Category: Prestressed Concrete Structures Objective Questions

250+ TOP MCQs on Cracking Moments and Answers

Prestressed Concrete Structures Multiple Choice Questions on “Cracking Moments”.

1. The soffit of the beam after the transfer of prestress to concrete will be under ____________
a) Tension
b) Compression
c) Breakage
d) Bondage
Answer: b
Clarification: The bending moment at which visible cracks developed in prestressed concrete members is generally referred to as the cracking moment after the transfer of prestress to concrete, the soffit of the beam will be under compression.

2. The compressive and tensile stresses developed in cracking moments are due to ____________
a) Bending loads
b) Transverse loads
c) Tensile loads
d) Compressive loads
Answer: b
Clarification: These compressive stresses are balanced by the tensile stresses developed due to the transverse loads on the beam, so that the resultant stress at the bottom fiber is zero, a further increase in loading results in the development of tensile stresses at the soffit of beam.

3. The micro cracks develop as soon as the tensile strain in concrete exceeds about ____________
a) 80-100×10-6 units
b) 100-150×10-6 units
c) 150-300×10-6 units
d) 300-500×10-6 units
Answer: a
Clarification: As concrete is weak in tension, micro cracks develop as soon as the tensile strain in concrete exceeds about 80-100×10-6 units and the parameters in concrete are influenced by various materials and their permissible values according to Indian standard codes.

4. When the loads in a concrete member are further increased than permitted, the crack widths are of an order of limit?
a) 0.01-0.02mm5
b) 0.05-0.10mm5
c) 0.03-0.05mm5
d) 0.07-0.08mm5
Answer: a
Clarification: If the loads are further increased, than 80-100×10-6 units visible cracks appear in the tension zone and at this stage, it is estimated that the crack widths are of an order of 0.01-0.02mm5 and these width of cracks are considered from a value of minimum to maximum not excess till permitted.

5. A rectangular concrete beam of cross section 120mm wide and 300mm deep is prestressed by a straight cable, effective force of 180kn at an eccentricity 50, area of 36×103mm2(z=18×105mm3). Find the total stress due to prestress?
a) 10
b) 25
c) 35
d) 45
Answer: a
Clarification: P = 180kn, A = 36×103mm2, e = 50mm, b = 120mm, d = 300mm, z = 18×105mm3
Stresses due to prestress = (p/a) = (180×103/36×103) = 5n/mm2, (pe/z) = (180×103×50/18×105) = 5n/mm2

Total stress = ((p/a)+(pe/z))=(5+5) = 10n/mm2.

6. A rectangular concrete beam of cross section 100mm wide and 400mm deep is prestressed by a straight cable of span 6m, imposed load is 3.14kn/m, area is 36×103mm2(Z=18×105mm3). Calculate working moment assuming the self weight of concrete as 24kn/m3?
a) 10.25
b) 2.25
c) 3.25
d) 4.25
Answer: a
Clarification: Z = 18×105mm3, A = 36×103mm2, G = (0.1×0.4×24) = 0.96kn/m
Total load W = (g+q) = (0.96+3.14) = 4.1kn/m, Maximum working moment = (0.125×4×62) = 18.45knm
(M/Z) = (18.45×106/18×105) = 10.25n/mm2.

7. When the tensile stresses are developed in the cracks, they are visible at ____________
a) Hoop stress of beams
b) Soffit of beams
c) Sagging of beams
d) Hogging of beams
Answer: b
Clarification: The tensile stresses are developed when cracks become visible at the soffit of beams depend upon the type and distribution of steel reinforcement and the quality of concrete in beam, at the soffit of the beam concrete behaves according to influencing parameters of steel reinforcement.

8. The cracks appear when the tensile stresses at the soffit are equal to ____________
a) Modulus of elasticity
b) Modulus of rupture
c) Tension modulus
d) Reinforcement modulus
Answer: b
Clarification: It is generally considered that visible cracks appear when the tensile stresses at the soffit are approximately equal to modulus of rupture of the material, it is an ultimate strength pertaining to failure of beams by flexure equal to the bending moment at rupture divided by the section modulus of beams.

