# 220+ RCC Structures Design Solved MCQs

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1.

## 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, thebeam

A. Is safe in shear
B. Is safe with stirrups
C. Is safe with stirrups and inclined bars
D. Needsrevision of section
2.

## 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
3.

## 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 smallbars
D. Replacing smaller bars by greater number of greater bars
Answer» C. Replacing larger bars by greater number of smallbars
4.

## 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
5.

A. 3WR²/16
B. 2WR²/16
C. WR²/16
D. None of these
6.

A. 35
B. 25
C. 30
D. 20
7.

A. Square
B. Rectangular
C. Trapezoidal
D. Triangular
8.

A. 0.7
B. 0.8
C. 0.9
D. 0.6
9.

## Pick up the correct statement from the following:

A. Lateralreinforcementin R.C.C. columnsis provided to preventthe 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
10.

## 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
11.

A. 18 mmdiameter
B. 24 mmdiameter
C. 30 mmdiameter
D. 36 mmdiameter
12.

A. Onediameter
B. 2.5diameters
C. 3 diameters
D. 3.5 diameters
13.

A. Straight
B. Dog legged
C. Geometrical
D. Open newel
14.

A. Two times
B. Three times
C. Four times
D. Five times
15.

## 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
16.

## A pre-stressed concrete member is preferred because

A. Its dimensions are not decided from the diagonal tensile stress
B. Large size of long beams carrying large shear force need not be adopted
C. Removal of cracks in the members due toshrinkage
D. All the above
17.

## If the ratio of the span to the overall depth does not exceed 10, the stiffness of the beam will ordinarily be satisfactory in case of a

A. Simply supported beam
B. Continuous beam
C. Cantilever beam
D. None of these
18.

A. WL/8
B. WL²/24
C. WL²/47
D. WL²/16
19.

## If is the net upward pressure on a square footing of side for a square column of side , the maximum bending moment is given by

A. B.M = pb (c - a)/4
B. B.M = pb (b -a)²/4
C. B.M = pb (b -a)²/8
D. B.M = pb (b +a)/8
Answer» C. B.M = pb (b -a)²/8
20.

## 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
21.

## longitudinal bars and lateral stirrups, is

A. Stress in concrete × area of concrete
B. Stress in steel × area ofsteel
C. Stress in concrete × area of concrete + Stress in steel × area of steel
D. None of these
Answer» C. Stress in concrete × area of concrete + Stress in steel × area of steel
22.

## If p1 and p2 are mutually perpendicular principal stresses acting on a soil mass, the normal stress to the principal plane carrying the principal stress p1, is:

A. [(p - p p p sin 2
B. [(p - p p p cos 2
C. [(p p p - p cos 2
D. [(p p p - p /2] sin 2
Answer» C. [(p p p - p cos 2
23.

A. 5 mm
B. 7.5 mm
C. 10 mm
D. 15 mm
24.

## 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
25.

## 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
26.

A. 10 mm
B. 15 mm
C. 20 mm
D. 25 mm
27.

## 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 of column
C. Half the distance of projection
D. One-fourth the distance of projection
Answer» B. 0.1 L from the centre edge of column
28.

A. 0.87
B. 8.50
C. 7.50
D. 5.80
29.

## is the pre-stressed force applied to tendon of a rectangular pre-stressed beam whose area of cross section is and sectional modulus is. The minimum stress on the beam subjected to a maximum bending moment is

A. f = (P/A) -(Z/M)
B. f = (A/P) -(M/Z)
C. f = (P/A) - (M/Z)
D. f = (P/A) - (M/6Z)
Answer» C. f = (P/A) - (M/Z)
30.

## 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:

A. (1 - C)mf - eE
B. (C - 1)mf + eE
C. (C - 1)mf - eE
D. (1 - C)mf + eE
Answer» B. (C - 1)mf + eE
31.

## In a pre-stressed member it is advisable to use

A. Low strength concrete only
B. High strength concrete only
C. Low strength concrete but high tensile steel
D. High strength concrete and high tensile steel
Answer» D. High strength concrete and high tensile steel
32.

