301. Higher workability of concrete is required if the structure is
a ) made with cement concrete
b ) thick and reinforced
c ) thin and heavily reinforced
d ) thick and heavily reinforced
302. Pick up the correct statement form the following :
a ) higher workability indicates unexpected increase in the moisture content
b ) higher workability indicates deficiency of sand
c ) if the concrete mix is dry , the slump is zero
d ) concrete mix having zero slump , is unsuitable for high strength
e ) all of the above
303. The maximum thickness of concrete floor of a cement warehouse , is
a ) 10 cm
b ) 15 cm
c ) 20 cm
d ) 25 cm
304. The shuttering of a hall measuring 4 mx 5m , can be removed after
a ) 5 days
b ) 7 days
c ) 10 days
d ) 14 days
305. Pick up the correct statement from the following
a ) there should not be any loss of cement from the charged drum of the mixer
b ) cement should be mixed for at least one minute
c ) 10 % of water is placed in the rotating drum before adding dry materia l
d ) 10 % of water is added after placing the other ingredients in the drum
e ) all of the above
306. If the effective working time is 7 hours and per batch time of concrete mixer of 150 litre capacity , is
a ) 15,900 litres
b ) 16,900 litres
c ) 17,900 litres
d ) 18,900 litres
307. The main object of compaction of concrete is
a ) to eliminate air holes
b ) to achieve maximum density
c ) to provide intimate contact between the concrete and embedded materials
d ) all of the above
308. Non – uniform compaction may cause the concrete
a ) porous
b ) non – homogeneous
c ) reduced strength
d ) all of the above
309. The compaction of concrete , improves
a) density
b ) strength
c) durability
d ) all of the above
310. The final operation of finishing floors , is known
a ) screening
b ) floating
c ) trowelling
d ) finishing
311. The operation of removing humps and hollows of uniform concrete surface , is known as
a ) floating
b ) screeding
c ) trowelling
d ) finishing
312. The ratio of the length and breadth of wooden float , is
a ) 4.5
b ) 5.5
c ) 6.5
d ) 7.5
313. Construction joints are provided
a ) where BM and SF are small
b ) where it is supported by another member
c ) at 18 m apart in huge structures
d ) in concrete wall at sill level of windows
e ) all of the above
314 . The surface where two successive placements of concrete meet , is known as provided at
a ) contraction joint
b) expansion joint
c ) construction joint
d) both (a) an (b) of above
315. A construction joint is provided where
a ) bending moment is small
b ) shear force is small
c ) it is supported by other member
d ) all of the above
316. Horizontal construction joins in concrete walls are generally provided at
a ) soffit level
b ) window sill level
c ) floor level
d ) all of the above
317. Pick up the correct statement from the following :
a ) construction joints in columns are provided a few cm below the junction of beam
b ) construction joints in columns are provided at the bottom haunching
c ) construction joints in beam and slabs are provided within middle third
d ) construction joints are generally provided in positions subjected to least shear force
e ) all of the above
318. Joints in concrete structures , are provided
a ) to reduce the tensile stresses likely to be developed due to evaporation of water
b ) to minimize the change in the dimensions of the slab
c ) to minimize the necessary cracking
d ) all of the above
319. Expansion joints are provided if the length of concrete structures exceeds
a ) 10 m
b ) 15 m
c ) 20 m joints
d ) 40 m
320. According to the recommendations of IS : 456-2000 , expansion
a ) are provided where plane changes abruptly
b ) are provided to ensure minimum resistance
c ) are supported on separate columns
d ) do not carry reinforcement across them
e ) all of the above
321. Construction joints are generally provided in concrete
a ) roads
b) retaining walls
c ) lining of channel
d) lining of tunnels
e ) all of the above
322. Pick up the correct statement from the following :
a ) construction joins are necessarily planned for their locations
b ) expansion joints are provided to accommodate thermal expansion
c ) construction joints are provided to control shri nkage cracks
d ) expansion joints need not be provided in foundation concrete
e ) all of the above
323. The main purpose of concrete design mix is
a ) economise the cost of concrete
b ) mixing the concrete in better way
c ) selection of ingredients of concrete
d ) none of the above
324. Generally nominal mix is done by
a ) volume
b) weight
c ) both ( a ) and ( b ) of above
d ) consolidation
325. Choose the correct statement from the following :
a ) the free water is the amount of water added while mixing and the amount of water held on the surface of the aggregates prior to mixing
b ) the total water is the free water and the amount actually absorbed by the aggregates
c ) both ( a ) and ( b ) of above
d ) none of the above