IS.

md Live loadObjective Type Questions

11.1. Design of R.C.C. cantilever beams, is based on the resultant force at(a) fixed end(b) free end(c) mid span(d) mid span and fixed support.

11.2. Design of R.C.C. simply supported beams, carrying u.d.l., is based on the resultant BM at{a) supports(b) mid span(c) every section(d) quarter span.

11.3. 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.

11.4. Spacing of stirrpus in a rectangular beam is(fl) 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.11.5. The thickness of the flange of a tee

beam of a ribbed slab is assumed a s '(a) width of the rib(b) depth of the rib(c) thickness of the concrete

topping(d) half the thickness of the rib.

11.6. If T and R are tread and rise respectively of a stair, then(a) 2R + T = 60(b) R + 2T = 60(c) 2R + T = 30(d)R + 2T = 30.

11.7. The maximum area of tension reinforcement in beam shall not exceed (a) 0.15% (b) 1.5%(c) 4% (d) 1%.

11.8. The length of the straight portion of a bar beyond the end of the hook, should be at least(a) twice the diameter(b) thrice the diameter(c) four times the diameter(d) seven times the diameter.

11.9. Design of a two way slab simply supported on edges and having no provision to prevent the corners from lighting is made by(a) Rankine formula(ib) Marcus formula(c) Rankine Grashoff formula(d) Rankine-Marcus formula.

11.10. The system in which high tensile alloy steel bars (silica manganese steel) are used as pre-stressing tendons, is known as(a) Freyssinet system(b) Magnet-Blaton system(c) C.C.L. standard system(d) Lee-McCall system.

11.11. Side face reinforcement shall beprovided in the beam when the depth of the web in a beam exceeds (ia) 50 cm (b) 75 cm(ic) 100 cm (d) 120 cm.

11.12. In a pretressed concrete member it is advisable to use(ia) 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.

11.42 Civil Engineering (Objective Type)11.13. Top bar are extended to the

projecting parts of the combined footing of two columns L distance 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.11.14. Columns may be made of plain

concrete if their unsupported lengths do not exceed their least interal dimension(a) two times (b) three times (c) four times (d) five times.

11.15. The shear reinforcement in R.C.C. is provided to resist(a) vertical shear(b) horizontal shear(c) diagonal compression(d) diagonal tension.

11.16. Total pressure on the vertical face of retaining wall of height h cuts parallel to free surface and from the base at a distance of(n)h/4 (b )h /3(c) h / 2 (d) 2/2/3.

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

{a) to of rib depth

1 1(.b) to of rib depth

1 3(c) to of rib depth

1 2(d) and of rib depth.

11.18. 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 central axis.

11.19. Through the effective depth of a T-beam is the distance between the top compression edge to the centre of the tensile reinforcement, for heavy loads, it is taken as

1(a) - t h of span

(b) J^ th of span

1(c) ^ t h f span

{d) ^ t h of span.

11.20. Steel beam theory is used for(a) design of simple steel beams(b) steel beams encased in concrete(c) doubly reinforcement beams

ignoring compressive stress in concrete

(d) beams if shear exceeds 4 times allowable shear stress.

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

Shear force Lever arm x Width

Lever arm Shear force x Width________Width________Lever arm x Shear force

Lever arm x Width Shear force

11.22. A pile of length L carrying a uniformly distributed load iu per metre length is suspended at two points, the maximum, B.M. at the centre of the pile or at the points of suspension, is

RCC Structure Design 11.43

jamixis.?pth of a ween the he centre nent, for

1 for beams concrete t beams stress in

> 4 times

ss (q) in cement

T in g a i w per I at two L at the ; points

(fl)

(c)

iv L

wL2

(b)

(d)

w L~2A

wL247 ' ' 26

11.23. 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(fl) 28 d (b) 38 d(c) 48 d (d) 58 d.

11.24. 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) by zero at the centre of the

foundation.11.25. As per I.S. 456 the pH value of

water shall be(a) less than 6(b) equal to 6(c) not less than 7(d) equal to 7.

11.26. Pick up the correct statement from the following :(a) A pile is a slender member

w hich transfers the load through its lower end on a strong strata

(b) A pile is a slender member which transfers its load to the surrounding soil

(c) A pile is a slender member which transfers its load by friction

(d) A pile is a cylindrical body of concrete which transfers the load at a depth greater than its width.

11.27. Pick up the incorrect statement from the following :

Tensile reinforcem ent bars of rectangular beam (fl) are curtailed if not required to

resist the bending moment(b) are bend up at suitable places

to serve as shear reinforcement(c) are bent down at suitable places

to serve as shear reinforcement(d) are maintained at bottom to

provide at least local bend stress.11.28. Pickup the incorrect statement

from the following :The intensity of horizontal shear stress at the elemental part of a beam section, is directly proportional to(a) shear force(b) area of the section(c) distance of the C.G. of the area

from its neutral axis(d) moment of the beam section

about its neutral axis.11.29. If the length of a wall on either side

of lintel opening is at least half ofits effective span L, the load Wcarried by the lintel is equivalentto the w eight of brickw orkcontained in an equilateraltriangle, producing a maximumbending moment

WL , x WL(a) (b)

(c)

2WL

(d)

4WL

11.30. A dome is a(a) shell of revolution(b) shell of generation(c) plate(d) folded plate.

11.31. In the design of retaining wall, factor of safety against overturning should be taken as(a) 2.5 (b) 3.0(c) 1.5 (d) 4.5.

