Prestressed Concrete Structures Multiple Choice Questions on “Historic Development”.
1. In 1886, Jackson of San Francisco applied for a patent in which prestress was introduced by ___________
a) Tensioning the reinforced rods in sleeves
b) Tensioning the reinforced rings in sleeves
c) Tensioning the reinforced steel in sleeves
d) Tensioning the reinforced bars in sleeves
Answer: a
Clarification: In present state of development in the field of prestressed concrete is due to continuous research done by engineers and scientists in this field during the last 90 years while Jackson of San Francisco applied for a patent “construction of artificial stone and concrete pavements”, in which prestress was introduced by tensioning the reinforced rods set in sleeves.
2. In 1888, manufacturing of slabs and small beams using embedded tensioned wires in concrete was introduced by ___________
a) Dohring
b) Karl marx
c) Emperger
d) Dischinger
Answer: a
Clarification: Dohring of Germany manufactured slabs and small beams in 1888, using embedded tensioned wires in concrete to avoid cracks, in 1923 Emperger of Vienna developed a method for making wire bound reinforced concrete pipes, the use of unbounded tendons was first demonstrated by Dischinger in 1928 and Karl marx was a German philosopher, economist, political theorist, sociologist, journalist.
3. An engineer mandl in 1896 put forward the idea to counteract the stresses acting due to ___________
a) Bending moment
b) Tension
c) Twisting moment
d) Loads
Answer: d
Clarification: The idea of prestressing to counteract the stresses due to loads was first put forward by the Austrian engineer Mandl in 1896 while bending moment, tension and twisting moment were considered as the basic concepts in strength of materials and this is an extension to structures subject with a new idea of prestressing making adverse advantages to the future structures.
4. In 1907, the losses of prestress due to elastic shortening of concrete was developed by ___________
a) Koenen
b) Steiner
c) Darcy
d) Hygen
Answer: a
Clarification: Koenon of Germany developed the subject by reporting in 1907, on the losses of prestress due to elastic shortening of concrete and Steiner recognized the losses due to shrinkage of concrete around 1908.
5. The importance of using high strength concrete and high tensile steel was introduced by ___________
a) Freyssinet
b) Hooke
c) Vienna
d) Newton
Answer: a
Clarification: Freyssinet in 1928-1933 has given the importance of using high strength concrete and steel in order to various losses of prestress due to creep and shrinkage and he also developed vibration technique to produce high strength concrete also manufactured double acting jack for stressing high tensile steel wires into the concrete structure.
6. The use of prestressed concrete in Europe and United states spread rapidly from?
a) 1945
b) 1935
c) 1933
d) 1944
Answer: b
Clarification: The use of prestressed concrete spread rapidly from 1935 onwards and many long span bridges, industrial shell roofs, marine structures, nuclear pressure vessels etc were constructed between 1945 and 1950 in Europe and United states.
7. In words of Guyon, more than a technique prestress is a ___________
a) Principle
b) Base
c) Strong material
d) Life for structures
Answer: a
Clarification: In the words of Guyon: “there is no structural problem to which prestress cannot provide a solution, and often a revolutionary one, Prestress is more than a technique; it is a general principle” is the description or explanation given by Guyon on prestressing.
8. Dischinger explained the use of unbounded tendons in the construction of ___________
a) Large bridges
b) Small bridges
c) Sleepers
d) Roofs
Answer: a
Clarification: Dischinger in 1928, has explained the use of unbounded tendons in the construction of large bridges of deep girder type by this method, the losses of prestress are neutralized by placing the prestressing wires inside the girder without any bond.
9. Vienna developed the method of wire bound reinforced concrete pipe by binding high tensile steel wires, the stresses in that were ranging in between ___________
a) 170 to 900
b) 100 to 800
c) 160 to 800
d) 140 to 200
Answer: c
Clarification: Vienna in 1923, has developed a wire bound reinforced concrete pipe by binding high tensile steel wires on pipe and In this method it was noticed that the stresses of concrete was ranging in between 160 to 800 n/mm2.
10. Prestressed concrete is widely used in construction by ___________
a) Houses
b) Bore wells
c) Roofs
d) Nuclear pressure vessels
Answer: d
Clarification: Prestressed concrete is used in construction of long span bridges, industrial roofs, marine structures, nuclear pressure vessels, water retaining structures, railway sleepers etc and it also has a higher modulus of elasticity and small creep strain, resulting in smaller loss of prestressing in the steel while prestressed concrete is one of the construction material in building and bridge products around the world.