STRUCTURAL MATERIALS

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• Q1: Write the main function of brick.
  Ans: The main function of a brick is to serve as a strong and durable building unit used for constructing walls, foundations, and other structural elements.
• Q2: Write the size of the brick in inches.
  Ans: The standard size of a brick in inches is 9 in × 4.5 in × 3 in.
• Q3: Write the size of the brick in centimeters.
  Ans: The standard size of a brick in centimeters is 23 cm × 11.5 cm × 7.5 cm.
• Q4: Write the size of the brick in millimeters.
  Ans: The standard size of a brick in millimeters is 230 mm × 115 mm × 75 mm.
• Q5: Name the ingredients used in making a brick.
  Ans: The ingredients used in making a brick are clay, sand, water, and sometimes lime and iron oxide.
• Q6: State the percentage of the ingredients used in making a brick.
  Ans: A typical brick contains:

  • ➔ 50—60% silica
  • ➔ 20—30% alumina
  • ➔ 5—10% lime
  • ➔ 5—10% iron oxide
  • ➔ Small amounts of magnesia
• Q7: Write the classification of bricks.
  Ans: Bricks are classified as:

  • ➔ First Class Bricks
  • ➔ Second Class Bricks
  • ➔ Third Class Bricks
  • ➔ Fourth Class (Overburnt) Bricks
• Q8: Define Frog in bricks.
  Ans: A frog is a rectangular depression on the top surface of a brick provided to form a proper key for mortar.
• Q9: Define Over burnt bricks.
  Ans: Over burnt bricks are bricks that are burnt too much in the kiln and become dark, distorted, and brittle.
• Q10: Define Under burnt bricks.
  Ans: Under burnt bricks are bricks that are not burnt sufficiently and remain soft, weak, and absorb more water.
• Q11: Write the formula of water absorption of bricks.
  Ans:
• Q12: Enlist the tests of standard brick.
  Ans: Tests for standard bricks include:

  • ➔ Water Absorption Test
  • ➔ Compressive Strength Test
  • ➔ Efflorescence Test
  • ➔ Hardness Test
  • ➔ Soundness Test
  • ➔ Shape and Size Test
• Q13: Write 4 classifications of first class bricks.
  Ans: First class bricks:

  • ➔ Have sharp edges and smooth surfaces.
  • ➔ Are well-burnt and uniform in color.
  • ➔ Have a water absorption of less than 15%.
  • ➔ Give a clear ringing sound when struck.
• Q14: Write 4 classifications of second class bricks.
  Ans: Second class bricks:

  • ➔ Have slightly irregular shapes and rough surfaces.
  • ➔ May contain small cracks.
  • ➔ Have a water absorption of about 20%.
  • ➔ Are moderately burnt and less strong than first class bricks.
• Q15: State the efflorescence test for bricks.
  Ans: The efflorescence test checks the presence of soluble salts by drying a brick after soaking it in water and observing white salt deposits on its surface.
• Q16: What is the hardness of stone?
  Ans: The hardness of a stone is its ability to resist scratching and abrasion.
• Q17: Name the methods of quarrying of stone.
  Ans: Methods of quarrying stone include:

  • ➔ Blasting
  • ➔ Channeling
  • ➔ Heating
  • ➔ Wedging
  • ➔ Digging
• Q18: Define Explosive Materials.
  Ans: Explosive materials are substances that produce a sudden and violent expansion of gases when ignited.
• Q19: Name some Explosive Materials.
  Ans: Some explosive materials are:

  • ➔ Dynamite
  • ➔ Gunpowder
  • ➔ TNT
  • ➔ Nitroglycerin
  • ➔ Blasting gelatine
• Q20: Write the types of dressing of stone.
  Ans: Types of stone dressing include:

  • ➔ Hammer Dressing
  • ➔ Chisel Dressing
  • ➔ Fine Dressing
  • ➔ Rough Tooling
  • ➔ Polishing
• Q21: State the requirement of good building stone.
  Ans: A good building stone must be:

  • ➔ Strong
  • ➔ Durable
  • ➔ Hard
  • ➔ Easily workable
  • ➔ Resistant to weathering
• Q22: Write the characteristics of good building stone.
  Ans: A good building stone has:

