Concrete Technology Sheet 4
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1) Question.
Steam curing is not recommended for use with
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2) Question.
Which of the following types of concrete mixers is most commonly used in precast concrete factories ?
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3) Question.
In concrete mix design, allowance for surface water carried by aggregate is necessary in case of
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4) Question.
In concrete mix design, allowance for bulking of sand is necessary in case of
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5) Question.
Addition of sugar in concrete ( about 0.05% of weight of cement) results in
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6) Question.
Reduction in the quantity of mixing water which is possible by the use of plasticizers and admixtures varies from
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7) Question.
The Indian Standards recommend the use of calcium chloride as accelerating admixture in
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8) Question.
The presence of entrained air in concrete results in
i) reducing bleeding
ii) lowering density of concrete
iii) decreasing strength at all ages
The correct answer is
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9) Question.
For a satisfactory workable concrete with a constant water-cement ratio, increase in aggregate cement
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10) Question.
According to Indian Standards, the increase in compressive strength of high alumina cement concrete at 6 months, beyond 28 days compressive strength is,
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11) Question.
Select the incorrect statement
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12) Question.
If the compacting factor of a concrete is 0.90, then the workability according to Indian Standards is
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13) Question.
The value of Vee-Bee time for low workability as per Indian Standards is prescribed as
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14) Question.
Which of the following workability tests is most suitable for concrete of very low workability?
i) slump test
ii) compacting factor test
iii) Vee-Bee test
The correct answer is
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15) Question.
Workability of concrete increase by
i) increasing the water content
ii) increasing the temperature
iii) increasing the use of flaky and elongated aggregates
The correct answer is
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16) Question.
For a constant water-cement ratio, decrease in aggregate-cement ratio causes
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17) Question.
According to Indian Standards, the limit of loss on ignition for ordinary portland cement is
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18) Question.
According to Indian Standards, the pozzolona content in portland pozzolona cement is
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19) Question.
According to Indian Standards, the minimum 7 days compressive strengths of ordinary Portland cement and portland pozzolana cement in N/mm^2 are reapectively
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20) Question.
Maximum permissible limit of magnesia content in ordinary Portland cement is
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