DESIGN OF CONCRETE STRUCTURES - I Multiple Choice Questions (MCQ)
DESIGN OF CONCRETE STRUCTURES - I MCQ
Unit 1: Introduction
1) The maximum compressive strain in concrete in axial compression is taken as
A. 0.001
B. 0.002
C. 0.003
D. 0.040
ANSWER: B
2) The flexural strength of concrete is given by
A. 0.6√fck
B. 0.7√fck
C. 0.5√fck
D. 0.8√fck
ANSWER: B
3) Tolerance on placing the reinforcement for effective depths 200 mm or less is
A. +/-5mm
B. +/-6mm
C. +/-8mm
D. +/-10mm
ANSWER: D
4) Tolerance on placing the reinforcement for effective depths more than 200 mm is
A. +/-5mm
B. +/-6mm
C. +/-8mm
D. +/-10mm
ANSWER: A
5) The minimum frequency of sampling of concrete of each grade for 1-5m3 shall be
A. 1
B. 2
C. 3
D. 4
ANSWER: A
6) The minimum frequency of sampling of concrete of each grade for 51m^3 and above shall be……samples.
A. 4 + one additional for each 50m3
B. 5 + one additional for each 50m3
C. 6 + one additional for each 50m3
D. 4 - one additional for each 50m3
ANSWER: A
7) The effective span of member that is not built integrally with its supports Shall be taken as .....
A. Clearspan plus effective depth of slab or beam
B. Center to center supports whichever is
C. a or b whichever is less
D. a or b whichever is more
ANSWER: A
8) The basic value of span to depth ratio for span up 10 m for cantilever beam is…………………
A. 7
B. 20
C. 26
D. 16
ANSWER:C
9) The design strength of steel in limit state design is …………
A. fy/1.5
B. 0.87 fy
C. fy/0.87
D. 0.87/1.5fy
ANSWER: B
10) Give four reasons to justify the design of structures by limit state method.
A. Concept of separate partial safety factors of loads of different combinations in the two limit state methods.
B. Concept of separate partial safety factors of materials depending on their quality control during preparation. Thus, gm for concrete is 1.5 and the same for steel is 1.15. This is more logical than one arbitrary value in the name of safety factor.
C. A structure designed by employing limit state method of collapse and checked for other limit states will ensure the strength and stability requirements at the collapse under the design loads and also deflection and cracking at the limit state of serviceability. This will help to achieve the structure with acceptable probabilities that the structure will not become unfit for the use for which it is intended.
D. The stress block represents in a more realistic manner when the structure is at the collapsing stage (limit state of collapse) subjected to design loads.
E. All of these
ANSWER: E
11) The modulus of elasticity of concrete can be assumed as follows:
A. Ec= 5000 √(fck)
B. Ec= 500 √(fck)
C. Ec= 7000 √(fck)
D. Ec= 1500 √(fck)
ANSWER: A
12) The partial factor of safety in limit state of serviceability of steel is
A. 1.15
B. 1.00
C. 1.55
D. 1.60
ANSWER: A
13) The maximum strain in the tension reinforcement in the section at failure shall not be less than
A. 0.002 + (0:87 fy/Es)
B. 0.0035 + (0.87 fy/Es)
C. 0.0035 +(fy/1.l5Es)
D. 0.002 + (0.85 Es/fy)
ANSWER: A
14) For avoiding the limit state of collapse, the safety of RC structures is checked for appropriate combination of dead load (DL), imposed load (IL), wind load (WL), and earth quake load (EL), which of the following load combinations are not considered?
