This set of Repair and Rehabilitation of Structures Multiple Choice Questions & Answers (MCQs) focuses on “Materials for Damp Proof Course – Set 2”.
1. In the case of damp and humid atmosphere, the concrete containing richer mix should be used as DPC.
a) True
b) False
View Answer
Explanation: When the DPC is to be laid in humid and damp condition then the usage of concrete with richer mix should be used to tolerate the humid condition thereby avoiding the penetration of water in to the building.
2. Which of the following DPC material comes under the flexible type?
a) Mastic asphalts
b) Slates
c) Stones
d) Bitumen felts
View Answer
Explanation: Bitumen felts comes under a flexible type of DPC material because that have good flexible nature to contract and expand during the temperature changes and also it is flexible enough to be laid over a large area.
3. Which of the following DPC material comes under the semi rigid type?
a) Mastic asphalt
b) Slates
c) Stones
d) Plastic sheeting
View Answer
Explanation: Mastic asphalts comes under semi rigid type of DPC material because they are rigid enough to hold the load acting on them and are mainly used at the bottom of load bearing walls rather than partition walls.
4. Which of the following DPC material comes under the rigid type?
a) Mastic asphalt
b) Slates
c) Slurry
d) Plastic sheeting
View Answer
Explanation: Slate comes under rigid type of DPC material because they are very rigid to withstand greater loads acting on them and also they are used in places where the rising dampness is heavy since they are strong enough to arrest the moisture penetration.
5. The flexible hot bitumen used as DPC should be laid to a thickness of _______
a) 5 mm
b) 3 mm
c) 10 mm
d) 15 mm
View Answer
Explanation: The flexible hot bitumen which is used as DPC is often used on the bedding of concrete or mortar to a thickness of 3mm.
6. When bituminous felts are used as DPC an overlap of ________ is provided at joints.
a) 105 mm
b) 130 mm
c) 100mm
d) 150 mm
View Answer
Explanation: When bituminous felts are used as DPC an overlap of 100 mm is provided at joints so that the material does not leak from the surface in which it is laid and also full overlap is provided at corners so that it does not squeeze under high pressure.
7. When metal sheets such as lead sheets are used as DPC then the thickness of the sheets should be such that the weight is less than _________ N/m2.
a) 100
b) 200
c) 400
d) 150
View Answer
Explanation: When metal sheets such as lead sheets are used as DPC then the thickness of the sheets should be such that the weight is less than 200 N/m2 so that it does not squeeze under ordinary pressure and also it becomes highly impervious.
8. When bricks are used as DPC then the water absorbing capacity of such bricks should be less the ____ % of their weight.
a) 2.5
b) 4.5
c) 10.5
d) 10
View Answer
Explanation: When bricks are used as DPC then the water absorbing capacity of such bricks should be less the 4.5% of their weight and such bricks are widely used when the DPC is to be inserted in an existing structure. They mainly adopted in places where dampness is not excessive.
9. DPC is laid over large area then it is better for flexible materials.
a) True
b) False
View Answer
Explanation: Flexible materials have good bonding and also provide lesser number of joints and so it is preferred over large areas where DPC is to be laid.
10. When mortar is used as DPC then lime is used to decrease the workability.
a) True
b) False
View Answer
Explanation: When mortar is used as DPC then lime is used to increase the workability so that it can be spread to wide area to provide damp proofing to the building.
11. The places where differential thermal movements occur ________ materials are to be used.
a) flexible
b) rigid
c) semi rigid
d) slurry
View Answer
Explanation: In the places where differential thermal movements occur then flexible materials are to be used in order to compensate for the differential thermal movements that occur between the materials.
12. ____________ base causes damage to DPC that is laid.
a) even
b) uneven
c) rigid
d) flexible
View Answer
Explanation: Uneven base causes damage to DPC that is laid due to the dimensional instability of the DPC thereby leading to the breakage in the DPC which in turn causes water penetration into the building.
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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