  • ➔ High compressive strength
  • ➔ Low water absorption
  • ➔ Good appearance
  • ➔ Resistance to fire
  • ➔ Resistance to decay
• Q23: Enlist different methods used in dressing of stone.
  Ans: Methods of dressing stone include:

  • ➔ Hammer dressing
  • ➔ Chisel dressing
  • ➔ Fine dressing
  • ➔ Rough tooling
  • ➔ Polishing
• Q24: What type of stone is recommended for the construction of an external wall?
  Ans: A hard, durable, and weather-resistant stone like granite or sandstone is recommended for external walls.
• Q25: What is pitch in timber?
  Ans: Pitch in timber is the resin or sticky substance found in the wood that protects it from insects and decay.
• Q26: What is pith in timber?
  Ans: Pith in timber is the soft, central core of the tree trunk that represents the earliest growth of the tree.
• Q27: Define Sap wood.
  Ans: Sapwood is the outer, younger part of the tree trunk that is lighter in color and helps in the transport of sap.
• Q28: What are Annual Rings?
  Ans: Annual rings are the visible circular layers in a tree trunk that show the growth of the tree during each year.
• Q29: What is Bark wood?
  Ans: Bark wood is the outer protective layer of a tree that covers and shields the inner wood.
• Q30: What are Medullary Rays in timber?
  Ans: Medullary rays are narrow radial bands that carry nutrients from the inner part of the tree to the outer part.
• Q31: Define Heart wood.
  Ans: Heartwood is the inner, older, darker, and harder part of a tree that provides strength to the timber.
• Q32: Define Soft wood.
  Ans: Softwood is wood obtained from coniferous trees, which is light, less dense, and easy to work with.
• Q33: Define Hard wood.
  Ans: Hardwood is wood obtained from broad-leaved trees, which is dense, strong, and more durable.
• Q34: Define seasoning of timber.
  Ans: Seasoning of timber is the process of removing moisture from wood to make it stronger, lighter, and more durable.
• Q35: Name two methods of seasoning of timber.
  Ans: Two methods of seasoning timber are:

  • ➔ Natural seasoning (air seasoning)
  • ➔ Artificial seasoning (kiln seasoning)
• Q36: What is decay in timber?
  Ans: Decay in timber is the decomposition of wood fibers caused by fungi, moisture, or insects.
• Q37: Write the factors that lead to the decay of wood.
  Ans: Factors that lead to decay include:

  • ➔ Moisture
  • ➔ Fungal attack
  • ➔ Insect attack
  • ➔ Lack of ventilation
  • ➔ Poor seasoning
• Q38: What is Artificial seasoning?
  Ans: Artificial seasoning is the controlled drying of wood using machines or kilns to remove moisture quickly.
• Q39: What are the types of artificial seasoning?
  Ans: Types of artificial seasoning include:

  • ➔ Kiln seasoning
  • ➔ Chemical seasoning
  • ➔ Electrical seasoning
  • ➔ Hot-air seasoning
• Q40: What are the defects during the growth of trees?
  Ans: Defects during growth include:

  • ➔ Knots
  • ➔ Shakes
  • ➔ Twisted fiber
  • ➔ Rind galls
  • ➔ Uneven rings
• Q41: What are the characteristics of good timber?
  Ans: Good timber is:

