Concrete Technology Questions and Answers – Permeability

This set of Concrete Technology Multiple Choice Questions & Answers (MCQs) focuses on “Permeability”.

1. The addition of a pozzolanic admixture such as fly ash reduces the ____________
a) C3S
b) C3A
c) C2S
d) C4AF
View Answer

Answer: b
Explanation: The addition of a pozzolanic admixture such as fly ash reduces the C3A content of cement.

2. Lowering of ____________ might also help, since this would reduce the amount of CH that forms.
a) C3S
b) C3A
c) C2S
d) C4AF
View Answer

Answer: a
Explanation: Lowering of C3S might also help, since this would reduce the amount of CH that forms.

3. When the ____________ content is low, most ettringite will be formed in the plastic state.
a) C3SS
b) C3AA
c) C2S
d) C4AF
View Answer

Answer: b
Explanation: When the C3A content is low, most ettringite will be formed in the plastic state.
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4. The philosophy of prescribing low ____________ cement to improve resistance to sulphate attack.
a) C3S
b) C3A
c) C2S
d) C4AF
View Answer

Answer: b
Explanation: The philosophy of prescribing low C3A cement to improve resistance to sulphate attack hinges on the need to minimize ettringite formation after the concrete hardens.

5. The quality of concrete, specifically a ____________ permeability, is the best protection against sulphate attack.
a) High
b) Medium
c) Low
d) Very low
View Answer

Answer: c
Explanation: The quality of concrete, specifically a low permeability, is the best protection against sulphate attack.
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6. For concrete exposed to a very aggressive environment the w/c should be lower than __________
a) 1
b) .5
c) .4
d) .8
View Answer

Answer: c
Explanation: Higher is the aggressiveness of the environment lower should be the w/c ratio. For concrete exposed to a very aggressive environment, the w/c should be lower than 0.40.

7. The quality of concrete, specifically a ____________ w/c ratio, is the best protection against sulphate attack.
a) High
b) Medium
c) Low
d) Very low
View Answer

Answer: c
Explanation: The quality of concrete, specifically a low w/c ratio, is the best protection against sulphate attack.

8. The quality of concrete, specifically a ____________ cement content, is the best protection against sulphate attack.
a) High
b) Medium
c) Low
d) Very low
View Answer

Answer: a
Explanation: The quality of concrete, specifically a high cement content, is the best protection against sulphate attack.

9. Concentration of water-soluble sulphates in water ___________ ppm for mild exposure.
a) <150
b) 150-1500
c) 150-10000
d) >10000
View Answer

Answer: a
Explanation: Concentration of water-soluble sulphates in water less than 150 ppm for mild exposure.

10. Concentration of water-soluble sulphates in water ___________ ppm for severe exposure.
a) <150
b) 150-1500
c) 150-10000
d) >10000
View Answer

Answer: c
Explanation: Concentration of water-soluble sulphates in water 150-10000 ppm for severe exposure.

Sanfoundry Global Education & Learning Series – Concrete Technology.

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To practice all areas of Concrete Technology, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia - Founder & CTO at Sanfoundry
I’m Manish - Founder and CTO at Sanfoundry. I’ve been working in tech for over 25 years, with deep focus on Linux kernel, SAN technologies, Advanced C, Full Stack and Scalable website designs.

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