A. 0.9 DL+ 1.5 WL
B. 1.5 DL + 1.5 WL
C. 1.5 DL + 1.5 WL + 1.5 EL
D. 1.2 DL + 1.2 IL + 1.2 WL
ANSWER:C
15) The purpose of providing certain minimum cover to reinforcements is to
A. have better bond between steel and concrete
B. to prevent corrosion, fire hazard to steel and other adverse environmental effects.
C. Both A and B
D. None
ANSWER:C
16) In a random sampling procedure for cube strength of concrete, one sample consists of X number of specimens. These specimens are tested at 28 days and average strength of these X specimens is considered as test results of the sample, provided the individual variation in the strength of specimens is not more than ±...Y percent of the average strength. The values of X and Y as per IS: 456 - 2000 are respectively
A. 4 and 10
B. 3 and 10
C. 3 and 15
D. 4 and 15
ANSWER:C
17) The stress strain curve of the concrete as per IS 456 is
A. a perfect straight line up to failure
B. straight line up to 0.002 strain value and then parabolic up to failure
C. parabolic up to 0.002 strain value and then uniform up to failure
D. linear up to 0.002 strain and uniform up to failure
ANSWER:C
18) In limit state design of concrete for flexure, the area of stress block is taken as
A. 0.36 fck Xu
B. 0.446 fck Xu
C. 0.45 fck Xu
D. 0.57 fck Xu
ANSWER:C
19) Minimum tension steel in RC beam needs to be provided to
A. prevent sudden failure
B. arrest crack width
C. control excessive deflection
D. prevent surface hair cracks
ANSWER: A
20) If a continuous beam having an effective length as 18 m and a modification factor as 1.2 then its depth is ………
A. 0.576 m
B. 0.567 m
C. 1.245 m
D. 0.692 m
ANSWER: A
21) The maximum Shrinkage Strain is Given as
A. 0.0003
B. 0.0035
C. 0.416
D. 0.446
ANSWER: A
22) Creep coefficient at 7 days loading is
A. 2.2
B. 1.6
C. 1.1
D. 1.15
ANSWER: A
23) Match Group 1 with group 2
Group 1 | Group 2 |
1) Cylinder splitting | a) Workability of concrete |
2) Vee- bee test | b) Direct tensile test |
3) Surface area test | c) Bond between concrete and steel |
4) Fineness modulus test | d) Fineness of cement |
5) Pull out test |
|
A. 1-b, 2-a, 3-d, 4-d, 5-c
B. 1-c, 2-d, 3-a, 4-d, 5-c
C. 1-c, 2-d, 3-a, 4-d, 5-b
D. 1-c, 2-b, 3-d, 4-d, 5-b
ANSWER: A
24) For a particularly aggressive environment, such as the ‘severe’ category in Table 3, the assessed surface width of cracks should not in general, exceed…………
A. 0.1 mm
B. 0.3 mm
C. 0.2 mm
D. 0.01 mm
ANSWER: A
25) If 'l' is the effective span in metres and 'D' is overall depth of the section in mm, the structure may be accepted after 24-hour load test, provided the maximum deflection in mm is less than ____
A. 10l2/D
B. 20 l2/D
C. 40 l2/D
D. 30 l2/D
ANSWER:C
UNIT 2: Design of Slab
1) The diameter of reinforcing bar shall not exceed _________ of the total thickness of the slab.
A. 1/6
B. 1/8
C. 1/3
D. 1/4
ANSWER: B
2) For two-way slab with shorter span up to 3.5 m with Tor steel for the span to overall depth ratio for continuous slab.
A. 30
B. 40
C. 28
D. 32
ANSWER: D
3) In case of 2-way slab, the limiting deflection of slab is
A. Primarily a function of long span
B. Primarily a function of short span
C. Independent of long span and short span
D. Dependent on both long span and short span
ANSWER: B
4) For two-way slab for max. B.M. per unit width in a slab in longer direction is…………….
A. αy wlx2
B. αx wly2
C. αx wlx2
D. αx wly2
ANSWER: A
5) The mild steel reinforcement in either direction in slab shall Not be less than………… % of the area.
A. 0.1
B. 0.15
C. 0.2
D. 0.25
ANSWER: B
6) The high strength deformed bars reinforcement in either direction in slab shall Not be less than………… % of the area.
