1. The Indian standard code specifies that the crushing strength for which the mix should be designed in the laboratory should be ................... the strength actually required ?

1.25

1.5

2

2.5

Answer: 1.25

Explanation:


2. Which of the following grade is not recommended by IS 456-1978 ?

M 10

M 55

M 20

M 40

Answer: M 55

Explanation:


3. The steel mould used for slump test is in the form of a ?

cube

cylinder

frustrum of a cone

none of these

Answer: frustrum of a cone

Explanation:


4. For the improvement of workability of concrete, the shape of aggregate recommended is ?

irregular

angular

round

flaky

Answer: round

Explanation:


5. The standard sand now used in India is obtained from ?

Ennore (Chennai)

Mumbai

Orissa

Jaipur

Answer: Ennore (Chennai)

Explanation:


6. For reinforced concrete, the aggregate used is ?

sand

gravel

crushed rock

all of these

Answer: all of these

Explanation:


7. A moist aggregate is one ?

whose all the pores are filled with water and also having its surface wet

whose all the pores are filled with water but having its surface dry

which do not contain any moisture either in the pores or on the surface

which may contain some moisture in the pores but having dry surface

Answer: whose all the pores are filled with water and also having its surface wet

Explanation:


8. The value of fineness modulus for fine sand may range between ?

1.1 to 1.3

1.3 to 1.6

1.6 to 2.2

2.2 to 2.6

Answer: 2.2 to 2.6

Explanation:


9. Water cement ratio may be defined as the ratio of ?

mass of water to that of cement in a concrete mix

weight of water to that of cement in a concrete mix

volume of water to that of concrete in a concrete mix

weight of water to that of concrete in a concrete mix

Answer: weight of water to that of cement in a concrete mix

Explanation:


10. Hydration of cement is due to the chemical action of water with ?

dicalcium silicate

tricalcium silicate

tricalcium aluminate

all of these

Answer: all of these

Explanation: