Miscellaneous Material MCQ Quiz - Objective Question with Answer for Miscellaneous Material - Download Free PDF

Explanation:

Quartz: It is one of the rock-forming siliceous minerals.

Quartz features great strength, hardness, and resistance to chemical attack.

Gypsum has poor strength and readily soak in water.

Mica displays a great tendency to cleavage and split readily along one or several directions.

Explanation:

In half-round country tiles, the tiles are laid in pairs known as:

• Under tile: The tile placed beneath, which serves as the foundation for the overlapping tiles above.

• Over tile: The tile placed on top, which covers the under tile and forms the final protective layer of the roof.

This arrangement ensures proper water shedding and adds to the durability and aesthetic of the roof.

Additional Information Key Characteristics of Half-Round Country Tiles:

1. Shape:

   • These tiles are typically half-cylinder-shaped, with a smooth, curved surface.

   • The semi-circular shape helps in efficiently draining water from the roof surface.

2. Materials:

   • They are often made from clay or concrete, with clay being the traditional material.

   • In some cases, they can also be made from ceramic for better aesthetic appeal.

3. Installation:

   • The tiles are laid in an overlapping pattern, where each tile partially covers the one beneath it.

   • Tiles are laid in pairs called under tile and over tile (as discussed earlier). The under tile is placed first, followed by the over tile.

4. Advantages:

   • The half-round shape allows for effective rainwater drainage, making them ideal for areas with heavy rainfall.

   • They are durable and have a long lifespan if properly maintained.

   • The shape offers a traditional and rustic look, making them popular in heritage-style buildings or cottages.

   • They offer good ventilation due to the gaps created by the curved tiles, which helps in reducing heat buildup.

5. Disadvantages:

   • These tiles can be fragile and may break or crack under heavy impact.

   • Installation can be more labor-intensive and requires a skilled workforce, as precise alignment is needed.

   • Cost can be higher than some modern roofing options due to material and installation requirements.

Explanation:

Pestle:

• A pestle is typically used in the process of grinding or crushing materials, such as in a mortar and pestle setup. It is not used for stone dressing.

Additional Information

1. Splitting Chisel: This tool is used in stone dressing to split large stones into smaller pieces by creating cracks along predetermined lines.

2. Mash Hammer: A mash hammer is used to shape and dress stones by striking them in a controlled manner.

3. Dressing Knife: This is used to smooth and finish the stone's surface by carving or scraping it into the desired shape.

Explanation:

Slate Tile

1. Material: Slate tiles are made from natural stone, specifically slate rock. The stone is typically mined from quarries, then processed into thin, flat tiles for roofing.

2. Durability: Slate is extremely durable and long-lasting, with a lifespan that can exceed 100 years if properly maintained. It is resistant to weathering, including harsh rain, snow, and high temperatures.

3. Aesthetic Appeal: Slate tiles are available in a range of colors, including grey, green, black, purple, and red. Their natural texture and color variations provide a unique, elegant look to roofs.

4. Water Resistance: One of the key advantages of slate tiles is their ability to resist water penetration, making them ideal for roofing applications in areas with heavy rainfall.

5. Fire Resistance: Slate is naturally fire-resistant, adding an extra layer of safety to buildings with slate roofing.

 Additional Information

Types of tiles:

1. Clay Tiles:

   • Made from fired natural clay.

   • Commonly used in Mediterranean, Spanish, and Southwestern-style homes.

   • Durable, weather-resistant, and often reddish-brown or terracotta in color.

   • Requires a sturdy roof structure due to weight.

2. Concrete Tiles:

   • Made from cement, sand, and water.

   • Lightweight and versatile, available in different shapes and styles.

   • Durable, fire-resistant, and affordable compared to clay tiles.

   • Prone to cracking under extreme conditions.

3. Metal Tiles:

   • Made from aluminum, steel, copper, or zinc.

   • Lightweight, durable, and fire-resistant.

   • Often used for modern, industrial, or eco-friendly designs.

   • Excellent for shedding rain and snow but prone to dents and corrosion.

4. Asphalt Shingles:

   • Made from fiberglass or organic material coated with asphalt.