9. The widths of the cracks are influenced by ____________
a) Degree of bond
b) Stress
c) Strain
d) Tension
Answer: a
Clarification: The widths of the cracks are highly influenced by the degree of bond developed between concrete and steel and stress corrosion cracking results from the combined action of corrosion and static tensile stress which may be either residual or externally applied.

10. The formulae for load factor against cracking is ____________
a) Cracking moment/Working moment
b) Cracking moment/Bending moment
c) Cracking moment/Tensile moment
d) Cracking moment/Aerial moment
Answer: a
Clarification: The beam at which visible cracks developed in prestressed concrete members is generally referred to as the “cracking moment” and their formula for load factor against cracking is cracking moment/working moment.

250+ TOP MCQs on Cable Profile and Cable Layout and Answers

Prestressed Concrete Structures Multiple Choice Questions on “Cable Profile and Cable Layout”.

1. The concept of load balancing is useful in selecting?
a) Anchorage profile
b) Shaft profile
c) Tendon profile
d) Span profile
Answer: c
Clarification: The concept of load balancing is useful in selecting a tendon profile and they provide suitable force system in concrete member, consider a prestressed concrete beam which is provided with a tendon at an eccentricity and is subjected to a hogging moment such that the beam deflects, the slope gets modified as the beam is subjected to a downward external load, if the beam is subjected to a UDL of W per unit run for the complete span, then the net slope at each end can be calculated as:
Δ = Wl3/24EcI – Pel/2EcI.

2. In a prestressed concrete member, cable profile is suitable for balancing loads of __________
a) External type
b) Internal type
c) Bent type
d) Curved type
Answer: a
Clarification: In a prestressed concrete member, external type of loads is balanced by transverse component of suitable cable profile, on effect of loading the net deformation increases the stress, strain and length of the tendon, extension of tendon = 2eδ, increase in strain 2eδ/l, increase in stress = 2eδ/l Ec.

3. The reactions of cable are obtained by replacing the forces acting on __________
a) Reinforcement
b) Concrete
c) Edges
d) Steel
Answer: b
Clarification: The shape of profile depends on the reaction of cable and these are obtained by replacing the forces acting on concrete with tendons, a prestressed concrete beam with bent tendons has extreme fiber stress, f = P/A+M/z and P/A-M/Z, prestressed concrete beam with parabolic tendon has a net downward force acting on the beam as F = W-We.

4. In a concrete member, trapezoidal cable profile is adopted when the beam is subjected to __________
a) UDL
b) SSB
c) Point loads
d) Concentrated loads
Answer: d
Clarification: In a concrete member, trapezoidal profile is adopted when the beam is subjected to two concentrated loads and parabolic profile is used when it is subjected to UDL, the curve and sharp angles of cable develop uniformly distributed and concentrated loads respectively and the straight portion of cable does not produce any reactions at the end.

5. The net downward force of prestressed concrete beam with bent tendon is given as __________
a) W-2psinθ
b) W+2psinθ
c) Zero
d) 2
Answer: a
Clarification: Bent tendons are used in prestressed concrete beams as they tends to provide an upward pressure in the beam and hence reduces the effect of external loading to a great extent, consider a prestressed concrete beam AB of length l it is subjected to a point load W at centre and a prestressing force of P at the ends, the tendon is bent at an angle of θ at the ends, neglecting the frictional losses, the tendon will develop an upward force of magnitude 2Psinθ at the bent at the centre of span, the upward force reduces the effect of the externally applied force in the beam considering equilibrium in vertical direction, the net downward force F = W-2psinθ.

6. The pressure line is also known as __________
a) C line
b) E line
c) G line
d) I line
Answer: a
Clarification: Consider a beam which is lying over the ground provided with a tendon and is free from all external loads such that the beam remains unaffected by any external bending moments, the tension force and compression force act at the same level when no external bending moments are acting over the beam and the tendon line (p line) or the line in which compressive force is acting is known as pressure line and it is also known as P line or C line.

