| 1. | The process of hardening the concrete mixes by keeping its surface moist for a certain period called ? | |
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floating
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curing
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screeding
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none of these
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Report Question| 2. | The minimum quantity of cement to be used in controlled concrete is specified as ? | |
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120 kg/cm³
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160 kg/cm³
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220 kg/cm²
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280 kg/cm²
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| 3. | For compacting plain concrete or one-way reinforced concrete floors, the vibrator used is ? | |
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internal vibrator
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screed vibrator
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form vibrator
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all of these
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| 4. | The compressive strength of an ordinary Portland cement (1:3 cement mortar cube) after 7 days test should not be less than ? | |
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11 N/mm²
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17.5 N/mm²
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22 N/mm²
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27 N/mm²
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| 5. | The workability of concrete by slump test is expressed as ? | |
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minutes
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mm/h
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mm²/h
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mm
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| 6. | To perform the initial setting time test, the water is added to the cement at the rate of .............. by weight of cement ? | |
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0.72 P
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0.78 P
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0.85 P
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0.95 P
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| 7. | To prevent segregation, the concrete should not be thrown from a height of more than ? | |
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1/2 m
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1 m
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1.5 m
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2 m
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| 8. | To perform the compressive strength test of cement, water is added at the rate of ? | |
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0.72 P+ 3% of water
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0.85 P+ 4% of water
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P+ 3% of water
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P+ 4% of water
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| 9. | The concrete mix of grade M 25 means that the compressive strength of 15 cm cubes at 28 days after mixing is ? | |
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15 N/mm²
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20 N/mm²
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25 N/mm²
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30 N/mm²
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