11.44 Civil Engineering (Objective Type)11.32. The least coefficient of thermal

expansion of coricrete is with the aggregate of(a) sandstone (b) limestone (c) quartzite (d) basalt.

11.33. The value of bond stress for bars in compression, as compared to value of bond stress for bars in tension, should be(a) decreased by 25%(b) kept equal(c) increased by 25%(d) decreased by 10%.

11.34. Portland pozzonola cement conforms to(a) IS : 8041-1978(b) IS : 455 - 1976(c) IS : 8112 - 1976(d ) IS : 1489 - 1976.

11.35. The minimum thickness of flat slab should be(a) 75 mm (b) 100 mm(c) 200 mm (d) 125 mm.

11.36. Balanced section is that in which the maximum stresses in steel and concrete reach simultaneously to(a) allowable stress(b) ultimate stress(c) yield stress(d) breaking stress.

11.37. Lap reinforcing splices should not be used for bars(a) larger than 25 mm (b) smaller than 16 mm (c) smaller than 10 mm (d) larger than 36 mm

RCC Structure Design 11.45

lation is

of beam 'ater, the than the

upended>eng/litre g/litre n will be ien (//D)

f shear stirrups

depth of

ing wall ?nerally

Tierally,

van 11 lan 6. rear of

11.47. The percentage of steel incompression in doubly reinforced beam should be of total cross- sectional area as maximum upto (a) 0.4% (b) 8%(c) 0.8% (d) 4%.

11.48. A stagging consists of two identical columns fixed at the footings as shown in Fig. 1. The point of contraflexure occurs in each column at Fig. 1

TH

i

(rt) one-fourth height (>) mid-height(c) three-fourth height(d) 5/8 of the height.

11.49. Bending moment on top of each column in Fig. 1 will be(a) Ph/4 {b) Ph/6(c) Ph/8 (d) Ph/12.

11.50. The reduction coefficient of column Cr is expressed by (b is the least lateral dimension of column, the effective length)

(fl) Cr = 1.25-

(1b) Cr = 1.25 +

(c)Cr = 1.25 + - 4A

(rf)Cr = 1.25 + -

L

11.51. Maximum reinforcement area of tension reinforcement shall not exceed(a) 0.4 bd (b) 0.02 bd(c) 0.2 bd (rf) 0.04 bd.

11.52. The creep coefficient at 28 days loading age may be taken as(fl) 1.6 (b) 1.1(c) 2.2 (d) 1.0.

11.53. When passive resistance of soil is considered in the design of retaining wall, the factor of safety against sliding should not be less than(a) 1.7 (b) 1.5(c) 3 (d) 2.

11.54. Column should be designed for (fl) zero eccentricity(b) minimum 20 mm(c) minimum 50 mm eccentricity(d) maximum 10 mm eccentricity.

11.55. The characteristic strength of 15 N/mm2 in M15 indicates the strength that is(fl) tensile (b) compressive(c) flexural (d) shear.

11.56. When R.C.C. footing is not to extend in the plot of the neighbouring house, the type of footing preferred is(fl) cellular raft footing(b) inverted flat not footing(c) both of the above(d) strap footing.

11.57. When xv is less than critical shear stress t the minimum shear reinforcement is provided as (notations carry their usual meaning)

(fl)0.4

fy(b)

a b l_ oa

fulil t

(C)I.

A ^ 0 4sv fy id)

11.46 Civil Engineering (Objective Type)11.58. Maximum spacing for shear

reinforcem ent along axis of a member should not exceed for vertical stirrups by(a) 0.75 d (b) d(c) 1.25 d (d) 1.5 d.

11.59. The minimum depth of foundation for load bearing wall should be taken as(a) 40 cm (b) 80 cm(c) 150 cm (d) 225 cm.

11.60. The loss in pre, tress force is about(n) 5.1% (b) 15 to 20%(c) 10% (d) 30 to 35%.

11.61. The depth of the section of stair should be taken as(a) m inim um thickness per

pendicular to the soffit (.b) minimum thickness parallel to

the soffit(c) maximum thickness parallel to

the soffit(d) minim um thickness per

pendicular to the soffit.11.62. The 'L / d' ratio for a sim ply

supported beam to be 'deep' is (a) less than 1 (b) more than 5 (c) less than 2 (d) more than 10.

11.63. The anchorage value of standard Zi-hook should be ( (b) 32(j)(c)481

= 1 .11.71. When quality of steel in a beam

RCC Structure Design 11.47

section is less than required, the section is called(a) over-reinforced(b) balanced(c) under-reinforced(d) critical.

11.72. C oncentrations showingmaximum permissible value to neutralize 200 ml water using phenolphthalein as indicator should not need more than(a) 2 ml of 0.1 normal NaOH(b) 1 ml of 0.2 normal NaOH(c) 1 ml of 0.1 normal NaOH(d) 2 ml of 0.2 normal NaOH.

11.73. The bearing stress at bends for limit state m ethod com pared to working stress method of design(a) 1.5 times less(b) 1.5 times more(c) 2.5 times more (id) 2.5 times less.

11.74. The estimate of tensile strength from com pressions strength of concrete may be done by

()/, = 0 . 7 ^ (&)/=

(C) f c r = Q 'J f ck ( d ) f c r = J 0 7 U -11.75. The width of flange for T-beam

may be taken as(fl) L0/6 + bw + 6Df(b) L0/6 + bw + Dt(c) L0/3 + 2bw + 6Dt(d) L0/6 + 2bw + Df.