A. 0.1
B. 0.15
C. 0.12
D. 0.25
ANSWER: C
7) The main reinforcement of RC slab consists of 10 mm bars @ 10 cm spacing. It is desired to replace 10 mm bars by 12 mm bars and then the spacing of 12 mm bars should be
A. 12 cm
B. 14 cm
C. 14.40 cm
D. 16 cm
ANSWER: C
8) In two way restrained slab the middle strip being ______________ times width.
A. 1/8
B. 3/4
C. 1/4
D. ½
ANSWER: B
9) For two-way slab with shorter span up to 3.5 m with Mild steel reinforcement for the span to overall depth ratio for continuous slab is ---------------
A. 30
B. 40
C. 28
D. 32
ANSWER: B
10) For two-way slab with shorter span up to 3.5 m with Mild steel reinforcement for the span to overall depth ratio for simply supported slab is ---------------
A. 35
B. 40
C. 28
D. 32
ANSWER: A
11) For two-way slab with shorter span up to 3.5 m with Tor steel for the span to overall depth ratio for simply supported slab is ---------------
A. 35
B. 40
C. 28
D. 32
ANSWER: C
12) Tension reinforcement provided at mid-span in middle strip of two-way slab restrained shall extend in lower part of slab to within ___________ L of a continuous edge.
A. 0.2
B. 0.25
C. 0.15
D. 0.3
ANSWER: B
13) Tension reinforcement provided at mid-span in middle strip of two-way slab restrained shall extend in lower part of slab to within ___________ L of a discontinuous edge.
A. 0.2
B. 0.25
C. 0.15
D. 0.3
ANSWER: C
14) ln a two way restrained slab torsion steel is provided at
A. Top
B. bottom
C. 'a' and 'b'
D. none
ANSWER: C
15) In a slab 12 mm diameter bars are to be provided at 150 mm center to center, due to non-availability the diameter of bars is to be changed to 16 mm the new spacing would be
A. 266.66 mm
B. 84.37 mm
C. 300 mm
D. 450 mm
ANSWER: A
16) A simply supported slab of 10 m effective span, the minimum effective depth to satisfy the vertical deflection limits should be
A. 50 cm
B. 75 cm
C. 60 cm
D. 90 cm
ANSWER: A
17) The moment coefficients given in IS: 456-2000 for simply supported two-way slabs are based on
A. Rankine- Grashoff' s method
B. Westergaards method
C. Johansens yield line theory
D. Bernoulli’s theory
ANSWER: A
18) The bending moment coefficients given in IS:456 - 2000 for two-way slab is based on
A. Rankine- Grashoff's method
B. Westergaard's method
C. Johansen's yield line theory
D. plate theory
ANSWER: A
19) The minimum percentage of high yield strength deformed bars in RCC slabs is:
A. 0.4
B. 0.15
C. 0.12
D. 0.23
ANSWER:C
20) In a two-way slab lifting of corners occur due to________.
A. resultant shear force at the ends
B. torsional moment on the slab
C. resultant stress at the ends
D. unbalanced moment on the slab
ANSWER: B
21) As per IS: 456-2000, consider the following statements:
I. The modular ratio considered in the working stress method depends on the type of steel used.
II. There is an upper limit on the nominal shear stress in beams (even with shear reinforcement) due to the possibility of crushing of concrete in diagonal compression.
III. A rectangular slab whose length is equal to its width may not be a two-way slab for some support conditions.
The TRUE statements are
A. only I and II
B. only II and III
C. only I and III
D. I, II and III
ANSWER: A
22) The horizontal distance between parallel main reinforcement bars shall not be more than ------- of solid slab.
A. 3 d
B. 0.75 d
C. 5d
D. None of these
ANSWER: A
23) The horizontal distance between parallel reinforcement bars provided against shrinkage and temperature shall not be more than --------- of a solid slab.
A. 3 d
B. 0.75 d
C. 5d
D. None of these
ANSWER:C
24) The spacing between parallel main reinforcement of bars in solid slab shall not be more than -----.
A. 200 mm
B. 300 mm
C. 450 mm
D. 150 mm
ANSWER: B
25) The spacing between distribution reinforcement of bars in solid slab shall not be more than -------.