   • Most common roofing material due to affordability and ease of installation.

   • Comes in a variety of colors and styles.

   • Less durable than slate or clay tiles but more affordable.

5. Wooden Tiles:

   • Made from natural wood, often cedar or redwood.

   • Provides a rustic and aesthetic look.

   • Susceptible to fire, rot, and insect damage, requiring regular maintenance.

   • Used in traditional or environmentally conscious homes.

6. Vinyl Tiles:

   • Made from PVC (polyvinyl chloride) plastic.

   • Used mostly for flooring, not roofing.

   • Affordable, easy to install, and low maintenance.

   • Available in various patterns and designs, mimicking wood, stone, or ceramic.

7. Ceramic Tiles:

   • Made from clay and fired at high temperatures.

   • Common for flooring, walls, and sometimes roofs.

   • Resistant to moisture, easy to clean, and available in various styles and colors.

   • Durable but can crack under heavy impact.

8. Porcelain Tiles:

   • A subtype of ceramic tiles, denser and harder.

   • Extremely durable and water-resistant, making them ideal for wet areas.

   • Used for both floors and walls in residential and commercial settings.

9. Terracotta Tiles:

   • Made from natural clay fired at high temperatures.

   • Known for earthy, reddish hues and rustic appearance.

   • Often used in Mediterranean and traditional architecture.

   • Requires sealing for durability and water resistance.

10. Glass Tiles:

    • Made from glass, offering a modern, shiny appearance.

    • Often used for decorative purposes, especially in backsplashes and bathrooms.

    • Easy to clean but may chip or crack if not installed carefully.

Explanation:

1. A pickaxe is specifically designed for breaking hard surfaces during excavation.
2. It has a pointed end that allows workers to break through tough materials such as rock, concrete, or compacted soil.
3. It is commonly used in construction and mining for digging and breaking up hard surfaces.

 Additional Information

Crowbar: A crowbar is a tool used for levering, prying, and pulling objects apart. It is not designed specifically for breaking hard surfaces, though it may assist in other aspects of excavation.

Rake: A rake is generally used for gathering, spreading, or leveling materials like soil, gravel, or leaves. It is not intended for breaking hard surfaces.

Spade: A spade is a digging tool with a flat blade, primarily used for cutting through soil, sod, or loose dirt. It is not ideal for breaking through hard surfaces like rock or concrete.

Concept:

Impact test:

Impact test is used to determining the toughness of stone, it is performed in an Impact Test Machine as followed:

1. A cylinder of diameter 25mm and height 25mm is taken out from the sample of stones.
2. It is then placed on the cast iron anvil of the machine.
3. A steel hammer of weight 20N is allowed to fall axially in a vertical direction over the specimen.
4. The height of the first blow is 1 cm, that of the second blow is 2 cm, that of the third blow is 3 cm, and so on.
5. Blow at which specimen breaks is noted. If it is an nth blow, ‘n’ represents the toughness index of stone.

Explanation:

Slaking is the process in which quick lime reacts with water, during this reaction, it swells, cracks, and falls out as calcium hydroxide.

\(\underbrace {CaO}_{\begin{array}{*{20}{c}} {Quick} \\ {lime} \end{array}} + {H_2}O\xrightarrow{{Slaking}}\underbrace {Ca{{\left( {OH} \right)}_2}}_{\begin{array}{*{20}{c}} {Hydrate} \\ {lime} \end{array}} + Heat\)

Explanation:

Characteristics of good building stones are:

• Compressive strength > 1000 kg/cm2 or 100 N/mm2
• High durability and coefficient of hardness > 14
• Stones should be well seasoned before putting into use.
• Specific gravity > 2.7
• Toughness Index > 13
• Low water absorption

Explanation:

(i) The process of giving a proper size, shape, and finish to the roughly broken stones as obtained from the quarry is known as “Dressing of stone” and is carried out for the following purposes:

• To get the desired appearance from stone work.
• to make the transport from quarry easy and economical.
• to suit to the requirements of stone masonry.
• to take advantage of local mean near quarry who are trained for such type of work, etc.

