## Concrete Technology MCQ Practice Questions (Civil Eng) Set 3

##### Permissible compressive strength of M 300 concrete grade is:

Options are :

• 250 kg/cm^(2)
• 300 kg/cm^(2)
• 100 kg/cm^(2)
• 200 kg/cm^(2)
• 150 kg/cm^(2)

Options are :

• Sand stone
• Lime stone
• Slate
• Graphite

Options are :

• 5.5
• 7.5
• 6.5
• 4.5
• 8.5

##### Under normal conditions using an ordinary cement, the period of removal of the form work, is:

Options are :

• 7 days for beam soffits
• 21 days for bottom beams over 6 m spans
• 14 days for bottom slabs of spans 4.6 m and more
• 2 days for vertical sides of columns
• All the above

Answer :All the above

##### Proper proportioning of concrete, ensures:

Options are :

• Desired durability
• Desired strength and workability
• All the above
• Resistance to water
• Water tightness of the structure

Answer :All the above

##### To obtain cement dry powder, lime stones and shales or their slurry, is burnt in a rotary kiln at a temperature between:

Options are :

• 1100° and 1200°C
• 1500° and 1600°C
• 1300° and 1400°C
• 1200° and 1300°C
• 1400° and 1500°C

Answer :1400° and 1500°C

Options are :

• 7
• 6
• 4
• 5
• 3

##### For road pavements, the cement generally used, is:

Options are :

• None of these
• Ordinary Portland cement
• Low heat cement
• Blast furnace slag cement
• Rapid hardening cement

Answer :Rapid hardening cement

Options are :

• 7.5 cm
• 5.0 cm
• 10 cm
• 2.5 cm
• 15 cm

##### Internal friction between the ingredients of concrete, is decreased by using:

Options are :

• Rich mix
• Less water
• More water and coarse aggregates
• Fine aggregates
• None of these

Answer :More water and coarse aggregates

Options are :

• 15 kg/cm^(2)
• 10 kg/cm^(2)
• 5 kg/cm^(2)
• 8 kg/cm^(2)
• 12 kg/cm^(2)

Options are :

• 1800°C
• 1000°C
• 1200°C
• 1400°C
• 1600°C

##### Workability of concrete is measured by:

Options are :

• Talbot Richard test
• Vicat apparatus test
• Minimum void method
• Slump test

##### Curing a concrete for long period ensures better:

Options are :

• All the above
• Water resistance
• Volume stability
• Water tightness and durability
• Strength

Answer :All the above

Options are :

• 40%
• 30%
• 35%
• 20%
• 25%

##### The following proportion of the ingredients of concrete mix, is not in conformation to arbitrary method of proportioning:

Options are :

• 1 : 3 : 6
• 1 : 2 : 8
• 1 : 4 : 10
• 1 : 2 : 4
• 1 : 1 : 2

Answer :1 : 4 : 10

##### To ensure constant moisture content in aggregates:

Options are :

• All the above
• Height of each aggregate pile should not exceed 1.50 m
• Area of each aggregate pile should be large
• Conical heaps of aggregates should be avoided to prevent moisture variation
• Aggregate pile should be left for 24 hours before aggregates are used

Answer :All the above

##### Wp and Wf are the weights of a cylinder containing partially compacted and fully compacted concrete. If the compaction factor Larger image is 0.95, the workability of concrete is:

Options are :

• Very low
• None of these
• High
• Low
• Extremely low

##### Workability improved by adding:

Options are :

• Foaming agent
• Air-entraining agent
• All the above
• Aluminium compound
• Oily-agent

Answer :All the above

##### If 20 kg of coarse aggregate is sieved through 80 mm, 40 mm, 20 mm, 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 300 micron and 150 micron standard sieves and the weights retained are 0 kg, 2 kg, 8 kg, 6 kg, 4 kg respectively, the fineness modulus of the aggregate, is:

Options are :

• None of these
• 7.35
• 7.40
• 7.30
• 7.45

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

Options are :

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

Answer :All the above

##### The bulk density of aggregates does not depend upon:

Options are :

• Specific gravity of aggregates
• Grading of aggregates
• None of these
• Size and shape of aggregates
• Size and shape of the container

Answer :Size and shape of the container

##### After casting, an ordinary cement concrete on drying:

Options are :

• Expands
• None of these
• Shrinks
• Mix

##### M10 grade of concrete approximates:

Options are :

• 1 : 1.5 : 3 mix
• 1 : 1 : 2 mix
• 1 : 3 : 6 mix
• None of these
• 1 : 2 : 4 mix

Answer :1 : 3 : 6 mix

##### Transport of concrete by pumps, is done for a distance of:

Options are :

• 100 m
• 400 m
• 200 m
• None of these
• 300 m

##### M 150 grade of concrete approximates:

Options are :

• None of these
• 1 : 3 : 6 mix
• 1 : 2 : 4 mix
• 1 : 1 :2 mix
• 1 : 1.5 : 3 mix

Answer :1 : 1 :2 mix

##### Concrete mainly consists of:

Options are :

• Water
• Cement
• Aggregates
• All the above

Answer :All the above

##### Curing:

Options are :

• Prevents the loss of water by evaporation
• Reduces the shrinkage of concrete
• All of the above
• Preserves the properties of concrete

Answer :All of the above

##### The risk of segregation is more for:

Options are :

• All the above
• Wetter mix
• Larger proportion of maximum size aggregate

Answer :All the above

##### Pick up the correct proportions of chemical ingredients of cement:

Options are :

• Iron oxide : Alumina : Silica : Lime : 63 : 22 : 6 : 3
• Silica : Lime : Alumina : Iron oxide : 63 : 22 : 6 : 3
• Lime : Silica : Alumina : Iron oxide : 63 : 22 : 6 : 3
• Alumina : Silica : Lime : Iron oxide : 63 : 22 : 6 : 3

Answer :Lime : Silica : Alumina : Iron oxide : 63 : 22 : 6 : 3

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