This set of Concrete Technology Multiple Choice Questions & Answers (MCQs) focuses on “Water Proofing Admixtures”.
1. What is water proofing admixtures?
a) Water repellent materials
b) Water fair material
c) Water absorption material
d) Water adsorption material
View Answer
Explanation: Water proofing admixtures are available in powder, paste or liquid form and may consist of pore filling or water repellent materials.
2. “Water proofing admixtures are available in powder, paste or liquid and gaesous form”. Is this statement true or false?
a) True
b) False
View Answer
Explanation: Water proofing admixtures are available in powder, paste or liquid form. It won’t be available un gaseous form.
3. Which one is not a chemically active pore filling material?
a) Silicate of soda
b) Aluminium
c) Chalk
d) Zinc
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Explanation: Chemically active pore filling materials: silicate of soda, aluminium, zinc sulphates and calcium chloride.
4. Which one is not a chemically inactive pore filling material?
a) Aluminium
b) Chalk
c) Talc
d) Fullers earth
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Explanation: Chemically inactive filling material: chalk, fullers earth and talc. And aluminium is active filling material.
5. Chemically active pore fillers __________ the setting of concrete.
a) Retards
b) Decrease
c) Accelerates
d) No change
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Explanation: Chemically active pore fillers accelerates the setting of concrete and thus render the concrete more impervious at early age.
6. Chemically inactive pore fillers __________ the workability.
a) Decrease
b) Increase
c) Don’t affect
d) Improve
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Explanation: Chemically inactive pore fillers improve the workability and to facilitate the reduction of water for given workability and to make dense concrete which is basically impervious.
7. “Water repelling materials like soda, potash soaps, etc make the concrete pervious”. Is this statement true or false?
a) True
b) False
View Answer
Explanation: Water repelling materials like soda, potash soaps, calcium soaps, waxes, fats, vegetable oils repel water and make the concrete impervious.
8. Nomenclature of water proofing agent.
a) PC
b) KIM
c) PCKIM
d) WP
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Explanation: Nomenclature of water proofing agent is KIM and PC is the nomenclature of Portland Cement.
9. The addition of the admixture to the mix __________ the surface tension.
a) Lowers
b) Higher
c) Don’t affect
d) No change
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Explanation: The addition of the admixture to the mix lowers the surface tension of the water thereby assisting in the formation of bubbles.
10. Entrapped air normally exists in the form of relatively __________ air voids.
a) Small
b) Absent
c) Large
d) Medium
View Answer
Explanation: Entrapped air normally exists in the form of relatively large air voids, which are not dispersed uniformly throughout the mix, entrained air exists in the form of minute disconnected bubbles well distributed throughout the mix.
Sanfoundry Global Education & Learning Series – Concrete Technology.
To practice all areas of Concrete Technology, here is complete set of 1000+ Multiple Choice Questions and Answers.