A. 200 mm
B. 300 mm
C. 450 mm
D. 150 mm
ANSWER:C
Unit 3: Limit State of Collapse (Flexure, Shear & Bond)
1) A beam having effective depth 450 mm having neutral axis depth as 0.53*d has neutral axis factor as……………………………….
a) 0.53
b) 238.5
c) 0.53d
d) 0.48
ANSWER: A
2) In LSM the characteristic load is defined as the mean load plus 'k' times the deviation. If the characteristic load is not to exceed only 5% times the expected life of the structure, the value of 'k; is
a) zero
b) 0.72
c) 1.65
d) none
ANSWER: C
3) Flexural strength of M25 concrete is ………….
a) 3.5 N/mm2
b) 35 N/mm2
c) 5.3 N/mm2
d) 53 N/mm2
ANSWER: A
4) The lever arm in Limit State is
a) d-0.446Xu
b) d-0.87Xu
c) d-0.146Xu
d) d-0.36Xu
ANSWER: A
5) The centroid of compressive force from the extreme compression fibre in limit state design lies at a distance of
a) 0.367Xu
b) 0.416Xu
c) 0.446Xu
d) o.57Xu
ANSWER: B
6) The effective span of member that is not built integrally with its supports Shall be taken as………….
a) Clear span plus effective depth of slab or beam
b) Center to center supports
c) a or b whichever is less
d) a or b whichever is more
ANSWER: C
7) The depth of the neutral axis is calculated from the known area of steel and it should be
a) less than 0.5 times the full depth of the beam
b) more than 0.5 times the effective depth of the beam
c) less than or equal to limiting value of the neutral axis depth
d) less than 0.43 times the effective depth of the beam
ANSWER: C
8) Particular grade of concrete and with lowering the grade of steel, the ptlim___________
a) increases
b) decreases
c) sometimes increases and sometimes decreases
d) remains constant
ANSWER: A
9) Which of the statements is correct?
a) xu,max/d is independent of grades of concrete and steel
b) xu,max/d is independent of grade of steel but changes with grade of steel
c) xu,max/d changes with the grade of concrete and steel
d) xu,max/d is independent of the grade of concrete and changes with the grade of steel
ANSWER: D
10) Compression reinforcement is provided when:
a) Some sections of a continuous beam with moving loads undergo change of sign of the bending moment which makes compression zone as tension zone,
b) the ductility requirement has to be satisfied,
c) the reduction of long term deflection is needed.
d) All of these
e) None of these
ANSWER: D
11) Maximum strains in an extreme fibre in concrete and in the tension reinforcement Fe-415 grade and Es = 2x 105 N/mm2 in a balanced section at limit state of flexure are respectively
a) 0.0035 and 0.0038
b) 0.002 and 0.0018
c) 0.0035 and 0.0041
d) 0.002 and 0.0031
ANSWER: A
12) The flexural strength of M30 concrete as per IS:456-2000 is
a) 3.83 MPa
b) 5.47 MPa
c) 21.23 MPa
d) 30.0 MPa
ANSWER: B
13) Assuming concrete below the neutral axis to be cracked, the shear stress across the depth of a singly-reinforced rectangular beam section
a) increases parabolically to the neutral axis and then drops suddenly to zero value.
b) increases parabolically to the neutral axis and then remains constant over the remaining depth.
c) increases linearly to the neutral axis and then remains constant up to the tension steel.
d) increases parabolically to the neutral axis and then remains constant up to the tension steel.
