Concrete Technology MCQs

Question 1

The bulk density of aggregates, is generally expressed as

Accepted Answer

kg/litre

Answer

tonnes/cubic metre

Answer

kg/cubic metre

Answer

g/cm3

Question 2

The risk of segregation is more for

Accepted Answer

all the above

Answer

wetter mix

Answer

larger proportion of maximum size aggregate

Answer

coarser grading

Question 3

Pick up the correct statement from the following :

Accepted Answer

All the above

Answer

Continuous grading is not necessary for obtaining a minimum of air voids

Answer

The omission of a certain size of aggregate is shown by a straight horizontal line on the grading curve

Answer

The omission of a certain size of aggregate in concrete increases the workability but also increases the liability to segregation

Question 4

The type of aggregates of same nominal size, which contain less voids when compacted, are

Accepted Answer

rounded spherical

Answer

irregulaf

Answer

flaky

Answer

none of these

Question 5

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

Accepted Answer

all the above

Answer

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

Answer

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

Answer

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

Question 6

Pick up the correct statement from the following :

Accepted Answer

Both A and B

Answer

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

Answer

The total water is the free water and the amount actually absorbed by the aggregates

Answer

Neither A nor B

Question 7

If the average compressive strength is 4000 kg/cm2 and standard deviation is 500, the co-efficient of variation is

Accepted Answer

125.00%

Answer

10%

Answer

15%

Answer

185.00%

Question 8

Batching error means inaccuracy in the quantity of

Accepted Answer

all the above

Answer

aggregates

Answer

cement

Answer

water

Question 9

Addition of pozzolana to ordinary port land cement, causes

Accepted Answer

all the above

Answer

decrease in early strength

Answer

reduction in chemical action with sulphates

Answer

increase in shrinkage