11.76. The width of flange for L-beam may be taken as(fl) L0/24 + 2bw + Df(b) L0/12 + bw + 3Dt(c) L0/24 + bw + Df(d) L0/12 + 2bw + Df.

11.77. Moist sand may contain surface water by mass upto

(fl) 7.5% (b) 5.0%(c) 2.5% (d) 1.25%.

11.78. The maximum area of compression reinforcement in a beam of cross- section B x D is limited to(rt) 0.02 BD (b) 0.03 BD(c) 0.04 BD (d) 0.05 BD.

11.79. The approximate value of torsion constant k for a box of depth d, w idth b, and having uniform thickness t, is

(fl)

(c)

2 dbt d + b

3 b2d2t

(b)

(d)

2 d V f d + b

3 b2d2td + b b2 +d2 '

11.80. The minimum length of the side or diameter of the column base shall not be less than(fl) (d + 75) mm (.b) 1.2 (d - 7.5) mm(c) 1.5 (d + 7.5) mm(d) 1.6 (d + 75) mm.

11.81. The reduced level of third floor of a building near a column is 205.350 m. The reduced levels of the undersides of four beams supporting the fourth floor framing into the column mutually perpendicular are 208.350 m, 208.450 m, 208.500 m and 208.550 m. The supported length of the column is(fl) 3.000 m (b) 3.100 m(c) 3.150 m (d) 3.200 m.

11.82. When bending occurs about both axes of the member, the value of f be in the formula

A. + J k > ipc n

is taken(fl) higher value (h) lower value(c) sum of the two(d) difference of the two.

11.48 Civil Engineering (Objective Type)11.83. The designed transverse shear in

lacing is assumed as(a) 2.5% of axial load (,b) 3% of axial load(c) 3.5% of axial load(d) 4% of axial load.

11.84. The distance of the critical section for shear from the periphery of the column or drop panal is at a distance

() J (b) |

2 J

(c) | (

RCC Structure Design 11.49

ace rein- eep beam

n of the : member

id 60 id 80. bars, the less may

i column pressive Secant

a factor

?ressive repared ) grade should

1 work er and ; and >uld be

11.96. The outstand of stiffeners should be(a) 6 t (b) 8 t(c) 10 t (d) 12 t.

11.97. The maximum deflection of astructure should not norm ally exceed lesser of the span/350 or (a) 10 mm (b) 15 mm(c) 20 mm (d) 25 mm.

11.98. The overall depth of a solid slab is20 cm and effective depth is 15 cm. The horizontal distance between parallel main reinforcement should not be more than(a) 30 cm (b) 40 cm(c) 45 cm (d) 60 cm.

11.99. The grade of concrete generally notused in the reinforced concrete is () M10 (b) M15(c) M20 (d) M40.

11.100. The ratio of the effective lengths of two columns, one effectively held in position at one end and partial restrained at the other end, and the other effectively held in position at one end and free at the other end, is

1()

f -11.101. The thickness of flat lacing bars for

single lacing is taken

(C)11.102.

11.103.

5

35 40 'The development length of each bar of three bars bundled together is increased by(a) 10% (b) 20%(c) 33% (d) 50%.

If f bt and/, are the numerical values

of bending tension and shear stresses, he equivalent stress f e, is

() 1[fu+f! W l//n +/>

11.104. The greater clear dimension of webthickness't' should not exceed (a) 180 t (b) 200 t(c) 240 t (d) 270 t.

11.105. For nominal mix concrete M15, the required weight of fine and coarse aggregates is 350 kg and the volume of water is(a) 30 litres (b) 32 litres(c) 34 litres (d) 45 litres.

11.106. The slenderness effect of a wall is considered if the effective height of the wall exceeds the thickness(ia) 8 times (b) 10 times(c) 12 times (d) 16 times.

11.107. The staggered pitch is the distance between two consecutive rivets measured(a) parallel to the direction of stress

in the member(b) perpendicular to the direction

of stress in the member(c) diagonally(d) none of the above.

11.108. The thickness of flat lacing bars for single being is, taken

^ 4 5 ^ 4 0 11.109. The anchorage value of standard

U-type hook of a reinforcing bar of diameter d in tension, is(a) 8 d (b) 12 d

(c) 16 d (d) 20 d.11.110. The maximum bending moment in

a purlin of length L when subjected to a distributed load w, is assumed

11.50 Civil Engineering (Objective Type)

(fl)wL6

wL(c )To

( ) f

W) f -11.111. If the ratio of effective span to overall

depth of a simply supported beam is less than 1, the lever arm is(fl) 0.3/ (b) 0.4 /(c) 0.5 I (d) 0.6 /.

11.112. If the ends of the compression flanges of sim ply supported girders are fully resistrained against interal bending, the effective length is taken as(a) span (b) 0.85 x span(c) 0.7 x span (d) 0.5 x span.

11.113. In limit state method, the design bond stress of M 30 grade concrete for plain bars in tension, is(fl) 1.0 N/mm2(b) 1.2 N/mm2(c) 1.4 N/mm2(rf) 1.5 N/mm2.

11.114. The slenderness ratio of single angle discontinous struts connected by a single rivet or bolt, shall not exceed(a) 110 (b) 130(c) 150 (d) 180.

11.115. The ratio ~ of the lacing bars for

compression members shall not exceed (fl) 80 (b) 120(c) 145 (rf) 200.