ANSWER:C
14) Limit state of serviceability for deflection including the effects due to creep, shrinkage and temperature occurring after erection of partition and application of finishes as applicable to floors and roofs is restricted to -----------
a) Span/150
b) Span/200
c) Span/250
d) Span/350
ANSWER: D
15) The modulus of elasticity of concrete can be assumed as follows:
a) Ec = 5000√fck
b) Ec = 7000√fck
c) Ec = 2000√fck
d) Ec = 6000√fck
ANSWER: A
Unit 4: Analysis and Design of Flanged Sections
1. Effective width of flange for T beam is ___________
A. (l0/6) + bw + 6 Df
B. (l0/3) + bw + 3 Df
C. (l0/12) + bw + 6 Df
D. (l0/12) + 6 bw + Df
ANSWER: A
2. Slenderness limit for beam to ensure lateral stability for simply supported or continuous beam shall be so proportioned that the clear distance between lateral restraints does not exceed …. b or……. b2/d whichever is less
A. 25, 100
B. 30, 90
C. 50, 50
D. 60, 250
ANSWER: D
3. Effective width in L beam is ___________
A. (l0/12) + bw + 3 Df
B. (l0/12) + 3bw + Df
C. (l0/6) + bw + 6 Df
D. (l0/12) + bw + 6Df
ANSWER: A
4. How is the deflection in RC beam controlled as per IS 456?
A. By using large aspect ratio
B. By using small modular ratio
C. By controlling span to depth ratio
D. By moderating water cement ratio
ANSWER:C
5. Effective width of flange will be either less or equal to the actual flange width, the main reason for this as depicted in IS 456 is:
A. Stress is more uniform near the web on either side compared to farther locations.
B. Nearer section are more effective than farther one's.
C. Slab will be in compression near the beam
D. None of the above
ANSWER:C
6. If the neutral axis lies in the flange, a T - beam can be treated as a rectangular beam of
A. bw x d
B. bf x D
C. bf x d
D. None of the above
ANSWER: B
7. In T-beams the web and flange are more effective in resisting
A. bending stress and shear stress respectively
B. shear stress and bending stress receptively
C. both bending and shear
D. None of the above
ANSWER: B
8. Basic values of span to effective depth ratios for spans up to 10 m for Cantilever, simply supported & Continuous elements is _______
A. 7, 20 & 26
B. 7, 26 & 20
C. 20, 26 & 7
D. 17, 26 & 20
ANSWER: A
9. Slenderness limit for beam to ensure lateral stability for a cantilever beam shall be so proportioned that the clear distance from the free end of the cantilever to the lateral restraint shall not exceed ……. b or……. b2/d whichever is less
A. 25, 100
B. 30, 90
C. 50, 50
D. 60, 250
ANSWER: A
10. 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
ANSWER: D
11. 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
ANSWER: D
12. 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
ANSWER:C
13. The width of the flange of a T-beam should be less than
A. one-third of the effective span of the T-beam
B. distance between the centres of T-beam
C. breadth of the rib plus twelve times the thickness of the slab
D. least of the above.
ANSWER: D
14. The width of the flange of a T-beam, which may be considered to act effectively with the rib depends upon
A. breadth of the rib.
B. overall thickness of the rib
C. center to centre distance between T-beams
D. span of the T-beam
E. all the above.
ANSWER: E
15. 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
Unit 5: Design of Continuous Beam
1. Effective span of continuous beam, if the width of support is greater than 1/12 th of clear span or 600 mm whichever is less for end span with one end free and other continuous shall be ----------
A. Clearspan + d/2
B. Clearspan + d
C. Clearspan + ½ width of discontinuous support
D. Clearspan + d/2 or Clear span + ½ width of discontinuous support whichever is less.
ANSWER: D
2. The basic value of span to depth ratio for span up 10 m for Continuous beam is…………………
A. 7
B. 20
C. 26
D. 16
ANSWER: C
3. Effective span of continuous beam, if the width of support is greater than 1/12 of clear span or 600 mm whichever is less for end span with one end fixed and the other continuous or for intermediate spans shall be ………….
