351. The minimum clear horizontal spacing between groups of cables or ducts of grouped cables shall be greater of
a ) 30 mm or 5 mm more than maximum size of aggregate
b ) 40 mm or 5 mm more than maximum size of aggregate
c ) 30 mm or maximum size of aggregate
d ) 40 mm or maximum size of aggregate
352. The minimum clear vertical spacing between groups of cables or ducts of grouped cables shall be
a ) 30 mm
b ) 40 mm
c ) 50 mm
d ) none of the above
353. The grouting of ducts in post – tensioned prestressed concrete causes
a ) reduction in deflections
b ) reduction in crack width
c ) reduction in corrosion
d ) all of the above
354. A parabolic tendon in prestressed beam causes an equivalent balancing
a ) concentrated shear force
b ) constant moment
c ) distributed force
d ) uniformly distributed force
355. An increase in strain in a concrete member at constant stress is called
a ) creep loss
b ) relaxation
c ) shrinkage
d ) transfer stress
356. Strain in concrete at zero stress is called
a ) creep loss
b ) relaxation
c ) shrinkage
d ) transfer stress
357. In case of prestressed concrete , prestressing force is
a ) tensile force
b ) compressive force
c ) shear force
d ) momentum force
358. In case of prestressed concrete
a ) load carrying capacity of member increases
b ) quantity of concrete is saved for same grade
c ) quantity of steel is saved for same grade
d ) all of the above
359. Light weight concrete is prepared by
a ) using light aggregate
b ) formation of air void in concrete by omitting sand
c ) formation of air voids in cement paste by the substances causing foam
d ) all of the above
360. Light weight concrete is used in
a ) heat resistance
b ) air conditioning of buildings
c ) non load bearing wall
d ) reducing thickness
361. To obtain a light weight concrete the types of aggregate used is
a ) granite
b ) magnetite
c ) barite
d ) pumice
362. A concrete in which dry coarse aggregate are first packed to have the least voids and then the cement sand mortar is injected under pressure to fill all the voids , resulting in a very dense concrete , is known as
a ) pre – packed concrete
b ) vacuum concrete
c ) no fines concrete
d ) aerated concrete
363. The ferrocement is a composite material obtained by
a ) random disposal of short , discontinuous fibres in the conventional concrete
b ) reinforcing the cement mortar with steel fibres in the form of wire mesh
c ) blending ferrous compounds in the ordinary Portland cement
d ) all of the above
364. The cement sand ratio in the ferrocement matrix should not be leaner than
a ) 1 : 1.5
b ) 1 : 2
c ) 1 : 2.5
d ) 1 : 3
365. The volume of reinforcement in ferrocement ( percent ) normally varies between
a ) 1-2
b) 2-5
c ) 5-8
d) 8-10
366. The water cement ratio for ferrocement mix should be
a ) less than 0.35
b ) between 0.35 to 0.40
c ) between 0.40 to 0.45
d ) between 0.45 to 0.60
367. What is the process of smoothening the surface of newly placed concrete with a trowel called ?
a ) hardening
b ) knocking up
c ) flashing
d ) floating
368. If water cement ratio is more ,
a ) the durability of the concrete will be more
b ) the durability of the concrete will be less
c ) the durability of the concrete will not be affected
d ) none of the above
369. Low water – cement ratio in concrete :
a ) reduces the permeability of concrete
b ) increases the compressive strength
c ) improves the frost resistance of concrete
d ) all of the above
370. To get ultra high strength concrete ,
a ) compaction by pressure and helical binding
b ) polymerization in concrete
c ) reactive powder concrete
d ) all of the above
371. As compared to Ordinary Portland Cement , use of pozzolanic
a ) reduces workability
b ) increases bleeding
c ) frustum of a cone cement :
c ) increases shrinkage
d ) increases strength
372 , Steel mould used for slump test is in the form of :
a ) cube
b ) cylinder
c) frustum of a cone
d ) triangular
373. The interval for which the cement products remain in plastic condition is known as ::
a ) reaction time
b ) hardening time
c ) curing time
d ) setting time
374. The compressive strength of an ordinary Portland cement ( 1 : 3 :: Cement : sand ) after seven days test should not be less than :
a ) 115 kg / cm2
b ) 175 kg / cm²
c ) 220 kg / cm²
d ) 275 kg / cm²
375. The concrete in which preliminary tests are preformed for designing the mix is called :
a ) ordinary concrete
b ) rich concrete
c ) controlled concrete
d ) lean concrete
