This set of Repair and Rehabilitation of Structures Multiple Choice Questions & Answers (MCQs) focuses on “Sources of Dampness”.
1. Which of these are the internal sources of dampness?
a) Ground water
b) Flooding
c) Hygroscopic salts
d) Condensation
View Answer
Explanation: Water vapor which is generated during breathing, cooking and washing gets condensed on the cold surface all through the building leading to the wetting of the building and so it the internal source of dampness. Remaining sources are external sources of building.
2. Which of these are the external sources of dampness?
a) Construction moisture
b) Leaking services
c) Condensation
d) Precipitation
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Explanation: Naturally occurring rain and snow are the principal moisture sources which result in the penetration of water into the building and so it is the external sources of dampness. Remaining sources are internal sources of building.
3. The moisture from ground rises through _________ and affects the materials within the building.
a) capillary action
b) gravitational effect
c) pores
d) intermediate spaces
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Explanation: All the water reaching the ground are stored below and due to capillary action accompanied by the adhesion and cohesion of the particles the water starts to rise through the building leading to dampness.
4. Which of the following are the reason why flooding causes dampness?
a) Capillary action
b) Evaporation
c) Poor drainage
d) Improper joints
View Answer
Explanation: When flooding occurs then the water must be properly drained to avoid stagnation. When poor drainage prevails then the water starts to enter the building leading to dampness of the structure.
5. Hygroscopic salts are naturally occurring salts within the building material.
a) True
b) False
View Answer
Explanation: Hygroscopic salts naturally absorb the moisture from the air and thereby giving rise to localized patches which gives the impression of fabric on the fabric and it doesn’t penetrate the thickness of the building.
6. Percolation of water through roof covering doesn’t cause dampness.
a) True
b) False
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Explanation: In case when proper eave gutters and eave courses are not provided then the water that falls on the roof covering may enter the building through the faulty provisions leading to the dampness of the structure.
7. Which of the following alkali metals causes dampness?
a) Sodium chloride
b) Sodium carbonate
c) Magnesium chloride
d) Magnesium carbonate
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Explanation: The presence of sodium chloride salts in the water that is used for construction leads to the penetration of these salts and water into the building thereby causing dampness of the structure.
8. Drainage system for buildings that are constructed in low lying areas are good.
a) True
b) False
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Explanation: When the drainage system for the buildings are constructed in the low lying areas it causes water stagnation which in turn allows the penetration of water into the buildings leading to the dampness of the building.
9. Atmospheric sources of dampness cause deterioration of electrical installations.
a) True
b) False
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Explanation: The atmospheric sources of dampness lead to the corrosion of rebars that are used in the construction of structural elements thereby leading to the deterioration of electrical installations.
10. Which of the following are the victims of dampness?
a) Parapet wall
b) Panel walls
c) Shear walls
d) Main walls
View Answer
Explanation: During heavy showers the rain water descends down the parapet wall which results in the penetration of moisture into the building leading to the victims of dampness.
11. Which of the following are the victims of dampness?
a) Parapet wall
b) Panel walls
c) Shear walls
d) Main walls
View Answer
Explanation: During heavy showers the rain water descends down the parapet wall which results in the penetration of moisture into the building leading to the victims of dampness.
12. Which of the following is the primary cause of dampness?
a) Faulty construction or bad workmanship
b) Condensation
c) Rising dampness
d) Heavy rain showers
View Answer
Explanation: When the provisions are not provided as per the specifications then it is the result of faulty construction or workmanship i.e. when the thickness of the damp proof course is not provided as per the provision then it causes the penetration of moisture.
Sanfoundry Global Education & Learning Series – Repair and Rehabilitation of Structures.
To practice all areas of Repair and Rehabilitation of Structures, here is complete set of Multiple Choice Questions and Answers.
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