A. Clearspan +d/2
B. Clearspan
C. Clearspan +1/2 width of discontinuous support
D. Clear span +d/2 or clear span +1/2 width of discontinuous support whichever is less.
ANSWER: B
4. The unit weights of various materials used for building construction are given in ---------------
A. IS 456-2000
B. IS 875(Part-1)-1987
C. IS 12119-1987
D. IS 5816-1999
ANSWER: B
5. For maximum sagging B.M.at support in a continuous RC beam, Live Load should be placed on __
A. Spans adjacent to support plus alternate spans
B. All the spans except the spans adjacent to the support
C. Spans next to adjacent spans of the support plus alternate spans
D. Spans adjacent to supports only
ANSWER:C
6. In limit state method of concrete structures, the strain distribution is assumed to be
A. parabolic
B. nonlinear
C. linear
D. parabolic and rectangular
ANSWER: B
7. From limiting deflection point of view, use of high strength steel in RC beam results in
A. Reduction in depth
B. No change in depth
C. Increase in depth
D. Increase in width
ANSWER: C
8. A continuous beam deemed to be deep beam if the ration of effective span to overall depth is,
A. 2.5
B. 2.0
C. less than 2
D. less than 2.5
ANSWER: A
9. The maximum working load that a structure has to withstand and for which it is to be designed is called as
A. ultimate load
B. characteristic load
C. factored load
D. none of the above
ANSWER: A
10. The shear coefficient of continuous beam of uniform c/s which supports UDL over three or more spans which do not differ by more than 15% of the long span are ____________ for D.L. and ____________ for L.L. at all other interior supports.
A. 0.4, 0.45
B. 0.6, 0.6
C. 0.55, 0.6
D. 0.5, 0.6
ANSWER: D
11. The shear coefficient of continuous beam of uniform c/s which supports UDL over three or more spans which do not differ by more than 15% of the long span are ____________ for D.L. and ____________ for L.L. at end supports.
A. 0.4, 0.45
B. 0.6, 0.6
C. 0.55, 0.6
D. 0.5, 0.6
ANSWER: A
12. Slenderness limit for beam to ensure lateral stability for simply supported or continuous beams shall be so proportional that the clear difference for the lateral restraining does not exceed _________ b or _________ b2/d whichever is less.
A. 30, 90
B. 60, 250
C. 25, 100
D. 50, 50
ANSWER: B
13. In case of continuous beams, the distance between the points of zero moment, may be obtained as (where l is the effective span).
A. 0.5 l
B. 0.6 l
C. 0.7 l
D. 0.8 l
ANSWER:C
14. The effective and actual lengths of a cantilever are same if continuous at the support,
A. unstrained against torsion at the support and free at the end
B. with partial restraint against torsion of the support and free at the end
C. restrained against torsion at the support and free at the end
D. none of the these.
ANSWER:C
15. Pick up the correct statement from the following:
A. The effective span of a simply supported beam is clear span plus its effective depth or centre to centre of supports whichever is less
B. The effective span of a simply supported slab is clear span plus its effective depth or centre to centre of supports whichever is less
C. The effective span of a continuous beam or slab is the clear span plus its effective depth or centre to centre of supports whichever is less, provided the width of the support is less than ½ of clear span
D. For spans with roller or rocker bearing, the effective span is the distance between the centres of bearings
E. All the above.
ANSWER: E
UNIT 6: Beams subjected to Combined Bending, Torsion & Shear
1. For member subjected to bending and torsion two legged closed hoops enclosing the corner longitudinal bars shall have an area of cross-section Asv given by,
A. Asv = [(Tu.Sv/b1d1(0.47fy)] + [Vu.Su/2.5d1(0.47fy)]
B. Asv = (Tu.Sv/b1d1(0.87fy) + Vu Tu)
C. Asv(Tu.Sv/b1d1(0.85fy)
D. Asv = [(Tu.Sv/b1d1(0.87fy)] + [Vu.Su/2.5d1(0.87fy)]
ANSWER: D
2. Where depth of beam exceeds 750 mm the side face reinforcement shall be Provided along the two faces. The total area of such reinforcement shall not be Less than……... % of web area.