## 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

A. Triangular load of the wall
B. UDL of wall
C. UDL of wall + load from the roof
33.

## The minimum clear cover for R.C.C. columns shall be

A. Greater of 40 mm or diameter
B. Smaller of 40 mm or diameter
C. Greater of 25 mm or diameter
D. Smaller of 25 mm or diameter
Answer» C. Greater of 25 mm or diameter
34.

## 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
35.

## 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
36.

## An R.C.C beam of 25 cm width has a clear span of 5 metres and carries a U.D.L. of 2000kg/m inclusive of its self weight. If the lever arm of the section is 45 cm., the beam is

A. Safe in shear
B. Is safe with stirrups
C. Is safe with stirrups and inclinedmembers
D. Needsrevision ofthe section
37.

## 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
38.

## A pre-cast pile generally used, is

A. Circular
B. Square
C. Octagonal
D. Square with corners chamfered
Answer» D. Square with corners chamfered
39.

## The spacing of transverse reinforcement of column is decided by the following consideration.

A. The least lateral dimension of the column
B. Sixteen timesthe diameter of the smallest longitudinal reinforcing rods in the column
C. Forty-eight times the diameter of transverse reinforcement
D. All the above
40.

## The self-weight of the footing, is

A. Not considered for calculating the upward pressure onfooting
B. Also considered for calculating the upward pressure onfooting
C. Not considered for calculating the area of the footing
D. Both (b) and(c)
Answer» A. Not considered for calculating the upward pressure onfooting
41.

## 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
42.

## If the bearing capacity of soil is 10 tonnes/cm2 and the projection of plain concrete footing from walls, is a cm, the depth D of footing is

A. D = 0.0775 a
B. D = 0.775 a
C. D = 0.775 a
D. D = 0.775 a2
Answer» B. D = 0.775 a
43.

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

A. Shrinkage of concrete
B. Elastic shortening of concrete
C. Creep of concrete
D. All the above
44.

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

A. 1/4th of thespan
B. 1/5th of thespan
C. 1/6th of thespan
D. 1/7th of thespan
45.

A. R + T
B. T - R
C. 2 +T2)
D. R - T
46.

## If p1 and P2 are effective lateral loadings at the bottom and top exerted by a level earth subjected to a super-load on the vertical face of height h of a retaining wall, the horizontal pressure p per unit length of the wall, is

A. [( - )/2] h
B. [( + )/4] h
C. [( + )/2] h
D. ( - h
Answer» C. [( + )/2] h
47.

## In the zone of R.C.C. beam where shear stress is less than 5 kg/cm2 , nominal reinforcement is provided at a pitch of

A. One-half lever arm of the section
B. One-third lever arm of the section
C. Lever arm of the section
D. One and half lever arm of the section
Answer» C. Lever arm of the section
48.

## 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
49.

## Long and short spans of a two way slab are ly and lx and load on the slab acting on strips parallel to lx and ly be wx and wy respectively. According to Rankine Grashoff theory

A. (wx/wy) = (ly/lx)
B. (wx/wy) = (ly/lx)²
C. (wx/wy) = (ly/lx)4
D. None of these
50.

A. Three times
B. Four times
C. Five times
D. Six times
51.

## 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
52.

A. WR²/16
B. 2WR²/16
C. 3WR²/16
D. 5WR²/16
53.

## 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

A. h = (W/Aw)[(1 - )/(1 + sin )]
B. h = (W/Aw) [(1 + )/(1 + sin )]
C. h = (W/Aw) [(1 - )/(1 + sin )]²
D. h W/Aw) [(1 - )/(1 + sin )]²
Answer» C. h = (W/Aw) [(1 - )/(1 + sin )]²
54.

