## Prestressed Concrete Structures MCQ Set 1

1. In general, a satisfactory design must ensure the achievement of an acceptable:

a) Life of structure

b) Curing

c) Design

d) Crack

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2. The limit states at which the structure ceases to function the most important among them is:

a) Strain

b) Deflection

c) Stress

d) Deformation

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3. The failure of one or more critical sections in:

a) Flexure

b) Breakage

c) Bondage

d) Prestress

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4. One of the criteria considered for ultimate limit state is:

a) Bursting of midspan

b) Bursting of endblock

c) Bursting of edge block

d) Bursting of middle block

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5. The bearing failure at which point is considered as criteria for ultimate limit state?

a) Bearing failure at edges

b) Bearing failure at midspan

c) Bearing failure at supports

d) Bending failure at edge

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6. The failure due to which member is considered as criteria for ultimate limit state:

a) Elastic instability of members

b) Elastic stability of members

c) Deformation of members

d) Relaxation of members

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7. The limit state of collapse may be attained due to:

a) Friction

b) Attraction

c) Ductility

d) Vibrations

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8. The structure may be rendered unfit due to:

a) Collapse limit states

b) Nature limit states

c) Serviceability limit states

d) Loaded limit states

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9. The excessive deflection or displacement, adversely affects the:

a) Finishes

b) Edges

c) Paintings

d) Beam detailing

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10. The excessive local damage resulting in cracking impairs the:

a) Efficiency

b) Deficiency

c) Capacity

d) Dead loads

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## Prestressed Concrete Structures MCQ Set 2

1. In the case of composite members, deflections are computed by taking into account the different stages of:

a) Tension

b) Loading

c) Ranging

d) Hogging

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2. The initial deflection is due to:

a) Self weight

b) Cross section

c) Beam weight

d) Foundation

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3. The live load deflection is always estimated using:

a) Beam sections

b) Composite sections

c) Bent sections

d) Rolled sections

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4. When the modulus of elasticity of the precast and insitu cast concrete are different the flexural rigidity is worked out by:

a) First moment of area

b) Second moment of area

c) Limit states

d) Composite beam

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5. One of the knowledge required for planning of any structural component is:

a) Seismic nature of terrain

b) Regional nature of terrain

c) Wind nature of terrain

d) Loads

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6. In general appropriate technology must necessarily involve the prevailing:

a) Structures

b) Infastructure

c) Codes

d) Books

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7. The factors which influence the cost of a bridge are:

a) Method of erection

b) Length of beam

c) Cost of water

d) Testing of materials

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8. For spans less than 35m, SSB beams are?

a) Costly

b) Cheapest

c) Zero

d) Constant

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9. Which are more expensive than continuous beams of unequal spans?

a) Portals

b) Hinges

c) Layers

d) Arches

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10. In the early 1960, based on which analysis have reported the variation of the cost of bridge decks:

a) Rigorous computations analysis

b) Tension analysis

c) Strain analysis

d) Stress analysis

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## Prestressed Concrete Structures MCQ Set 3

1. Which knowledge is essential to comply with the limit state of deflection?

a) Bending moment

b) Shear stress

c) Shear torsion

d) Load deformation

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2. The tensile stress of about which limit are invisible to naked eye?

a) 5n/mm^{2}

b) 6n/mm^{2}

c) 3n/mm^{2}

d) 10n/mm^{2}

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^{2}which is invisible to the naked eye, on further loading cracks are first visible at flexural tensile stresses between 3.5 and 7n/mm

^{2}the higher values generally correspond to beams with well bonded steel distributed close to the tensile face as in the case of pretensioned members.

3. The load deflection curve is approximately linear up to stage of:

a) Invisible cracking

b) Visible cracking

c) Invisible deflection

d) Visible deflection

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4. In post cracking stage, the behavior of the beam is similar to:

a) Prestressed concrete members

b) Reinforced concrete members

c) Chemical concrete members

d) Biological concrete members

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5. The deflections of cracked structural concrete members may be estimated by:

a) Unilinear method

b) Matrix method

c) Step method

d) Elongation method

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6. Which of the following equation is used to compute deflections of unilinear method?

a) βL^{2}e/E_{c}I_{t}

b) βL^{2}M/E_{c}I_{t}

c) βL^{3}/E_{c}R

d) βL^{4}/E_{c}R_{t}

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^{2}M/E

_{c}I

_{t}, a = maximum deflection, L = effective span, M = maximum moment in the beam, E

_{c}= modulus of elasticity of concrete, I

_{c}= second moment of area equivalent cracked moment, β = constant.

7. The actual load deflection behavior is possible by assuming:

a) Bilinear moment curvature

b) Multilinear moment

c) Trilinear moment curvature

d) Bin linear moment curvature

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8. The British code recommended for long time deflection of cracked members is:

a) BS: 2150-1970

b) BS: 2150-1970

c) BS: 2150-1970

d) BS: 2150-1970

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9. The additional long term deflection resulting from creep and shrinkage of flexural members is determined by multiplying the deflection caused by:

a) Effective load

b) Compressive load

c) Tensile load

d) Sustained load

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10. The equation for long term deflection of cracked members is:

a) ξ/1+50ρ’

b) π/1+50ρ’

c) σ/1+50ρ’

d) e/1+50ρ’

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_{s}/bd) at midspan, A’

_{s}= area of compression reinforcement, b = width of the section, d = effective depth, ξ = time dependant factor.