A. 0.1
B. 0.15
C. 0.2
D. 0.25
ANSWER: A
3. From limiting deflection point of view, use of high strength steel in RC beam results in_____
A. Reduction in depth
B. No change in depth
C. Increase in depth
D. Increase in width
ANSWER:C
4. For a longitudinal reinforcing bar in a column nominal cover shall in any case not be less than____
A. 40 mm
B. 20 mm
C. 50 mm
D. 15 mm
ANSWER: A
5. In the case of columns of minimum dimension of 200 mm or under, whose reinforcing bars do not exceed 12 mm, a nominal cover of -------- may be used.
A. 40 mm
B. 20 mm
C. 50 mm
D. 25 mm
ANSWER: D
6. At the limit state of collapse, an RC beam of section 300 mm × 600 mm, subjected to factored SF = 95 kN, factored torsional moment = 45 kN-m and factored B.M. = 115 kN-m. the equivalent shear force (Ve) is______
A. 335 kN
B. 300 kN
C. 354 kN
D. 68 kN
ANSWER: A
7. At the limit state of collapse, an RC beam of section 300 mm × 600 mm, subjected to factored SF = 95 kN, factored torsional moment = 45 kN-m and factored B.M. = 115 kN-m. The equivalent flexural moment (Meq) to designing longitudinal tension steel is______
A. 194.50 kN-m
B. 209 kN-m
C. 200 kN-m
D. 213 kN-m
ANSWER: A
8. At the limit state of collapse, an RC beam is subjected to factored SF = 20 kN, factored torsional moment = 9 kN-m and factored flexural moment = 200 kN-m. The beam is 300 mm wide and has a gross depth of 425 mm, with an effective cover of 25 mm. The equivalent shear force (Ve) is_____
A. 20 kN
B. 56 kN
C. 54 kN
D. 68 kN
ANSWER: D
9. At the limit state of collapse, an RC beam is subjected to factored SF = 20 kN, factored torsional moment = 9 kN-m and factored flexural moment = 200 kN-m. The beam is 300 mm wide and has a gross depth of 425 mm, with an effective cover of 25 mm. The equivalent flexural moment (Meq) to designing longitudinal tension steel is______
A. 187 kN-m
B. 209 kN-m
C. 200 kN-m
D. 213 kN-m
ANSWER: D
10. The equivalent flexural moment Meq is calculated by using
A. Meq = Mu + Tu{(1+D/b)/1.5}
B. Meq = Mu + Tu{(1+D/b)/1.7}
C. Meq = Mu + Tu{(1-D/b)/1.7}
D. Meq = Mu + Tu{(1+b/D)/1.7}
ANSWER: B
11. As per IS 456: 2000, Equivalent shear, Ve shall be calculated from the formula:
A. Ve = Vu + {1.6 (Tu/b)}
B. Ve = Vu - {1.6 (Tu/b)}
C. Ve = Vu + {1.9 (Tu/b)}
D. Ve = Vu + {1.6 (Tu/d)}
ANSWER: A
UNIT 7: Columns
1. The diameter of the polygonal links or lateral ties shall not be less than
A. 6 mm
B. max of A and D
C. least of A and D
D. 1/4 diameter of larger longitudinal bar
ANSWER: D
2. The cross-sectional area of longitudinal reinforcement, shall be not more than ------- percent of the gross cross sectional area of the column.
A. 0.8
B. 6
C. 0.4
D. 1
ANSWER: B
3. The diameter of the polygonal links or lateral ties shell not be less than
A. 1/4 diameter of larger longitudinal bar.
B. 6 mm
C. Least of A and B
D. Max of A and B
ANSWER: A
4. In case of column minimum dimension of 200 mm under where reinforcement bars do not exceed 12 mm, a nominal cover of……..may be used