A. 0.496%
B. 0.596 %
C. 0.696 %
D. 0.796%
55.

A. m = 700/3C
B. m = 1400/3C
C. m = 2800/3C
D. m = 3500/3C
56.

## 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
57.

A. Drop panel
B. Capital
D. None of these
58.

A. P/A
B. A/P
C. P/2A
D. 2A/P
59.

A. 50 cm
B. 75 cm
C. 100 cm
D. 120 cm
60.

A. WL/P
B. WL/2P
C. WL/3P
D. WL/4P
61.

A. 200 cm
B. 205 cm
C. 210 cm
D. 230 cm
62.

## If q is the punching shear resistance per unit area a, is the side of a square footing for a column of side b, carrying a weight W including the weight of the footing, the depth (D) of the footing from punching shear consideration, is

A. D = W (a - b)/4a²bq
B. D = W (a² -b²)/4a²bq
C. D = W (a² -b²)/8a²bq
D. D = W (a² - b²)/4abq
Answer» B. D = W (a² -b²)/4a²bq
63.

A. 1/15th ofspan
B. 1/20th ofspan
C. 1/25th ofspan
D. 1/30th ofspan
64.

## If the length of a combined footing for two columns l metres apart is L and the projection on the left side of the exterior column is x, then the projection y on the right side of the exterior column, in order to have a uniformly distributed load, is (where is the distance of centre of gravity of column loads).

A. y = L - (l - )
B. y = L/2 + (l - )
C. y = L/2 - (l + )
D. y = L/2 - (l - )
Answer» D. y = L/2 - (l - )
65.

A. h/4
B. h/3
C. h/2
D. 2h/3
66.

## If the tendon is placed at an eccentricity e below the centroidal axis of the longitudinal axis of a rectangular beam (sectional modulus Z and stressed load P in tendon) the stress at the extreme top edge

A. Is increased byPZ/e
B. Is increased byPe/Z
C. Is decreased by Pe/Z
D. Remainsunchanged
Answer» C. Is decreased by Pe/Z
67.

A. 150 KN/mm2
B. 200 KN/mm2
C. 250 KN/mm2
D. 275 KN/mm2
68.

## Design of a two way slab simply supported on edges and having no provision to prevent the corners from lifting, is made by

A. Rankine formula
B. Marcus formula
C. Rankine Grashoff formula
D. Grashoffformula
69.

## 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
70.

## As per IS : 456, the reinforcement in a column should not be less than

A. 0.5% and not more than 5% of cross-sectional area
B. 0.6% and not more than 6% of cross-sectional area
C. 0.7% and not more than 7% of cross-sectional area
D. 0.8% and not more than 8% of cross-sectional area
Answer» D. 0.8% and not more than 8% of cross-sectional area
71.

A. 1400 kg/cm2
B. 190 kg/cm2
C. 260 kg/cm2
D. 230 kg/cm2
72.

## 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 diametersfrom the inner edge of the column
C. 42 diametersfrom the outer edge ofthe column
D. 24 diametersfrom the centre of the column
Answer» C. 42 diametersfrom the outer edge ofthe column
73.

## Pick up the assumption for the design of a pre-stressed concrete member from the following:

A. A transverse plane section remains a plane afterbending
B. During deformation limits, Hook'slaw is equally applicable to concrete as well asto steel
C. Variation of stress in reinforcement due to changes in external loading is negligible
D. All the above
74.

## 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
75.

A. 30
B. 35
C. 40
D. 50
76.

A. 30°
B. 45°
C. 60°
D. None of these
77.

## 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
78.

A. 4.5 m
B. 4.0 m
C. 3.5 m
D. 3.0 m
79.

## If L is the effective span of a R.C.C. beam which is subjected to maximum shear qmax at the ends, the distance from either end over which stirrups for the shear, are provided, is

A. (L/2) (1 - 3/qmax)
B. (L/3) (1 - 5/qmax)
C. (L/2) (1 - 5/qmax)
D. (L/2) (1 - 2/qmax)
Answer» C. (L/2) (1 - 5/qmax)
80.