11.116. In adverse circum stances, the reinforced concrete member immersed in sea water or subjected to sea spray, the maximum perm issible cover for the reinforcing bars, should not exceed

. (fl) 50 mm (b) 60 mm(c) 70 mm (d) 75 mm.

11.117. The spans of filter joists supporting a slab may be considered

approximately equal if the longest span does to exceed the shortest span more than (fl) 5% (b) 10%(c) 15% (d) 20%.

11.118. The pH value of water to be used in concrete shall generally be(fl) not more than 7(b) not less than 6(c) not less than 5(d) not across than 6.

11.119. If D is the overall thickness of the slab, the diameter of the reinforcing bars, should not exceed

() ~5 D

{ c )\ D

(b) 7 D

(d) r D.

11.120. In case of continous beams, the distance between the points of zero moment, may be obtained as(fl) 0.5 I {b) 0.6 /(c) 0.7 I (d) 0.8 /.

11.121. The maximum horizontal deflection of a column of actual length L, when subjected to lateral forces, may be upto

L L125

325 (d) 40011.122. The thickness of flat lacing bars for

double lacing is taken

30 1

(c) 6011.123. The individual part of the

structures is subjected to a load test for 24 hours by applying a load equal to full dead of the structure plus

RCC Structure Design 1151

(a) imposed load(b) 1.15 times imposed load(c) 1.25 times imposed load(d) 1.3 times imposed load.

124. Dispersion of load through the flange to web is considered as dispersed uniformly at an angle 0 is(a) 15 (b) 20(c) 25 (d) 30.

125. In the formula a + bk for the calculation of the net effective section of single tee in tension connected by flange to the same side of the gusset, the value of 'k' is taken

()1

(b)

(c)

1 + 0 .25- fl

1

1 + 0.20 '(d)

1 + 0.35- fl

1

1 + 0.5

11.126. As perflIS

a

be accepted after 24 hour load test, provided the maximum deflection in mm is less than

(fl)

(c)

10 L2 D

30 L2

(b)

(d)

20 L2 D

40 L2

800-1982, the coefficient of expansion for steel per degree centigrade per unit length, is (fl) 0.000011 (b) 0.000012 (c) 0.000013 (rf) 0.000014.

11.127. The distance between rivet line and the nearest edge of a joint not exposed to weather, is taken(fl) 6 t (b) 8 t(c) 10 t (d) 12 t.

11.128. If f ck is the characteristic cube strength of concrete in N/mm2, the modulus of elasticity of structural

concrete Ec = a j f a where thevalue of fl, is(fl)5600 (b) 5700(c) 5800 (d) 5900.

11.129. If L is the effective span in metres and D is overall depth of the section in mm, the structure may

D D11.130. In compression members, the lap

length of a bar should not be less than(fl) 12

11.52 Civil Engineering (Objective Type)(a) 200 kN/mm2(>) 225 kN/mm2 (c) 250 kN/mm2(d)275 kN/mm2.

11.136. If the end of a beam of span L carrying a designed load W is partially restrained by a built up wall, it is designed to resist the negative moment at the face of the support, equal to

()

(c)

WL12

WL(b)

(d)

WL16

WL20 v ' 24 -

11.137. Columns are designed for a mini-1

mum eccentricity equal to (unsupported length of the column), subjected to a minimum of (a) 5 mm (b) 10 mm(c) 15 mm (d) 20 mm.

11.138. The average 23 days compressivestrength of at least three 15 cm concrete cubes prepared with available water as compared to the average strength of three similar concrete cubes prepared with distilled water, should be at least (a) 70% (b) 80%(c) 90% (d) 95%.

11.139. For concreting of heavily reinforcedsection without vibration, the workability of concrete should be (a) very low (b) low(c) medium (d) high.

11.140. The value of the constant K in the

formula As = fQr determiningh

the m inim um area of tension reinforcement in a beam is (a) 0.95 (b) 0.90(c) 0.85 (d) 0.80.

11.141. N orm ally maxim um value of span/depth ratio for sim ply supported beam is taken as

(a) 10 (b) 15(c) 20 (d) 25.

11.142. In which case the bond value is generally high(a) very smooth steel bars(b) polished steel bars(c) rushed steel bars(d) for steel bars.

11.143. The reinforcem ent bars are generally bent(a) by heating(b) by welding(c) manually by vising a lever(d) by casting in slope.

11.144. In case of a dome subjected to uniformly distributed load the value of angle 0 below which hoop stress at the base w ill be compressive, is(a) 42 (b) 45(c) 48 (d) 52.

11.145. In case of past tensioned prestressed concrete beams another cones are designed primarily for(a) torsion(b) hoop tension(c) hoop compression(d) bearing compression

11.146. While designing RCC piles as a column it is considered as(a) hinged at both ends(b) fixed at both ends(c) fixed at one end and hinged at

the other end(.d) restrained throughout.

11.147. Peeling is(a) a form of light ramming(b) the addition of w ater and

remixing of concrete of mortar which has started to stiffen

(c) The operation of finishing a fresh concrete on mortar surface by use of a float

(d) a process in which the flakes

RCC Structure Design 11.53

nd value is

bars

bars are

a lever

bjected to I load the rhich hoop

w ill be

*ned pre- s another narily for

>iles as a as

linged at

t.

ingter and f mortar stiffen shing a mortar ate flakes

of mortar broken away from a concrete surface such as by deterioration or by adherence of surface mortar as forms are removed.

