₁ - p₂)/2] sin 2θ

### 34. Bottom bars under the columns are extended into the interior of the footing slab to a distance greater than

• 42 diameters from the centre of the column
• 42 diameters from the inner edge of the column
• 42 diameters from the outer edge of the column
• 24 diameters from the centre of the column

### 35. The transverse reinforcements provided at right angles to the main reinforcement

• Resist the temperature stresses
• Resist the shrinkage stress
• All the above

### 36. The amount of reinforcement for main bars in a slab, is based upon

• Minimum bending moment
• Maximum bending moment
• Maximum shear force
• Minimum shear force

### 37. For initial estimate for a beam design, the width is assumed

• 1/15th of span
• 1/20th of span
• 1/25th of span
• 1/30th of span

### 38. Lapped splices in tensile reinforcement are generally not used for bars of size larger than

• 18 mm diameter
• 24 mm diameter
• 30 mm diameter
• 36 mm diameter

• 5 cm
• 10 cm
• 15 cm
• 20 cm

• 8.3 kg/cm²
• 7.6 kg/cm²
• 21.5 kg/cm²
• 11.4 kg/cm²

### 41. The width of the flange of a T-beam, which may be considered to act effectively with the rib depends upon

• Overall thickness of the rib
• Centre to centre distance between T-beams
• All the above

### 42. Pick up the incorrect statement from the following: Tensile reinforcement bars of a rectangular beam

• Are curtailed if not required to resist the bending moment
• Are bent up at suitable places to serve as shear reinforcement
• Are bent down at suitable places to serve as shear reinforcement
• Are maintained at bottom to provide at least local bond stress

### 43. The radius of a bar bend to form a hook, should not be less than

• Twice the diameter
• Thrice the diameter
• Four times the diameter
• Five times the diameter

• 2R + T = 60
• R + 2T = 60
• 2R + T = 30
• R + 2T= 30

### 45. If A is the area of the foundation of a retaining wall carrying a load W and retaining earth of weight 'w' per unit volume, the minimum depth (h) of the foundation from the free surface of the earth, is

• h = (W/Aw) [(1 - sin φ)/(1 + sin φ)]
• h = (W/Aw) [(1 + sin φ)/(1 + sin φ)]
• h = (W/Aw) [(1 - sin φ)/(1 + sin φ)]²
• h = √(W/Aw) [(1 - sin φ)/(1 + sin φ)]²

• 300 cm
• 233 cm
• 176 cm
• 236 cm

### 47. Minimum spacing between horizontal parallel reinforcement of the same size should not be less than

• One diameter
• 2.5 diameters
• 3 diameters
• 3.5 diameters

### 48. Minimum spacing between horizontal parallel reinforcement of different sizes, should not be less than

• One diameter of thinner bar
• One diameter of thicker bar
• Twice the diameter of thinner bar
• None of these

### 49. If W is total load per unit area on a panel, D is the diameter of the column head, L is the span in two directions, then the sum of the maximum positive bending moment and average of the negative bending moment for the design of the span of a square flat slab, should not be less than

• WL/12 (L - 2D/3)²
• WL/10 (L + 2D/3)²
• WL/10 (L - 2D/3)²
• WL/12 (L - D/3)²

• 6 mm
• 8 mm
• 10 mm
• 12 mm