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Objective type questions

1. In axially pre stressed members ,the concrete is under


• A)tension
• B)compression
• C)torsion
1. In pre stressed concrete members , the steel is under
• A)compression
• B)tension
• C)torsion
3.Prestressing is possible by using
• A)mild steel
• B)high-strength deformed bars
• C)high-tensile steel
5.Prestressing is economical for members of
• A)long span
• B)medium span
• C)short span
4.Prestressing steel has an ultimate tensile strength nearly
• A)twice that of HYSD bars
• B)thrice that of mild steel reinforcements
• C)four times that of HYSD bars
6.Linear prestressing is adopted in
• A)circular tanks
• B)pipes
• C)beams
7.Circular prestressing is advantageous in
• A)beams
• B)columns
• C)pipes and tanks
8.Prestressing wires in electric poles are
• A)concentric
• B)eccentric
• C)parabolic
ANSWERS
1. B
2. B
3. C
4. C
5. A
6. C
7. C
8. A
Objective type questions
1.The grade of concrete for prestressed members should be in the
range of
• A)M-20 to M-30
• B)M-80 to M-100
• C)M-30 to M-60
2.High-strength mixes should have a water/cement ratio of
• A)0.6 to 0.8
• B)0.3 to 0.4
• C)0.2 to 0.3
3.Creep of concrete in a structural member is due to
• A)elastic strain
• B)elastic-plastic strain
• C)inelastic strain
4.Shrinkage of concrete in a structural member is due to
• A)dead load on the member
• B)live load
• C)loss of moisture and drying of concrete
5.Modulus of elasticity of concrete is generally expressed in terms of
• A)shear strength
• B)compressive strength
• C)tensile strength
6.Target mean strength of concrete depends upon
• A)water/cement ratio
• B)type of aggregate
• C)characteristic strength of concrete
7.Workability of concrete is influenced significantly by
• A)target mean strength
• B)water/cement ratio
• C)type of cement
8.High-tensile steel is basically
• A)low carbon steel
• B)high manganese steel
• C)high carbon steel
ANSWERS
1. C
2. B
3. C
4. C
5. B
6. C
7. B
8. C
Objective type questions
1.In prestressing system
• A) the member is cast first followed by tensioning of high-tensile
wires
• B) the member is prestressed by external anchors
• C) the high-tensile wires are tensioned before placing concrete in
forms
2.Curved cables can be used in
• A)pretensioned members
• B)externally prestressed members
• C)post-tensioned members
3.In long line method or pretensioning.
• A) only one method can be cast
• B) two members can be cast
• C)Several members can be cast
4.In post-tensioning system
• A)wires are first tensioned followed by concreting
• B)tensioning of wires and concreting is simultaneously done
• C)the wires are tensioned against hardened concrete
5.Freyssinet system is based on the principle of
• A)direct bearing on concrete from bolt heads at the end of wires
• B)looping of the wires around concrete
• C)wedge action producing frictional grip between steel & concrete
6.High-tensile bars threaded at ends are used in
• A)Freyssinet
• B)Giffords-Udall system
• C)Lee-McCall system
7.Looping of high-tensile tendons around the concrete is used in
• A)BBRV system
• B)Magnel-Blaton system
• C)Baur-Leonhardt system
8.Tendon splices are required im
• A)Hoyer’s long line method of pretensioning
• B)Short span prestressed members
• C) Long span continuous members
ANSWERS
1. C
2. C
3. C
4. C
5. C
6. C
7. C
8. C
Objective type questions
1.High strength concrete is used for pre-stressed concrete because of
• A)lesser prestress loss
• B)high tensile strength
• C)low creep
• D)low brittleness
2.In limit-state of design of prestressed concrete, which of the
following strain distribution is assumed?
• A)linear B)bilinear curve
• C)parabolic c)none of the above
3.To manufacture concrete sleepers, which of the following method is
used?
• A) Post-tensioning B) Pre-tensioning
• C) Partial pre-stressing D) None of the above
4.Which of the following system are used as anchorage for post-
tensioning?
A) Fressinet system B) Magnel Balton system
C) Gifford-Udall system D) Lee-McCall system
E) All of the above
5.Ultimate moment capacity of pre-stressed concrete beam depends
on
• A)Amount of tensioning B)Losses in prestressing
• C)Eccentricity of cable D)All of the above
6.Loss of prestress in concrete due to shrinkage does not depend on
• A)Modulus of elasticity of concrete
• B)Modulus of elasticity of steel
• C)Shrinkage in concrete
• D)None of above
7.Under self-weight, a balanced prestressed cross section is subjected
to
• A)axial stress B)bending stress
• C)axial & shear stress D)shear stress
8.Stress at the bottom edge of a simply supported beam corresponding
to the cracking moment is called
• A)modulus of rupture
• B)modulus of elasticity
• C)characteristic compressive strength
• D)ultimate tensile strength
ANSWERS
1. C
2. A
3. B
4. E
5. D
6. A
7. C
8. A
1. The prestressed concrete poles are currently used in:
a) Mass
b) Heat
c) Current
d) Wave

2. The appearance of prestressed concrete poles is:


a) Rusty
b) Greesy
c) Clean
d) Black

3. The maximum moment of resistance in a pole is generally required at:


a) Base
b) Corner
c) Edge
d) Middle

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