Civil engineer objective questions – Concrete Technology (Section-13)

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