1. According to IS: 269-1976, the requirement of an ordinary Portland cement is that ?

the residue does not exceed 10% when sieved through IS sieve No. 9

its expansion is not more than 10 mm for unrated cement

its initial setting time is not less than 30 minutes

all of the above

Answer: all of the above

Explanation:


2. A compaction factor of 0.88 indicates that the workability of concrete mix is ?

very low

low

medium

high

Answer: medium

Explanation:


3. Blast furnace slag cement is used for ?

dams

bridge abutments

retaining walls

all of these

Answer: all of these

Explanation:


4. If 30% excess water is added, the strength of concrete is reduced by ?

30%

40%

50%

60%

Answer: 50%

Explanation:


5. Which of the following ingredient of cement when added in excess quantity, causes the cement set slowly ?

Lime

Silica

alumina

iron oxide

Answer: Silica

Explanation:


6. The controlled concrete is used for ?

one grade of concrete mix

three grades of concrete mix

five grades of concrete mix

all the seven grades of concrete mix

Answer: all the seven grades of concrete mix

Explanation:


7. Which of the following statement is wrong ?

The concrete can not be pumped

The concrete should have maximum creep

The concrete structures can be put to use immediately after their construction

all of the above

Answer: all of the above

Explanation:


8. The correct proportioning various ingredients of concrete largely depends upon ?

bulking of sand

water content

absorption

all of these

Answer: all of these

Explanation:


9. For compacting large sections of mass concrete in structures, the type of vibrator used is ?

internal vibrator

screed vibrator

form vibrator

all of these

Answer: internal vibrator

Explanation:


10. In lime concrete, lime is used as ?

coarse aggregate

fine aggregate

binding material

admixture

Answer: binding material

Explanation: