250+ TOP MCQs on Plasticizers and Answers

Concrete Technology Multiple Choice Questions on “Plasticizers”.

1. What are plasticizers?
a) Which adds water for workability
b) Which reduces water for workability
c) Which decreases workability at the same water content
d) Which oxidizes water for workability
Answer: b
Clarification: The organic substances or combinations of organic and inorganic substances, which allow a reduction in water content for the given workability, or give higher workability at the same water content.

2. Which one is an anionic surfactants?
a) Polyglycol esters
b) Hydroxylated carboxylic acids
c) Lignosulphonates
d) Carbohydrates
Answer: c
Clarification: Anionic surfactants such as lignosulphonates and their modifications and derivatives, salts of sulphonates hydrocarbons.

3. What is the amount used of plasticizers in cement by weight?
a) 0
b) .1-.4%
c) 1%
d) 1-2%
Answer: b
Clarification: Plasticizers are used in the amount of 0.1 percentage to 0.4 percentage by weight of cement.

4. What is the limitation of plasticizers?
a) A good plasticizer is one which does not cause air-entrainment in concrete > .1-.2%
b) A good plasticizer is one which does not cause air-entrainment in concrete > 5%
c) A good plasticizer is one which does not cause air-entrainment in concrete > 10-20%
d) A good plasticizer is one which does not cause air-entrainment in concrete > 1-2%
Answer: d
Clarification: A good plasticizer is one which does not cause air-entrainment in concrete is greater than 1-2%.

5. At constant workability, what is the reduction in mixing water?
a) 1-2%
b) 50%
c) .1-.4%
d) 5-15%
Answer: d
Clarification: At constant workability, the reduction in mixing water is expected to be of the order of 5% to 15%.

6. Where do we use plasticizers?
a) Where low degree of workability is required
b) Where medium degree of workability is required
c) Where high degree of workability is required
d) Where very low degree of workability is required
Answer: c
Clarification: Where low degree of workability is required like Deep beams, column and beam junctions.

7. What is super plasticizers?
a) Which adds water for workability
b) Which reduces high range of water for workability
c) Which decreases workability at the same water content
d) Which oxidizes water for workability
Answer: b
Clarification: The organic substances or combinations of organic and inorganic substances, which allow a high reduction in water content for the given workability at the same water content.

8. What is the allowed reduction of water with super plasticizers without reducing workability?
a) 10%
b) 20%
c) 30%
d) 40%
Answer: c
Clarification: Super plasticizers permits reduction of water content about 30% without reducing the workability.

9. Is it possible to use w/c ratio as low as 5?
a) Yes
b) No
Answer: b
Clarification: It is possible to use w/c ratio as low as 0.25 or even lower and yet to make flowing concrete to obtain strength of order 120Mpa or more.

10. What is the limitation of Carboxylic acids in High range water reducers?
a) 0
b) .1%
c) .2%
d) .3%
Answer: b
Clarification: It is the standard value of limitation of Carboxylic acids in High range water reducers i.e. 0.1 percentage.