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This set of Concrete Technology and Design Multiple Choice Questions & Answers (MCQs) focuses on Concrete Technology And Design Set 9
Q1 | Shrinkage in concrete can be reduced by using
- low water cement ratio
- less cement in the concrete
- proper concrete mix
- all the above
Q2 | The shuttering of a hall measuring 4 m × 5 m, can be removed after
- 5 days
- 7 days
- 10 days
- 14 days
Q3 | The approximate value of the ratio between direct tensile strength and flexural strength is
- 0.33
- 0.5
- 0.75
- 1.0
Q4 | An aggregate is said to be flaky if its least dimension is less than
- 1/5th of mean dimension
- 2/5th of mean dimension
- 3/5th of mean dimension
- 4/5th of mean dimension
Q5 | Workability improved by adding
- fly ash
- hydrated lime
- calcium chloride
- all the above
Q6 | Workability of concrete is inversely proportional to
- time of transit
- water-cement ratio
- the air in the mix
- size of aggregate
Q7 | Inert material of a cement concrete mix, is
- water
- cement
- aggregate
- none of these
Q8 | If a beam fails in bond, then its bond strength can be increased most economically by
- increasing the depth of beam
- using thinner bars but more in number
- using thicker bars but less in number
- providing vertical stirrups
Q9 | Pick up the incorrect statement from the following:
- a rich mix of concrete possesses higher strength than that a lean mix of desired workability with excessive quantity of water
- the strength of concrete decreases as the water cement ratio increases
- good compaction by mechanical vibrations, increases the strength of concrete
- none of these
Q10 | Ordinary Portland cement is manufactured from
- lime stone and clay
- gypsum and lime
- pozzolana
- lime, pozzolana and clay
Q11 | The percentage of reinforcement in case of slabs, when high strength deformed bars are used isnot less than
- 0.15
- 0.12
- 0.30
- 1.00
Q12 | Addition of pozzolana to cement
- decreases workability
- increases strength
- increases heat of hydration
- none of these
Q13 | If 50 kg of fine aggregates and 100 kg of coarse aggregates are mixed in a concrete whose watercement ratio is 0.6, the weight of water required for harsh mix, is
- 8 kg
- 10 kg
- 12 kg
- 14 kg
Q14 | The minimum cover to the ties or spirals should not be less than
- 15 mm
- 20 mm
- 25 mm
- 50 mm
Q15 | According to Water-Cement Ratio Law, the strength of workable plastic concrete
- depends upon the amount of water used in the mix
- does not depend upon the quality of cement mixed with aggregates
- does not depend upon the quantity of cement mixed with aggregates
- all the above
Q16 | Sands of zone I are:
- course
- medium
- medium to fine
- fine
Q17 | According to Whitney's theory, ultimate strain of concrete is assumed to be
- 0.03 %
- 0.1 %
- 0.3 %
- 3 %
Q18 | The condition not applicable to water cement ratio law, is
- internal moisture conditions on hydration continue till complete strength is gained
- concrete specimens may be tested at any temperature
- concrete specimens need be of same age
- concrete specimens need be of same size
Q19 | If the slump of a concrete mix is 60 mm, its workability is
- very low
- low
- medium
- high
Q20 | Cube strength of controlled concrete to be used for pre-tensioned and post-tensioned workrespectively should not be less than
- 35 mpa and 42 mpa
- 42 mpa and 35 mpa
- 42 mpa and 53 mpa
- 53 mpa and 42 mpa
Q21 | The void ratio of
- single size coarse aggregate is roughly 0.45
- graded coarse aggregate is roughly 0.040
- fine aggregate is roughly 0.45
- all the above
Q22 | According to IS : 382-1963, a good aggregate should be
- chemically inert
- sufficiently strong
- hard and durable
- all the above
Q23 | The compressive strength of 100 mm cube as compared to 150 mm cube is always
- less
- more
- equal
- none of the above
Q24 | The diameter of the Vicat plunger is 10 mm and its length varies from
- 20 mm to 30 mm
- 30 mm to 40 mm
- 40 mm to 50 mm
- 50 mm to 60 mm
Q25 | Gypsum is added for
- colour
- strength
- controlling setting time
- none of these