(ii) The process of extraction of suitable stones from their natural rock beds or layers is commonly called Quarrying of Stones

(iii) Stones obtained from the quarries are very rough and irregular in shape and quite bulky in size and weight

(iv) The dressing of stone is done immediately after quarrying.

(v) Seasoning of stone means removal of moisture from stone. seasoning is performed by placing the stones in sundried conditions.

Explanation:

Asbestos is natural mineral, which consists of silicate of calcium and magnesium found in the form of very thin fibres.

Characteristics of Asbestos:

• They are light in weight and fire-resistant.
• It has low water permeability hence less porous.
• It is brown, grey, and white in colour.
• It is resistant to acids and alkalis.
• Its specific gravity is 3.10.
• It has excellent heat and electric insulation.
• They do not require any protective paint.
• Asbestos cement is widely used in the manufacturing of roofing slates and tiles.
• These sheets are widely used in industries, factories, cinemas, auditoriums etc. 

Explanation: 

Concept:

Dorry abrasion test: 

• The test gives a measure of the resistance of aggregate to surface wear by abrasion. 
• Inadequate abrasion resistance of road-surfacing aggregates means an early loss of the texture depth required to maintain high-speed skidding resistance.
• Coefficient of hardness is calculated from Dorry abrasion test and it indicates resistance against external weathering of aggregates.

• \(Coefficient\,\,of\,\,Hardness= \,20\,-\,\frac{Loss\,\,in\,\,weight\,(gm)}{3}\)

• For good aggregate, it should not be less than 17.

• For medium quality aggregate, it is between 14 to 17.

Solution: given, loss in weight of aggregates = 21 gm, 

∴ \(Coefficient\,\,of\,\,Hardness= \,20\,-\,\frac{Loss\,\,in\,\,weight\,(gm)}{3} =\,20\,-\,\frac{21}{3} =\,\, 13\)

Explanation:

Terracotta:

• The most common uses for earthenware are roofing tiles and terracotta pots and dinnerware.
• Terracotta is used in the manufacturing of water and waste water pipes, roofing tiles, bricks, and surface embellishment in building construction.

Porcelain:

• Porcelain is a ceramic material made by heating substances, generally including materials such as kaolinite, in a kiln to temperatures between 1,200 and 1,400 °C. 
• Porcelain is used for tableware, decorative objects, laboratory equipment, and electrical insulators like switches, sockets, tubes, etc.

Explanation:

Laterite is claystone with a vesicular structure.

Vesicular texture

It is a rock texture characterized by a rock being pitted with many cavities (known as vesicles) at its surface and inside.

Among the given options, Laterite is the only clayey stone and it is formed from a wide variety of rocks under slow chemical weathering.

Because of this weathering, it has a vesicular appearance.

Hence among the given options, option (1) is the most appropriate answer

Laterite:

It is sandy claystone containing a high percentage of iron oxide

Its specific gravity varies from 2 to 2.2

Crushing strength = 1.8 to 32 kg/cm2

Explanation:

Splitting Tension Test on Rocks

• This is also called as Brazilian test. In this test, the specimen is split along the diametric plane by applying load.
• The specimen having the length to diameter ratio of unity when loaded on its side it splits along the diameter and parallel to the cylindrical axis. The horizontal stresses perpendicular to the loaded diameter are uniform and tensile. The tensile stress is given by

\({\sigma _t} = \frac{{2P}}{{\pi dt}}\)

where d = diameter, t = thickness or length of the cylinder, p = applied load.

Important Points

IS: 10082-1981 recommends that the diameter of the specimen should be at least 45 mm and the thickness of the disc shall be approximately equal to half the diameter.

The load should be applied at the rate of 0.2 KN/sec and the load should be measured at least to an accuracy of 1 %.

Concept:

Hardness:

• It is the ability of the material to resist scratch.
• It is measured by Mohs hardness test in which the mineral substances of known variation in hardness are used to scratch the rock.
• The following table shows the minerals and their mohs value -

Additional Information

The following listed test is used for aggregates -

Confusion Points

• Abrasion test is used for aggregates while Mohs scale test is used for stones/rocks.