7. In the concept of pressure line the C line moves over a P line due to the effect of __________
a) Stress
b) Strain
c) Moment
d) Prestress
Answer: c
Clarification: If the beam is effected by a moment M, in pressure line then the C line moves over the P line at a distance x and the distance is known as lever arm,
x = M/P = external moment/p, x = shift of C line from P line.

8. If the section of a rectangular beam is subjected to the prestressing force and dead load then the stress distribution is given by __________
a) Pressure line
b) Kern distance
c) Permissible pressure
d) Fracture of steel
Answer: b
Clarification: Consider a rectangular beam section subjected to a prestressing force of magnitude p and if the section is subjected to the prestressing force and live and dead load only then the stress distribution across the section is given by kern distance in the form of upper and lower kern distance.

9. If the force acts at the lower kern point then the bottom fibers of the beam are subjected to __________
a) Maximum permissible stress
b) Minimum permissible stress
c) Tensile stress
d) Principle stress
Answer: a
Clarification: The points a, b, represents the points of application of forces P and C respectively, now if the beam is subjected to live load in addition to dead load and prestress then the point of application of force c reach point a from point a the point of application of force p and the magnitude of force C remain unchanged, if 0 represents the centroid of the beam section, then the distance ob is kb and oa’ is kt, if the force C acts at the lower kern point the bottom fibers of the beam are subjected to maximum permissible stresses and the top fibers are subjected to minimum permissible stress.

10. The strength concept can also be used to determine the position of __________
a) Kern line
b) C line
c) S line
d) E line
Answer: b
Clarification: The strength concept can also be used to determine the position of c line, eccentricity and distribution of stress in concrete and it is expressed as:
Extreme stress in concrete = C/A+ or – Eccentricity of c/Z.

250+ TOP MCQs on Design Loads and Strengths and Answers

Prestressed Concrete Structures Multiple Choice Questions on “Design Loads and Strengths”.

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
Answer: a
Clarification: The design loads for various limit states are obtained as products of the characteristic loads and partial safety factor and are expressed as:
Fd = γf Fk, where Fd = appropriate design load, γf = partial safety factor for loads, Fk = 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
Answer: b
Clarification: The characteristic load Fk 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
Answer: a
Clarification: The statistical data required to define the characteristic loads for different types of occupancy is not readily available, since loading statistics are invariably difficult to compile as they need a systematic observations and recording of data on loading and the nominal imposed loads provided in various national codes, such as IS: 875-1987, BS: 6399 may be treated as characteristic loads.

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
Answer: b
Clarification: The characteristic values of the loads take account of expected variations but do not allow possible unusual increases in load beyond those considered in deriving the characteristic load, in accurate assessment of effects of loading and unforeseen stress distribution within the structure and variations in dimensional accuracy achieved in construction.

5. The values of partial safety factors are recommended for ____________
a) Loads
b) Designs
c) Spans
d) Beams
Answer: a
Clarification: Partial safety factor γf are therefore used for each limit state being reached and the values of partial safety factors for loads recommended in the British, Indian and American codes and FIP recommendations.

6. The design strength of materials is expressed as ____________
a) Fd = Fe / γk
b) Fd = Fc / γk
c) Fd = Fk / γm
d) Fd = Fd / γm
Answer: c
Clarification: FIP recommendations regarding partial safety factors are comprehensive, as they provide for a combination coefficients for basic variable actions as well as for other variable factors depending upon different types of structures, such as dwellings, offices, parking area and highway bridges and the design strength of materials are expressed as: Fd = Fk / γm.

7. The term WL is termed as ____________
a) Wind load
b) Terrine
c) Live load
d) Wall load
Answer: a
Clarification: DL is the dead load, LL is the live load and WL is the wind load while considering earthquake effects substitute EL for WL and these loads are considered while calculation of loads and deflections of the beam.

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
Answer: c
Clarification: Fk 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
Answer: a
Clarification: In the absence of statistical data, the characteristic strengths of concrete and steel may be taken as the works cube strength and the specified proof or yield strength respectively as provided for in the codes.

