250+ TOP MCQs on Testing of Aggregates and Answers

Concrete Technology Multiple Choice Questions on “Testing of Aggregates”.

1. In crushing test, dry aggregates passing through ________ mm sieve and retained ________ mm in a cylinder.
a) 12.5, 10
b) 11.5, 10
c) 12.5, 11.5
d) 10, 2.36
Answer: a
Clarification: Dry aggregates passing through 12.5 mm sieves and retained 10 mm sieves are filled in a cylindrical measure of 11.5 mm diameter and 18 cm height in three layers.

2. According to IS: 2386 part-IV, each layer is tamped ________ times in crushing test.
a) 20
b) 25
c) 30
d) 10
Answer: b
Clarification: Each layer is tamped 25 times with at standard tamping rod. The test sample is weighed and placed in the test cylinder in three layers each layer being tamped again.

3. A value less than 10 signifies an exceptionally _________ while above 35 would normally be regarded as _________
a) Strong aggregates, weak aggregates
b) Weak aggregates, strong aggregates
c) Strong aggregates, strong aggregates
d) Weak aggregates, weak aggregates
Answer: a
Clarification: A value less than 10 signifies an exceptionally strong aggregate while above 35 would normally be regarded as weak aggregates.

4. Los Angeles machine consists of circular drum of internal diameter ________ mm and length ________ mm.
a) 700, 700
b) 520, 520
c) 520, 700
d) 700, 520
Answer: d
Clarification: Los Angeles machine consists of circular drum of internal diameter 700 mm and length 520 mm mounted on horizontal axis enabling it to be rotated.

5. Which machine is preferred for abrasion test?
a) Vicat’s mould
b) Los Angeles
c) Flakiness Gauge
d) Elongation Gauge
Answer: b
Clarification: Los Angeles is preffered for abrasion test for carrying out the hardness property and has been standardized in India.

6. A maximum value of _________ percent is allowed for WBM base course in Indian conditions.
a) 25
b) 35
c) 40
d) 50
Answer: c
Clarification: The aggregate crushing value provides a relative measure of a maximum value of 40%age is allowed for WBM base course in Indian conditions.

7. Aggregates to be used for wearing course, the impact value shouldn’t exceed ________ percent.
a) 30
b) 35
c) 40
d) 25
Answer: a
Clarification: Aggregates to be used for wearing course, the impact value shouldn’t exceed 30 %. For bituminous macadam the maximum permissible value is 35 %.

8. What is the range of water absorption of aggregates used in road?
a) 2.5-2.9
b) .1-2
c) .1-2.5
d) 2-2.9
Answer: b
Clarification: The specific gravity of aggregates normally used in road ranges from about 2.5 to 2.9. Water absorption values range from 0.1 to about 2.0 percent for aggregates normally used in road surfacing.

9. The loss in weight should not exceed ______________ percent when tested with sodium sulphate and ________ percent with magnesium sulphate solution.
a) 12, 18
b) 18, 12
c) 10, 15
d) 15, 10
Answer: a
Clarification: The loss in weight should not exceed 12 percent when tested with sodium sulphate and 18 percent with magnesium sulphate solution.

10. If 60% aggregates doesn’t pass through the 2.36mm sieve, then what would be the value of Aggregate impact value?
a) 60%
b) 40%
c) 25%
d) 100%
Answer: b
Clarification: Aggregate impact value = (W1/W2)*100
= {(100-60)/100} * 100
= 40%.