A. 20 mm
B. 25 mm
C. 30 mm
D. 45 mm
ANSWER: B
5. Which one of the following statements is correct?
A. maximum longitudinal reinforcement in an axially loaded short column is 6% of c/s
B. column with circular section are provided transverse reinforcement of helical type only
C. spacing of lateral ties cannot be more than 16 times the diameter of the tie bat
D. longitudinal reinforcement bar need not be in contact with lateral ties
ANSWER: A
6. The minimum number of longitudinal bars provided in a column shall be …………… in a circular column.
A. 6
B. 4
C. 8
D. 2
ANSWER: A
7. The minimum number of longitudinal bars provided in a column shall be …………… in a rectangular column.
A. 6
B. 4
C. 8
D. 2
ANSWER: B
8. Helical reinforcement in circular column is provided in terms of
A. Helix
B. Links
C. Stirrups
D. Ties
ANSWER: A
9. The cross-sectional area of longitudinal reinforcement, shall be not less than ------ percent of the gross cross sectional area of the column.
A. 0.8
B. 6
C. 0.4
D. 1
ANSWER: A
10. The minimum number of longitudinal bars provided in a column shall be four in rectangular columns and six in circular columns.
A. true
B. false
ANSWER: A
11. For longitudinal reinforcement in columns the bars shall not be less than -------- in diameter.
A. 12 mm
B. 16 mm
C. 20 mm
D. 10 mm
ANSWER: A
12. A reinforced concrete column having helical reinforcement shall have at least ----- bars of longitudinal reinforcement within the helical reinforcement.
A. Six
B. four
C. eight
D. twelve
ANSWER: A
13. Spacing of longitudinal bars measured along the periphery of the column shall not exceed ----- mm.
A. 300 mm
B. 250 mm
C. 450 mm
D. 150 mm
ANSWER: A
14. The effective length of a column in a reinforced concrete building frame, as per IS456:2000, is independent of the
A. frame type i.e., braced (no sway) or un-braced (with sway)
B. span of the beam
C. height of the column
D. loads acting on the frame
ANSWER: D
15. In an axially loaded column the maximum strain in concrete is not exceeding to
A. 0.002
B. 0.00035
C. 0.0003
D. 0.0035
ANSWER: A
16. The ratio of effective length to unsupported length of a column when effectively held in position in both ends, to restrained against rotation at one end is
A. 0.8
B. 0.65
C. 1.2
D. 1.0
ANSWER: A
17. The use of lateral ties in a column is
A. to keep main reinforcement in position
B. to take care of shear developing due to buckling
C. to give confinement to concrete in the core
D. to increase ductility to the column
ANSWER: C
18. The lateral ties in a reinforced column under pure axial compression are due to
A. to avoid buckling of the longitudinal reinforcement
B. to provide adequate shear capacity
C. provide adequate confinement to concrete
D. reduce the axial deformation to the column
ANSWER: A
19. The axial load carrying capacity of a column of a given material, cross sectional area and length is governed by
A. strength of its material only
B. its slenderness ratio only
C. its flexural rigidity only
D. both flexural rigidity and slenderness ratio
ANSWER: D
20. The factored load carrying capacity of a column of 300 mm x 600 mm size with minimum percentage of steel is (M20, Fe4l5)
A. 1840 kN
B. 180 kN
C. 1829 kN
D. None of the above
ANSWER: A
21. The ultimate load carrying capacity of a circular section of 300 mm diameter with helical reinforcement using one percentage of reinforcement and M20 concrete and Fe 415 grade steel is ------------
A. 360 kN
B. 1000 kN
C. 800 kN
D. d)none
ANSWER: C
22. The load carrying capacity of a helically reinforced column as compared to that of a tied column is about
A. 5% less
B. 10 % less
C. 5% more
D. 10 % more
ANSWER: C
23. A 5 m long square column is fixed at one end and hinged at the other end has minimum radius of gyration as 100 mm, its slenderness ratio is
A. 50 mm
B. 40 mm
C. 32.5 mm
D. 20 mm
ANSWER: B
24. What is the minimum eccentricity of the axial load for the column?
A. 20 mm
B. 10 mm
C. 16 mm
D. 12 mm
ANSWER: A
25. Recommended value of effective length for column which is effectively held in position at both ends & restrained against rotation at one end is _____
A. 0.8l
B. 1.00l
C. 0.85l
D. 0.65l
ANSWER: A
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