Concrete Technology And Design Set 5 MCQs

Q1 | The maximum amount of dust which may be permitted in aggregates is

5% of the total aggregates for low workability with a coarse grading

10% of the total aggregates for low workability with a fine grading

20% of the total aggregates for a mix having high workability with fine grading

all the above

Q2 | Bulking of sand is

mixing of different sizes of sand particles

mixing of lime with sand

maximum water with sand

swelling of sand when wetted

Q3 | For a longitudinal reinforcing bar in a column, the minimum cover shall neither be less than thediameter of bar nor less than

15 mm

25 mm

30 mm

40 mm

Q4 | Workability of concrete is measured by

vicat apparatus test

slump test

minimum void method

talbot richard test

Q5 | The size of fine aggregates does not exceed

2.75 mm

3.00 mm

3.75 mm

4.75 mm

Q6 | The main reason for providing number of reinforcing bars at a support in a simply supported beamis to resist in that zone

compressive stress

shear stress

bond stress

tensile stress

Q7 | The entrained air in concrete

increases workability

decreases workability

decreases resistance to weathering

increases strength

Q8 | According to IS: 4561978, the flexural strength of concrete is

directly proportional to compressive strength

inversely proportional to compressive strength

directly proportional to square root of compressive strength

inversely proportional to square root of compressive strength

Q9 | Slump test is done for

clay

sand

lime

concrete

Q10 | Di-calcium silicate (C2S)

hydrates rapidly

generates less heat of hydration

hardens rapidly

provides less ultimate strength to cement

Q11 | The limits of percentage p of the longitudinal reinforcement in a column is given by

0.15% to 2%

0.8% to 4%

0.8% to 6%

0.8% to 8%

Q12 | The risk of segregation is more for

wetter mix

larger proportion of maximum size aggregate

coarser grading

all the above

Q13 | Le-Chatelier's apparatus is used for testing

soundness of cement

hardness of cement

strength of cement

durability of cement

Q14 | Construction joints are generally provided in concrete

roads

retaining walls

lining of canals

all the above

Q15 | If a grading curve is horizontal between the portions of 20 mm I.S. Sieve and 4.75 mm I.S. Sieve,the graded aggregates do not contain

20 mm particles

10 mm particles

4.75 mm particles

all the above

Q16 | Most common method of pre-stressing used for factory production is

long line method

freyssinet system

magnel-blaton system

lee-macall system

Q17 | C.R.R.I. charts are used to obtain a relationship between strength of concrete and

water cement ratio

workability

grading of aggregate

fineness modulus

Q18 | For the design of retaining walls, the minimum factor of safety against overturning is taken as

1.5

2.0

2.5

3.0

Q19 | If the depth of moist sand in a cylinder is 15 cm and the depth of the sand when fully inundatedwith water is 12 cm, the bulking of the moist sand, is

10 %

12 %

15 %

25 %

Q20 | If aggregates completely pass through a sieve of size 75 mm and are retained on a sieve of size 60mm, the particular aggregate will be flaky if its minimum dimension is less than

20.5 mm

30.5 mm

40.5 mm

50.5 mm

Q21 | If the foundations of all the columns of a structure are designed on the total live and dead loadbasis, then

there will be no settlement of columns

there will be no differential settlement

the settlement of exterior columns will be more than interior columns

the settlement of interior columns will be more than exterior columns

Q22 | Saw dust can be rendered chemically inert by boiling it in water containing

ferrous sulphate

potassium chloride

ammonia

nitric acid

Q23 | A concrete having a slump of 6.5 cm, is said to be

dry

earth moist

semi-plastic

plastic

Q24 | To obtain a very high strength concrete, use very fine grained

granite

magnetite

barite

volcanic scoria

Q25 | Vicat apparatus is used for

fineness test

consistency test

test for setting time

test for tensile strength