250+ TOP MCQs on Advantages and Limitations and Answers

Prestressed Concrete Structures Multiple Choice Questions on “Advantages and Limitations”.

1. The structures of prestressed concrete are less liable to ___________
a) Bending
b) Loading
c) Placing
d) Cracks
Answer: d
Clarification: In case of fully prestressed members which are free from tensile stresses under working loads cross-section is more efficiently utilized when compared with a reinforced concrete section that is cracked under working loads.

2. Which of the following concrete offers pleasant appearance and durability?
a) Reinforced concrete
b) Prestressed concrete
c) Shrinkage concrete
d) Hardened concrete
Answer: b
Clarification: Prestressed concrete offers pleasant appearance and durability when compared to reinforced concrete and the two structural features of prestressed concrete, namely high strength concrete and freedom from cracks, contributes to the improved durability of structure under aggressive environmental conditions.

3. The prestressing members have better ability of absorbing energy when the structures are subjected to ___________
a) Tensile loads
b) Axial loads
c) Bending loads
d) Impact loads
Answer: d
Clarification: Prestressing of concrete improves the ability of the material for energy absorption under impact loads and working loads proved to be good in prestressing than in reinforcing and it is done in concrete members to reduce the compressive stresses developed in the members to the required extent.

4. The loads of same intensities when subjected to structures, it increases ___________
a) Life of material
b) Durability of material
c) Stiffness of material
d) Bending of material
Answer: a
Clarification: When loads of same intensities are subjected to structures, then the prestressing increases the mean stresses in steel and the effects caused due to fluctuations in stresses are minimized which increase the life of the material.

5. The prestressed concrete flexural member under working load conditions offers superior amount of ___________
a) Flexibility
b) Rigidity
c) Transfer
d) Stability
Answer: b
Clarification: A superior amount of rigidity is offered by the prestressed concrete flexural members under the working load conditions when compared with that offered by reinforced concrete members of equal dimensions.

6. The application of prestressed concrete is done for depth ratio’s having ___________
a) Small span
b) Larger span
c) Same span
d) Equal span
Answer: b
Clarification: Prestressed concrete is used for the construction of buildings and other structures which are having the value of span to depth ratio in large or for larger span members and other criteria such as equal, small, same span criteria are considered in various other structural members.

7. The prestressed concrete structures are considered as ___________
a) Economical structures
b) Uneconomical structures
c) Tensile structures
d) Loading structures
Answer: b
Clarification: Prestressed concrete structures are considered as uneconomical structures and it is well established fact that the basic economy of prestressed concrete lies in its high strength to weight and strength to cost ratios, its resistance to fire and cracking, and its versatility and adaptability.

8. The prestressed concrete involves problems like ___________
a) Architectural and construction
b) Financial and land
c) Placing of material
d) Tensioning devices
Answer: a
Clarification: The prestressed concrete involves many architectural or construction related problems formulated due to curved surfaces and involve sophisticated erection problems, a high quality control is required for production of materials and while placing the tendons and when the members are subjected to a system of loads then the existing problems due to long term creep moments are increased.

9. The utilization of concrete in tension zone of prestressed concrete member saves concrete ranging between ___________
a) 15 to 30 percent
b) 20 to 50 percent
c) 35 to 60 percent
d) 10 to 20 percent
Answer: a
Clarification: Due to the utilization of concrete in the tension zone, an extra saving of 15 to 30 percent in concrete is possible in comparison with reinforced concrete high tensile steels are used in prestressed members and its ultimate strength is equal to 2100n/mm2 and the saving in steel are even higher, 60 – 80 percent mainly due to high permissible stresses allowed in the high tension wires.

10. The overall economy in using prestressed concrete reduces?
a) Design loads and costs
b) Tendons
c) Anchorages
d) Bars
Answer: a
Clarification: An overall economy in using prestressed concrete decreases the dead weight due to which the design loads and cost of foundation reduces although there is considerable saving on the quantity of materials used in prestressed concrete members in compression with reinforced concrete members, it is not much significant due to additional costs incurred for high strength concrete, tensile steel, anchorages and other hard wires required for the production of prestressed member.