11.148. In a RCC column when a lap has to be provided to make the bars equal to the full length of the column, the lap between the bars, in any case, should not be less than (fl) 8 times the diameter of bars(b) 12 times the diameter of bars(c) 20 times the diameter of bars(d) 24 times the diameter of bars.

11.149. The anchorage value of a standard hook of diameter d with angle of bend 0 is given by

(a)

(c)

dx 6 189 4

11.54 Civil Engineering (Objective Type)in steel and concrete, m is the modular ratio and d is the effective depth of the beam, then depth of critical neutral axis n is given by

() d + n (b)mo.

(C)mo,.,cb n + 1 me(d) cb

d + n

n + 1d - n KU> asf d - 1 '

11.162. Continous beams are designed as deep beams in case depth/span ratio exceeds(a) 0.4 (b) 0.8(c) 1.2 (d) 1.6.

11.163. A column is considered as a long column if its slenderness ratio (effective length/least radius of gyration) exceeds(a) 12 (b) 20(c) 24 (d) 30.

11.164. A prestressed rectangular section beam having cross sectional area A is provided w ith a tendon prestressed by force P, through its centroidal longitudinal axis. The stress (compressive) induced in the concrete would be

(a)

(c)

2P(b)

2P

(d) 5 mm + aggregate size.11.167. The IS 456 recommendation for

m inim um reinforcem ent in a column shall not apply if the ratio of length to least radius of gyration is less than(a) 18 (b) 16(c) 15 (d) 12.

11.168. The pitch of the helical turns in acircular column should not exceeds (a) 50 mm (b) 75 mm(c) 100 mm (d) 150 mm.

11.169. As compared to an over-reinforced section, an under-reinforced section is preferred because(a) There is less chance of failure(b) It is more economical(c) It cause only com pression

failure for which the chances are least

(d) It cause tension failure for w hich the chances are generally less.

11.170. In above case the minimum value of bond stress occurs at (a) End A

(b) At3L

from A

11.165. In w hich of the follow ing construction, the unit mould method is used?(a) Precast construction(b) Cantilever construction(c) Post tensioned construction(d) Cast-in-situ construction

11.166. M inimum horizontal spacing between bars is :()3 4>(b) 2 (J)(c) aggregate size

(c) At from A

(d) At B.11.171. The ratio of the deflections at the

centre of a simply supported beam to that with both ends fixed is(a) 2 (b) 1 / 2(c) 5 (d) 1/5.

11.172. The point of actual curtailment is away from the theoretical point of cut off(a) 2d (b) 12 (J)(c) 30 (d) 2 Ld.

11.173. In which case the maximum value of span/depth ratio would be least

RCC Structure DesigtT 11.55

(a) Sim ply supported slabs spanning in one direction

(b) Sim ply supported slabs spanning in two directions

(c) Continous slabs spanning in two directions

(d) Cantilever slabs.11.174. In a doubly reinforced beam the

maximum shear stress occur(a) Along neutral axis(b) Along the centroid(c) One planes between neutral

axis and the compressive reinforcement

(d) On planes between neutral axis and the tensile reinforcement.

11.175. Archorage value for 90 bend is(a) 5

11.56 Civil Engineering (Objective Type)(b) d = 0.775 flVP(c) d = 0.0775 flVP(d)d = 0.00775 flVP.

11.186. What is the minimum cover for steel in beams?(a) 12 mm (b)

RCC Structure Design 11.57m theity over te curve

icitT-beam/

cement

gregatethermal

me.angular s flange

; .within

i within

mentin

lined is

horizontal, and is the angle of repose then the coefficient of pressure Cp is given by

l-s in 0 l + sin0

1-COS0 1 + COS011.198. The slenderness ratio of a

reinforced cem ent concretecolumn is generally taken as

Length ( )--------------------------

(b)

(c)

(d)

Radius of gyration

LengthBreadthLengthWidth

LengthLeast latral dimension '

11.199. % increase in bond stress for ton steel(a) 20 (b) 30(c) 50 (d) 60.

11.200. The cement for concrete work is generally declared as 'unfit for use', if the moisture absorbed is more than(a) 0.5% (b) 1%(c) 2.5% (d) 5%.

11.201. In a pull out test, shown in Fig. 3, the maximum value of bond stress exists at

B A Bar

k L >P- *

Fig. 3.(a) End A(b) End B

(c) A from A

(d) At from A.

11.202. The ratio of coefficient of linear expansion of steel to that of concrete is roughly(a) 1.0 (b) 1.71(c) 1.41 (d) 1.19.

11.203. When e is the shrinkage strain, C is the creep coefficient, m is the modular ratio, / is the original prestress in concrete, Ec is the Young's modulus of elasticity, then the combined effect of creep and shrinkage would be equal to(a) Ec + (1 - C)fm(b) Ec + (C - 1 )mf(c) Ec + (Cm - 1)(,d) (C - 1) Ec + mf.

11.204. The working stress of concrete in tension is 0.6 N/mm2. The moment taken by a 200 mm x 400 mm concrete beam will be(a) 6.4 x 106 N-mm(b) 3.2 x 106 N-mm(c) 3.2 x 104 N-mm(d) 1.6 x 104 N-mm.

11.205. Minimum shear reinforcement in beams is

()

(c)

0.5 bd

fy 0.85bd

(b)

(d)

OAbd

fy0.87 bd

/* 'fy11.206. In a single reinforced beam,

subjected to shear force F, if d is the depth and b is the width of the section, and L is the lever arm, then maximum shear stress is given by

() (b) 6

(c)

bx d F

L bd id)

6 bd2 FL bd2 '

11.58 Civil Engineering (Objective Type)11.207. As compared to plain bars, the

perm issible bond stress for deformed bars is more by about(a) 5% (b) 10%(c) 25% (d) 40%.

