Building Material (GENERAL ENGINEERING) (SSC JE)

Total Questions: 50

11. Which of the following paints are essentially a dispersion of rubber like resin polystyrene and polyvinyl acetate in water and are prepared by grinding suitable pigments (titanium oxide) in an emulsion of water and film forming driver e.g. Co and Mn? [JSSC JE (GEN. ENGG.)-23.10.2022 ]

Correct Answer: (d) Plastic emulsion paint
Solution:Plastic emulsion paint (IS : 5411 Parts I and II)

• In the former case of emulsifying agents are sodium or ammonium soaps whereas in the later case metallic soaps of magnesium or zinc are used.

• Stabilizers such as proteins (dextrin, starch, casein) are added to impart chemical resistance to the emulsion.

• These paints should become surface dry within 15 minutes and hard dry within 4 hours and are alkali resistant.

• Plastic emulsion points are useful in porous and wet surface.

Rubber based paints–Rubber treated with chlorine gas is dissolved in solvent and desired pigment is added. These paints are resistant to acid, alkali and dampness. Rubber based paints are used over concrete and cement plastered surfaces.

12. What should be the percentage of Alumina in Good Brick Earth? [JSSC JE (GEN. ENGG.)-23.10.2022]

Correct Answer: (c) 20% - 30%
Solution:Composition of Good Brick Earth

• Properties of various ingredients is as below–

13. Consider the following methods of preservation of timber. [JSSC JE (GEN. ENGG.)-23.10.2022]

1. Pressure Application

2. Brush Application

3. Dipping

4. Open Tank

Then correct sequence of these methods in the increasing order of their effectiveness is :

Correct Answer: (c) 2, 3, 4, 1
Solution: Preservation of timber (IS : 401)

The durability of wood is decidely variable property. If well-seasoned and kept in dry place if immersed in water. Preservative treatment of timber is not support to improve its basic properties like mechanical, electrical or chemical properties.

 Methods of preservation of timiber in the increasing

1. Order of their effectiveness 

• Brush application (Surface application)

• Dipping (Soaking treatment)

• Open tank

• Pressure application

14. Moh's scale is used to measure which property of a stone? [NHPC JE (ME) 06.04.2022 (Shift-II) JPSC AE (GEN. ENGG)-2013]

For stones, Moh's scale is used to determine

Correct Answer: (b) hardness
Solution:Hardness– It is probably the most important properly for rapid determination of minerals. It is measured by scratching the mineral with a series of substance of known variation in hardness. It is determined by Moh's scale.

15. Match List-I (constituents of bricks) with List-II (corresponding influence) and select the correct answer using the code given below the Lists : [JPSC AE (GEN. ENGG)-2013 ]

List-I: Constituents of BricksList-II: Corresponding Influence
a. Alumina1. Colours brick
b. Silica2. Plasticity for moulding
c. Magnesia3. Reacts with silica during burning and causes particles to unite together and development of strength
d. Limestone4. Preserves the form of brick at high temperature and prevents shrinkage
Correct Answer: (c) a-2, b-4, c-1, d-3
Solution:Code:
ConstituentInfluence
AluminaPlasticity recovery for moulding
SilicaPreserves the form of brick at high temperature and prevents shrinkage
MagnesiaColours brick
LimestoneReacts with silica during burning and causes particles to unite together and development of strength

16. Which of the following IS code that gives the ceramic tile classification and characteristics? [JSSC JE (GEN. ENGG.)- 03.07.2022]

Correct Answer: (b) IS 13712 : 1993
Solution:IS 13712 : 1993 gives the ceramic tile classification and characteristics.

Ceramic tiles– Thin slabs made from clays silica fluxes, colouring and other minerals raw materials, generally used as coverings for floors walls or facades.

• They are prepared by grinding, sieving, mixing, moistering etc, and are shaped by pressing extruding casting or other processes, usually at room temperature.

17. What is the range of Iron oxide present in ordinary Portland cement? [JSSC JE (GEN. ENGG.)- 03.07.2022]

Correct Answer: (a) 0.5 – 6%
Solution:Ingredients present in ordinary Portland cement–

1. Calcium Oxide → 60 – 65%

2. Silica → 17 – 25%

3. Aluminium Oxide → 3 – 8%

4. Calcium Sulphate → 3 – 5%

5. Iron Oxide → 0.5 – 6%

6. Magnesium Oxide → 0.1– 4%

7. Sulphur trioxide → 1 – 3%

8. Alkalies → 0.5 – 1%

18. According to Moh's scale of hardness, the mineral with least hardness is : [JSSC JE (GEN. ENGG.)- 03.07.2022]

Correct Answer: (d) Talc
Solution:Moh's scale of hardness–

19. Which of the following is not a tool used for dressing stones? [JSSC JE (GEN. ENGG.)- 03.07.2022]

Correct Answer: (b) Mallet
Solution:Dressing of stone–Dressing of stone is performed to achieve following objectives–

1. To obtained desired appearance

2. To increase the properties of stone such as durability and strength.

3. To suit the requirement of stone masonry

4. To reduce the transportation and handling cost of stone.

5. Crow chisel for cutting of stone.

20. Which among the following is an incorrect option? [JSSC JE (GEN. ENGG.)- 03.07.2022]

Correct Answer: (d) Annular/Annual ring test/examine is used to determine the timber defects.
Solution:Pith–Pith is the innermost part of tree consist of cellular tissue which is used for nourishment of tree in young age.

Sap wood–It consist both living and dead cells.

• Sap wood is outer annual rings between heart wood and cambium layers, it is the living, outermost portion of a woody stem.

Cambium layer–Cambium layer is very thin layer of tissue between sapwood and inner bank.

• Cambium in plants, layer of actively dividing all between xylem (wood) and phloem (bast) that is responsible for the secondary growth of stems and roots.