## Prestressed Concrete Structures MCQ Set 4

1. Most compression members, such as long columns and piles are subjected to:

a) Bending moment and cracking forces

b) Bending moment and tension forces

c) Bending moment and axial forces

d) Bending moment and compression forces

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2. The load moment interaction diagrams are more or less similar to:

a) Prestressed columns

b) Reinforced concrete columns

c) Aluminium columns

d) Steel columns

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3. The compression failure mode develops under:

a) Static loading

b) Moment loading

c) Concentric loading

d) Tensile loading

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4. The balanced failure develops when there is simultaneous:

a) Tension yielding

b) Compression yielding

c) Flexure yielding

d) Prestress yielding

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_{b}. and this eccentricity factor is used for various failures considering top and bottom fibers.

5. The charts proposed by Bennett are useful in dimensioning columns of:

a) L section

b) I section

c) T section

d) Edge section

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6. The steps involved in design of biaxially loaded column are:

a) 15

b) 4

c) 8

d) 6

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7. The Prestressed concrete compression members should have a minimum average effective prestress of not less than:

a) 1.55n/mm^{2}

b) 1.0n/mm^{2}

c) 1.15n/mm^{2}

d) 1.25n/mm^{2}

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^{2}and the American code specifies the various effective prestress in prestressed concrete members considering all the factors and makes them economical.

8. The Spirals are particularly useful in increasing the:

a) Tensile strength

b) Ductility

c) Strain

d) Stress

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9. The pitch of spiral is computed as:

a) S = 4a_{s}(D_{c} – d_{s})/D_{c}^{2} ρ_{s}

b) S = 2a_{s}(D_{c} – d_{s})/D_{c}^{2} ρ_{s}

c) S = 6a_{s}(D_{c} – d_{s})/D_{c}^{2} ρ_{s}

d) S = 10a_{s}(D_{c} – d_{s})/D_{c}^{2} ρ_{s}

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_{s}(D

_{c}– d

_{s})/D

_{c}

^{2}ρ

_{s}, a

_{s}= cross sectional area of spiral, D

_{c}= core of the column measured to the outside diameter of the helix, d

_{s}= diameter of spiral wire, ρs = ratio of the volume of helical reinforcement.

10. The pitch of spirals is limited to a range of:

a) 40 to 45mm

b) 25 to75mm

c) 15 to 30mm

d) 10 to 30mm

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## Prestressed Concrete Structures MCQ Set 5

1. The design loads for various limit states are obtained as product of the:

a) Characteristic loads

b) Seismic loads

c) Ultimate loads

d) Wind loads

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_{d}= γ

_{f}F

_{k}, where F

_{d}= appropriate design load, γ

_{f}= partial safety factor for loads, F

_{k}= characteristic load.

2. The characteristic load is expressed as:

a) Mean load – K x standard deviation

b) Mean load + K x standard deviation

c) Load – standard deviation

d) Load + standard deviation

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_{k}which is independent of the limit state considered and is seldom exceeded in service is defined as: Characteristic load = Mean load + K x standard deviation, K is a factor so chosen as to ensure that the probability of the characteristic load being exceeded is small and a value of 1.64 for K ensures the probability that the characteristic load is exceeded by only 5 percent during the intended life of the structure.

3. The statistical data required to define the characteristic loads, need recording of data and:

a) Observations

b) Calculations

c) Loads

d) Stresses

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4. The characteristic values of the loads take account of expected variations but do not allow for:

a) Variations in stress

b) Variations in dimensional accuracy

c) Variation in strain

d) Variation in loads

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5. The values of partial safety factors are recommended for:

a) Loads

b) Designs

c) Spans

d) Beams

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6. The design strength of materials is expressed as:

a) F_{d} = F_{e} / γ_{k}

b) F_{d} = F_{c} / γ_{k}

c) F_{d} = F_{k} / γ_{m}

d) F_{d} = F_{d} / γ_{m}

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_{d}= F

_{k}/ γ

_{m}.

7. The term WL is termed as:

a) Wind load

b) Terrine

c) Live load

d) Wall load

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8. In characteristic strength of the material, the tensile strength of tendons below which the failure are not more than:

a) 6

b) 3

c) 5

d) 1

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_{k}is the characteristic strength of the material which corresponds to the 28 days cube strength compressive strength of concrete or the tensile strength of tendons below which the failures are not more than 5 percent.

9. The characteristic strengths of concrete and steel may be taken as the works cube strength and:

a) Yield strength

b) Strain

c) Stress

d) Principle strength

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10. The partial safety factor (γ_{m}) for materials has a value which depends upon the importance of the:

a) Principal sates

b) Limit states

c) Strain states

d) Stress states

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_{m}) for materials has a value depends upon the importance of limit states being considered, materials when tested and when incorporated in construction during service life of the structure.