11.208. Every reinforcing bar is extended beyond the point it is no longer required for bearing stress, by a distance equal to(fl) 4 diameters(b) 6 diameters(c) 12 diameters(d) 40 diameters.

11.209. When ck is the characteristic compressive strength of concrete in N/mm2, the flexural strength of concrete is given by

(fl)1

(c)

(b) (FdO3/2

(d) 1

11.210. In order that the cost of web reinforcements be minimum, the angle of inclination of web reinforcement should be(fl) 30 to horizontal(b) 2iy2 to horizontal(c) 60 to horizontal (rf) 67y2 to horizontal.

11.211. The coefficient of linear expansion of steel is(fl) 0.0098 cm/C(b) 0.00098 cm/C(c) 0.000098 cm/C(d) 0.0000098 cm/C.

11.212. For reinforced brick work, themodular ratio is generally taken is (fl)15 (6)18(c) 20 (d) 40.

11.213. In case of bridge slabs, the amountof transverse reinforcement i s .....percent of grass concrete area.(fl) 0.1 (b) 0.3

(c) 0.6 (d) 0.88.11.214. The effective span in case of slabs

continous over several beams and monolithically cast with them, is (fl) clear distance between supports(b) average distance betw een

supports(c) clear distance betw een

supports, plus effective depth of beam

(d) clear distance betw eensupports, plus one and a half times the effective depth of beams.

11.215. In case of a continuous beamextending over a number of spans,the maximum sagging momentnear the middle of end span forsuperimposed load is

WL WL() (fe)

(0

8WL

(d)

10WL

24 v" 7 48 '11.216. If W is the weight of hammer, H is

the fall of hammer in metres, P is the weight of pile (kg), S is the average penetration per blow in metres, then the total capacity of pile driven by a drop hammer is given by

W r ^ r O) W?

(c)

' >WH

1 +(d)

1+ s ls

WHS

1 + -w ) S,11.217. The breadth of the rib of a T-beam

should not be less than(a) one-sixth the depth of rib (.b) one-fourth the depth of rib(c) one-third the depth of rib(d) one-half the depth of rib.

RCC Structure Design 11.59

slabs is and m, is sports ween

weendepth

ween a half ?th of

beam spans, )ment an for

r, H is is, P is is the ow in city of mer is

-beam

ibrib

ibb.

11.218. The minimum tensile reinforcement in a beam is not less than(a) 0.3 percent of the gross cross-

sectional area of the beam(b) 1 percent of the gross cross-

sectional area of the beam(c) 3 percent of the gross cross-

sectional area of the beam(d) 10 percent of the gross cross-

sectional area of the beam.11.219. The depth of foundation below

ground level is usually calculated by the Rankine's formula, where the depth of foundation h (metres), is given by the relation :(p is the pressure in kg/m2 on the soil, W is the unit weight of soil in kg/m3 and is the angle of repose)

()/! = p 1 + sin2 (|)w 1 - sin2 (j)

w 1 - sin2 P 1 + sin2 (j)

P 1 - sin2 (j)w 1 + sin2

11.60 Civil Engineering (Objective Type)maximum tehsile stress in steel and a b is the maximum compressive stress in concrete and m is the modular ratio, then the neutral axis coefficient, N is given by

(a) N = - m (b) N: a . , as t^ c bm + a c.ctsf cb

(c) N = - (d) N = - 1

'- cb v cb

11.224. Partial safety factor on concrete stresses is(a) 1.25 (6) 1.33(c) 1.5 (d) 1.67.

11.225. The cross-sectional area of reinforcement in a R.C.C. columns as per IS-456 shall not be(a) less than 0.8 percent(b) more than 6 percent(c) more than 8 percent(d) less than 10 percent.

11.226. In the lim it state method ofconcrete design, the maximum com pressive strain in axial compression in concrete is taken as (a) 0.0035 (b) 0.002(c) 0.035 (d) 0.002.

11.227. The anchorage value of a bend (diameter ) of 90 is(fl) 4

RCC Structure Design 11.61I

ire of concrete

strength of the

ssive strength

ngth of the

: strength of

of the metal mm shall not area of the

>6 Ag10 Ag.of design the >r concrete is

sile strenght h of concrete

- column in s. Four bars er and four meter. The is 6 mm. The 11 be kept as

mm mm.

in designed method the for load

160rL

11.236. The lateral ties in a reinforced concrete rectangular column under axial compression are used to(fl) avoid the buckling of the

longitudinal steel under compression

(b) provide adequate shear capacity

(c) provide adequate confinement to concrete

(d) reduce the axial deformation of the column.

11.237. For the design of R.C. columns, acolumn is treated as short one if the ratio of effective length of its least lateral dimension is less than (fl) 20 (b) 16(c) 12 (d) 8.

11.238. Corner steel is provided in slab (fl) to resist the bending moment

at the corner(b) to make the slab sufficiently

rigid(c) to resist torsional moment(d) to prevent displacem ent of

corners.11.239. W hich one of the follow ing

conditions, both elastic end plastic methods of analysis of indeterminate structures have to satisfy?(a) Yield condition(b) Mechanism condition(c) Equilibrium(d) Compatibility of deformation.