10. The partial safety factor (γm) for materials has a value that depends upon the importance?
a) Principal sates
b) Limit states
c) Strain states
d) Stress states
Answer: b
Clarification: The partial safety factor (γm) 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.

250+ TOP MCQs on Flexural and Shear Strength and Answers

Prestressed Concrete Structures Multiple Choice Questions on “Flexural and Shear Strength”.

1. In the case of composite sections, the percentage of tensioned reinforcement is less than?
a) Simple beams
b) Complex beams
c) Tee beams
d) Edge beams
Answer: a
Clarification: In case of composite sections the percentage of tensioned reinforcement is less than that in most simple beams so that the section is invariably under reinforced and the compression zone generally consists entirely of insitu concrete of lower compressive strength, and the value of the cube strength of concrete to be used in flexural strength equations will obviously be that of insitu cast concrete.

2. If the compression zone contains part of precast element, the computation is done by considering?
a) Grades of concrete
b) Cross section
c) Durability
d) Strength characteristics
Answer: b
Clarification: If the compression zone contains a part of precast element, the average compressive strength computed by considering the cross sectional area of insitu and precast concrete is used in the computation of compressive force.

3. The effective bonding between the two parts of composite beams is developed by _______________
a) Smoothing
b) Roughening
c) Painting
d) Detacahing
Answer: b
Clarification: Effective bending between the two parts of a composite beam may be developed by providing castellation in the precast unit or by roughening the contact surface of the precast unit before placing the insitu concrete or by projecting reinforcements from the precast unit which serve as ahead connectors.

4. The design of shear connections depends upon the strength of ____________
a) Ex situ cast concrete
b) In situ cast concrete
c) Tampered concrete
d) Prestressed concrete
Answer: b
Clarification: In the design of shear connection it is generally assumed that the natural bond at the interface contributes a part of the required shear resistance depending upon the strength of the insitu cast concrete and the roughness of the precast element and any extra shear resistance over and above this should be provided by shear connectors.

5. When ties are not provided the permissible values of the horizontal shear stress is?
a) 0.6n/mm2
b) 4.6n/mm2
c) 1.6n/mm2
d) 8.6n/mm2
Answer: a
Clarification: The permissible values of the horizontal shear stress for different types of contact surfaces is specified as: 0.6n/mm2 when ties are not provided and the contact surface of the precast element is free of laitance and intentionally roughened to an amplitude of 5mm and 25n/mm2 when minimum vertical ties are provided and the contact surface is roughened to an amplitude of 5mm.

6. The ties consisting of single bars and multiple leg stirrups should have a spacing not exceeding ____________
a) 600mm
b) 400mm
c) 1100mm
d) 900mm
Answer: a
Clarification: The ties consisting single bars, multiple leg stirrups or vertical legs of welded face fabric should not have a spacing not exceeding four times the least dimension of the supported element nor 600mm whichever is less the Indian standard code IS: 1343 does not make any specific recommendations regarding the shear stresses in composite sections.

7. If the surface is rough tamped and without links to withstand a horizontal shear stress of 0.6n/mm2 and assuming the moduli of elasticity of precast and insitu cast concrete to be equal the centroid of the composite section is located 110mm from the top of the slab, second moment area of composite section is 2487×105mm4, calculate ultimate shearing resistance?
a) 14
b) 12
c) 18
d) 21
Answer: b
Clarification: vu = ultimate shearing force, τ = vus/ln, s= (350x30x95)mm3, b = 80mm, τ = 0.6n/mm2, vu = (0.6x2487x105x80/350x30x95) = 12000n = 12kn.

8. Design ultimate horizontal shear stress with nominal links and the contact surface are as cast (assume τ = 1.2n/mm2)?
a) 15kn
b) 23kn
c) 12kn
d) 24kn
Answer: d
Clarification: The ultimate shear resistance is expressed as vu = (τlb/s) = (1.2x2487x105x80/350x30x95) = 24000n = 24kn, τ = 1.2n/mm2.

250+ TOP MCQs on Dimension of Stresses and Answers

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.

250+ TOP MCQs on Historic Development and Answers

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.