Prestressed Concrete Structures Multiple Choice Questions on “Dimension of Stresses”.
1. The span of trusses generally lies in the range of __________
a) 18-30m
b) 20-30m
c) 40-50m
d) 12-18m
Answer: a
Clarification: The height of reinforced concrete truss at midspan is in the range of 1/7 to 1/9 of its span length and the span of the trusses generally lies of the range of 18-30m and these spans are commonly used for bridge decks.
2. The width of various components is kept constant at __________
a) 100-200mm
b) 200-350mm
c) 150-300mm
d) 1200-1400mm
Answer: b
Clarification: The width of the various compression and tension members is kept constant at 200-350mm depending upon the span of the truss and the depth of top bottom members which are in compression generally is the range of 200-300mm.
3. The bottom tie member should be sufficient size to __________
a) Tension
b) Stress
c) House
d) Strain
Answer: c
Clarification: The bottom tie members should be of sufficient size to house the pretensioned wires or post tensioned cables and the depth is around 200mm for spans of 15m and increasing to 300mm for spans of 30m.
4. The depth of diagonal web members is at a range of __________
a) 100-150
b) 200-250
c) 110-210
d) 114-115
Answer: a
Clarification: The depths of diagonal web members which are in comparison and tension generally vary in the narrow range of 100-150mm but they are not limited and they change the values from one to another diagonal web members.
5. The use of concrete trusses with modular coordination for spans of 6and 9 are common for countries like?
a) America
b) Poland
c) India
d) Nueziland
Answer: b
Clarification: The use of concrete trusses with modular coordinates for spans of 6,9,12,15,18,24,30 and 36m with a base module of 30m is most common for industrial buildings of east European countries such as Russia, Poland, Slovakia, Germany, Branko zezelji has reported the construction of reinforced concrete wit prestressed tie members for spans up to 60m in erstwhile Yugoslavia.
6. The precast pretensioned cored slabs having circular or elliptical cavities have been used in __________
a) France
b) Russia
c) Phillipines
d) Losangles
Answer: b
Clarification: Prestressed concrete is ideally suited for office, industrial and commercial buildings when large column free open spaces are required and precast pretensioned cored slabs having circular or elliptical cavities have been widely used in Russia for floor panels of multistory buildings.
7. The prestressed concrete folded plate units are also widely used to cover roofs of __________
a) Industrial buildings
b) Commercial buildings
c) Structural buildings
d) Regional buildings
Answer: a
Clarification: Folded plates prestressed with curved cables to cover the 60m span roof of a town hall in west phalia, germany and in comparison with types of roofs, folded plate roof provides the most economical solution with minimum maintenance costs.
8. Prestressed hollow inverted pyramids have been used as a transfer in?
a) Girder system
b) Flange system
c) Block system
d) Chain system
Answer: a
Clarification: Prestressed hollow inverted pyramids have been used as a transfer: Girder system to support the four storey complex housing the administration building for engineering construction corporation limited at manapakkam in madras and the upper four storeys housing the administrative complex rest on four hollow prestressed pyramids which in turn are supported on hollow core walls.
9. Another example of application of prestressed concrete in buildings can be seen in construction of __________
a) 11 – storied structure
b) 13 – storied structure
c) 10 – storied structure
d) 15 – storied structure
Answer: a
Clarification: 11 storied cast in situ reinforced concrete structure which has the upper 8 stores resting on reinforced concrete arched girders with prestressed concrete ties spanning nearly 18m this is suited for large columns free space for conference halls, auditoriums, sports stadiums, industrial structures and in such cases prestressed concrete is invariably selected due to its inherent high strength durability and economy.
10. The design of joint should allow __________
a) Retardation
b) Translation
c) Sublimination
d) Axial
Answer: b
Clarification: The design of the joint should allow free translation, deflection and rotation of the structure at the edges without damage or in convenience to the traffic and the expansion joint should be strong enough to withstand the knocking of wheels of vehicles passing over the bridge deck.