11.240. To take care of reversible shear in an R.C.C. beam, it is advisable to use(fl) only vertical stirrups (b) vertical stirrups in association

with cranked reforcement.

(c) only cranked reinforcement(d) a combination of vertical and

inclined stirrups.11.241. The maximum unsupported length

between end restraints for a R.C. column is(a) 12 tim es the least interal

dimension(b) 15 tim es the least interal

dimension(c) 30 tim es the least lateral

dimension(d) 60 tim es the least interal

dimension.11.242. In the collapse load method of

designing a structure, the collapse is said to taken place when(fl) there is excessive deflection(b) yield stress is exceeded first at

a section(c) elastic instability develops(id) the structure degenerates into

a mechanism.If K is the neutral axis constant for a singly reinforced beam, the lever arm factor is given by

11.243.

/ \ * KT

/ \ i K Cc) 1 - 6

0b )i+

(d) 1 +

K3K

11.244. In the suspended span of a double cantilever bridge, the depth of the suspended beam is increased towards its ends for the purpose (fl) providing strength(b) deflection control(c) aesthetics(d) crack prevention.

11.245. For bar in tension, a standard hook has a anchorage equivalent to a straight length of(fl) 8 (b) 12 (c) 16 (|> (d) 24 .

160r

11.62 Civil Engineering (Objective Type)11.246. The sheap strength of an RCC

beam without web reinforcementis(a) zero (b) xjbd2(c) xcbd (d) x, jbd.

where t . is allowable shear strength of concrete, and j is lever arm factor

11.247. The top reinforcem ent at the support section of a continous beam shall be extended from either face of the column upto a distance equal to(a) effective span/3(b) effective span/6(c) effective span/5(d) effective span/8.

11.248. If (j) = nom inal diam eter of reinforcing bar, f s = compressive stress in the bar and f bd = design bond stress of concrete the anchorage length Lfl of straight bar in compression is equal to

flange for the cross-section shown in Fig. 5

( ) K =M.fb d

< * ) L = s

2 fb d

(c) L = sr f b d

( d ) K =V s

4 fb d

- 1000 -

600

11.249. The failure criteria used for concrete under compression in reinforced concrete beams and columns is(a) maximum principal stress

theory(b) maximum principal strain

theory(c) maximum shear stress theory(d) maximum distortion strain

energy theory.11.250. An isolated T-beam is used as a

w alkw ay the beam is sim ply supported with an effective span of 6 m. The effective width of

K300*f350H

Fig. 5.(a) 900 mm (b) 1000 mm(c) 1250 mm (d) 2200 mm.

11.251. If the bond stress developed in reinforced concrete beam is more than the permissible value, it can be brought down by increasing

1. depth of beam2. diameter of bars3. number of bars

Of these, the correct answers are(a) 1 and 2 only(b) 2 and 3 only(c) 1 and 3 only(d) 1, 2 and 3.

11.252. The relation between split tensile strength of concrete (fct) and crushing strength (fck) is

(/x2, M y = otyCo/x2(c) = a x c d /x 2, = a (o /y 2(d) M = Mv = a x coA'2.

11.254. Assertion (A) : W eepholes are provided in retaining walls Reasons (R) : Weepholes facilitate ventilation of these

RCC Structure Design 11.631 shov.T

red in more it can ising

rs are

ensileand

Stating s for ? areyv-y2

are

tate

(a) Both (A) and (R) are true and (R) is the correct explanationof (A)

(b) Both (A) and (R) are 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.

11.255. Assertion (A) : In a R.C.C. beam, the minimum tensile reinforcement must not be less than 0.3% percent when using plain bars.Reason (R) : In a RCC beam, the maximum area of tension reinforce-ment should not exceed 4 percent.Of these(a) Both (A) and (R) are true and

(R) is the correct explanation of (A)

(b) Both (A) and (R) are 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.

11.256. The span to depth ratio limit is specified in IS : 456-1978 for the reinforced concrete beams, in order to ensure that the(a) tensile crack width is below a

limit(b) shear failure is avoided(c) stress in the tension

reinforcement is less than the allowable value

(d) deflection of the beam is below a limiting value.

11.257. The minimum reinforcement of steel of grade Fe 415 in either direction of a slab is given by(a) 0 .2%(b) 0.12%(c) 0.15%

(d) 0.18% of gross concrete area.11.258. The effective width of a reinforced

concrete T-beam flange under compression, according to IS : 456- 19878 (given I0 is the distance betw een the adjacent zero moment point, b is the breadth of the rib and D is the thickness of the flange) is

(a) +b+6D6In

(C) ~6 + 6D

(b) b + 6D

(d )| + b.

11.259. The limiting depth of neutral axis for a rectangular beam reinforced with Fe 415 grade steel is(a) 0.43 d (b) 0.46 d (c) 0.48 d (d) 0.53 d.

11.260. If 'w' is the u.d.l. are a circular slab of Radius 'R' is freely supported at edges, then the radial moment at the middle of the slab will be

(fl)

(c)

WR_16

5WR216

(b)

{d)

3WR16

7WR216

11.261. When a pile of length 'L' carrying u.d.l. 'w' per unit length is suspended at two points then the maximum bending moment at the points of suspension will be

(fl)

(c)

WL216

WL2

(b)

(d)

WL247

WL290 118

11.262. The length of lap for reinforcement bars in compression shall not be less than

(fl) M .3Sh

or 24 whichever is less

11.64 Civil Engineering (Objective Type)

(b)

(c)

(d)

3S

f/.-3Sb

f fc5Sh

or 24 cj> whichever is more

or 30 whichever is less

or 30 (|) whichever is more.