## The angle of internal friction of soil mass is the angle whose

A. Tangent is equal to the rate of the maximum resistance to sliding on any internal inclined plane to the normal pressure acting on theplane
B. Sine is equal to the ratio ofthe maximum resistance to sliding on any internal inclined plane to the normal pressure acting on the plane
C. Cosine is equal to the ratio of themaximum resistance sliding on any internal inclined plane to the normal pressure acting on the plane
D. None of these
Answer» A. Tangent is equal to the rate of the maximum resistance to sliding on any internal inclined plane to the normal pressure acting on theplane
81.

A. 25
B. 30
C. 35
D. 40
82.

## If T and R are the tread and rise of a stair which carries a load w per square metre on slope, the corresponding load per square metre of the horizontal area, is

A. w (R + T)/T
B. w (R² + T²)/T
C. w (R + T)/T
D. w (R/T)
Answer» B. w (R² + T²)/T
83.

## 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
84.

A. 10
B. 15
C. 20
D. 25
85.

A. 8hp/l
B. 8hp/l²
C. 8hl/p
D. 8hl/p²
86.

A. 200 cm
B. 300 cm
C. 150 cm
D. 100 cm
87.

## The steel generally used in R.C.C. work, is

A. Stainless
B. Mild steel
C. High carbon steel
D. High tensionsteel
88.

## If the ratio of long and short spans of a two way slab with corners held down is r, the actual reduction of B.M. is given by

A. (5/6) (r/1 + r²) M
B. (5/6) (r²/1 + r²)M
C. (5/6) (r²/1 + r3)M
D. (5/6) (r²/1 + r4) M
Answer» D. (5/6) (r²/1 + r4) M
89.

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

A. Flange has adequate reinforcement transverse tobeam
B. It is built integrally with the beam
C. It is effectively bonded together with the beam
D. All the above
90.

A. 10 %
B. 15 %
C. 20 %
D. 25%
91.

## Total pressure on the vertical face of a retaining wall of height per unit run exerted by the retained earth weighing per unit volume, is

A. wh [(1 - )/(1 + sin )]
B. wh² [(1 - )/(1 + sin )]
C. wh² [(1 - )/2(1 + sin )]
D. wh²[(1 - )/3(1 + sin )]
Answer» C. wh² [(1 - )/2(1 + sin )]
92.

## A singly reinforced beam has breadth b, effective depth d, depth of neutral axis n and critical neutral axis n1. If fc and ft are permissible compressive and tensile stresses, the moment to resistance of the beam, is

A. bn (fc/2) (d - n/3)
B. Atft (d - n/3)
C. ½ n1 (1 - n1/3) cbd²
D. All the above
93.

A. 5 cm
B. 10 cm
C. 15 cm
D. 20 cm
94.

## If l1 and l2 are the lengths of long and short spans of a two way slab simply supported on four edges and carrying a load w per unit area, the ratio of the loads split into w1 and w2acting on strips parallel to l2 and l1 is

A. w1/w2 = l2/l1
B. w1/w2 = (l2/l1)²
C. w1/w2 = (l2/l1)3
D. w1/w2 = (l2/l1)4
95.

A. Nil
B. 75 kg/m3
C. 150 kg/m2
D. 200 kg/cm2
96.

## If Ac, Asc and A are areas of concrete, longitudinal steel and section of a R.C.C. column and m and c are the modular ratio and maximum stress in the configuration of concrete, the strength of column is

A. cAc + m cAsc
B. c(A - Asc) + m cAsc
C. c[A + (m - 1)ASC]
D. All the above
97.

## On an absolutely rigid foundation base, the pressure will

A. Be more at the edges of thefoundation
B. Be uniform
C. Not be uniform
D. Be zero at the centre of the foundation
98.

A. 4 mm
B. 5 mm
C. 6 mm
D. 7 mm
99.

A. wl²/4
B. wl²/8
C. wl²/10
D. wl²/12
100.

## If P kg/m2 is the upward pressure on the slab of a plain concrete footing whose projection on either side of the wall is a cm, the depth of foundation D is given by

A. D = 0.00775 aP
B. D = 0.0775 aP
C. D = 0.07775 aP
D. D = 0.775 Pa
Answer» A. D = 0.00775 aP