(d)

(j) .for 24 (|> w hichever is

(c)

greater

RCC Structure Design 11.65ANSWERS

11.1. (a) 11.2. (d) 11.3. (d) 11.4. (d) 11.5. (c) 11.6. (a) 11.7. c)11.8. (d) 11.9. (c) 11.10. (d) 11.11. (b) 11.12. id) 11.13. (b) 11.14. c)

11.15. (d) 11.16. (b) 11.17. id) 11.18. ib) 11.19. (c) 11.20. (c) 11.21. )11.22. (c) 11.23. (d) 11.24. (c) 11.25. (c) 11.26. (b) 11.27. (c) 11.28. d)11.29. (c) 11.30. () 11.31. (c) 11.32. (b) 11.33. (c) 11.34. (d) 11.35. d)11.36. (a) 11.37. (d) 11.38. () 11.39. (c) 11.40. (b) 11.41. (b) 11.42. a)11.43. id) 11.44. (b) 11.45. (c) 11.46. (d) 11.47. (a) 11.48. (b) 11.49. a)

11.50. () 11.51. (d) 11.52. (a) 11.53. (d) 11.54. (b) 11.55. ib) 11.56. d)11.57. () 11.58. (a) 11.59. (b) 11.60. (b) 11.61. () 11.62. (c) 11.63. d)

11.64. (b) 11.65. (0 11.66. (d) 11.67. id) 11.68. (c) 11.69. (c) 11.70. n)11.71. (c) 11.72. () 11.73. (b) 11.74. () 11.75. () 11.76. (b) 11.77. c)11.78. (c) 11.79. (b) 11.80. (c) 11.81. () 11.82. (c) 11.83. (a) 11.84. d)11.85. (d) 11.86. (d) 11.87. (b) 11.88. (b) 11.89. (d) 11.90. (b) 11.91. c)11.92. (d) 11.93. (d) 11.94. (d) 11.95. (b) 11.96. (d) 11.97. (c) 11.98. c)11.99. () 11.100. (c) 11.101. (d) 11.102. (c) 11.103. (c) 11.104. (d) 11.105. b)

11.106. (c) 11.107. {a) 11.108. (d) 11.109. (c) 11.110. (c) 11.111. (d) 11.112. c)11.113. (d) 11.114. (d) 11.115. (c) 11.116. (d) 11.117. (c) 11.118. (c) 11.119. d)11.120. (c) 11.121. (c) 11.122. (c) 11.123. (c) 11.124. (d) 11.125. (c) 11.126. b)11.127. (d) 11.128. (b) 11.129. (d) 11.130. (d) 11.131. (d) 11.132. (c) 11.133. b)11.134. (d) 11.135. (a) 11.136. id) 11.137. (d) 11.138. (c) 11.139. (d) 11.140. c)11.141. (c) 11.142. (d) 11.143. (c) 11.144. id) 11.145. (b) 11.146. (c) 11.147. d)11.148. (d) 11.149. (d) 11.150. (b) 11.151. (b) 11.152. (d) 11.153. (c) 11.154. d)11.155. (d) 11.156. (d) 11.157. (d) 11.158. (c) 11.159. (d) 11.160. (c) 11.161. c)11.162. (a) 11.163. () 11.164. (c) 11.165. (a) 11.166. (d) 11.167. (d) 11.168. b)11.169. (d) 11.170. (d) 11.171. (c) 11.172. (d) 11.173. (d) 11.174. (c) 11.175. b)11.176. (d) 11.177. (a) 11.178. (d) 11.179. (c) 11.180. (d) 11.181. (d) 11.182. d)11.183. (a) 11.184. (d) 11.185. (d) 11.186. (b) 11.187. (a) 11.188. (b) 11.189. c)11.190. (a) 11.191. ib) 11.192. (d) 11.193. (d) 11.194. (d) 11.195. (c) 11.196. b)11.197. () 11.198. (d) 11.199. (d) 11.200. (d) 11.201. (a) 11.202. (d) 11.203. b)11.204. (b) 11.205. (b) 11.206. (a) 11.207. (c) 11.208. (d) 11.209. (fl) 11.210. d)11.211. (d) 11.212. (d) 11.213. (b) 11.214. () 11.215. (b) 11.216. (c) 11.217. c)11.218. () 11.219. (d) 11.220. (a) 11.221. (c) 11.222. () 11.223. (d) 11.224. c)

11.66 Civil Engineering (Objective Type)11.225. (6) 11.226. (6) 11.227. (c) 11.228. (b) 11.229. (b) 11.230. (c) 11.231. (?)11.232. (d) 11.233. (b) 11.234. (b) 11.235. (c) 11.236. (fl) 11.237. (c) 11.238. (c)11.239. (d) 11.240. (d) 11.241. (d) 11.242. (d) 11.243. (fl) 11.244. (fl) 11.245. (fl)11.246. (c) 11.247. (c) 11.248. (d) 11.249. (fl) 11.250. (fl) 11.251. (c) 11.252. (b)11.253. (c) 11.254. (fl) 11.255. (b) 11.256. (fl) 11.257. (b) 11.258. (fl) 11.259. (c)11.260. (b) 11.261. (b) 11.262. {b) 11.263. (c) 11.264. (c) 11.265.(6) 11.266.(6)11.267. (6) 11.268. (d)