  • ➔ Strong
  • ➔ Durable
  • ➔ Elastic
  • ➔ Free from defects
  • ➔ Well-seasoned
  • ➔ Resistant to insects and moisture
• Q42: Could soft wood be stronger than hard wood?
  Ans: Yes, some softwoods can be stronger than certain hardwoods because strength depends on the wood’s density and structure, not only on its classification.
• Q43: Why should timber be seasoned before constructional use?
  Ans: Timber should be seasoned before use because seasoning removes excess moisture, increases strength, reduces weight, and prevents decay and shrinkage.
• Q44: Define Water seasoning.
  Ans: Water seasoning is a method of soaking timber in flowing water to remove sap and moisture from the wood.
• Q45: Define Endogenous trees.
  Ans: Endogenous trees are trees that grow inward by adding layers on the inside; examples include bamboo and palm.
• Q46: Define Exogenous trees.
  Ans: Exogenous trees are trees that grow outward by adding annual rings; examples include teak, oak, and pine.
• Q47: Define Wet concrete.
  Ans: Wet concrete is freshly mixed concrete that is soft, plastic, and workable before it hardens.
• Q48: How does concrete mix gain strength?
  Ans: Concrete gains strength through the chemical reaction between cement and water, known as hydration.
• Q49: Write down the composition of concrete.
  Ans: Concrete is made of cement, sand, aggregate, and water.
• Q50: Define Batching in concrete.
  Ans: Batching in concrete means measuring the correct quantity of each material before mixing.
• Q51: Write the role of vibrator in compaction.
  Ans: A vibrator removes air bubbles, makes the concrete dense, and increases its strength and durability.
• Q52: Name the methods used for transporting fresh concrete.
  Ans: Fresh concrete can be transported by:

  • ➔ Wheelbarrows
  • ➔ Transit mixers
  • ➔ Pumps
  • ➔ Buckets
  • ➔ Trucks
• Q53: Name the methods used for compacting concrete.
  Ans: Concrete is compacted using:

  • ➔ Hand compaction
  • ➔ Needle vibrators
  • ➔ Surface vibrators
  • ➔ Form vibrators
• Q54: Explain methods of concrete finishing.
  Ans: Concrete finishing includes:

  • ➔ Screeding to level the surface
  • ➔ Floating to smooth it
  • ➔ Trowelling to give a hard, even finish
• Q55: Define curing of concrete.
  Ans: Curing is the process of keeping concrete moist so that it hardens properly and gains full strength.
• Q56: Name the methods used for curing of concrete.
  Ans: Methods of curing include:

  • ➔ Ponding, spraying water
  • ➔ Covering with wet burlap/jute bags
  • ➔ Steam curing
  • ➔ Using curing compounds
• Q57: Write the properties of high carbon steel.
  Ans: High carbon steel is very hard, strong, wear-resistant, and difficult to weld and cut.
• Q58: Name the common construction steel used in construction works.
  Ans: Common construction steels include:

  • ➔ Mild steel
  • ➔ High-strength deformed steel bars (TMT bars)
  • ➔ Structural steel sections
• Q59: Define steel.
  Ans: Steel is an alloy made mainly of iron and carbon, with small amounts of other elements.
• Q60: Write the carbon content of Mild steel.
  Ans: Mild steel contains 0.05% to 0.25% carbon.
• Q61: Define Mild steel.
  Ans: Mild steel is a low-carbon steel that is ductile, easily weldable, and commonly used in construction.
• Q62: Define Medium Carbon steel.
  Ans: Medium carbon steel is steel with moderate carbon content, making it stronger and harder than mild steel but less ductile.
• Q63: Write the carbon content of High Carbon steel.
  Ans: High carbon steel contains 0.6% to 1.5% carbon.
• Q64: Write the carbon content of Medium Carbon steel.
  Ans: Medium carbon steel contains 0.25% to 0.60% carbon.
• Q65: Define Plain steel.
  Ans: Plain steel is steel that has a smooth surface and does not contain ribs or deformations.
• Q66: Define Deformed steel.
  Ans: Deformed steel is steel that has ribs or projections on its surface to increase the bond with concrete.
• Q67: Define Cold twisted steel bars.
  Ans: Cold twisted steel bars are steel bars that are twisted after cooling to increase their strength and bond with concrete.
• Q68: Why do we need joints in concrete construction?
  Ans: Joints are needed to control cracking, allow expansion and contraction, and make construction easier.
• Q69: Define Forsterite bricks.
  Ans: Forsterite bricks are refractory bricks made from magnesium silicate, used in high-temperature furnaces.
• Q70: Define Kiln seasoning of wood.
  Ans: Kiln seasoning is the process of drying timber in a closed chamber using controlled heat, air, and humidity.
• Q71: Define Elasticity.
  Ans: Elasticity is the ability of a material to return to its original shape after the load is removed.
• Q72: Define Plasticity.
  Ans: Plasticity is the ability of a material to be permanently deformed without breaking.
• Q73: Define Hardness.
  Ans: Hardness is a property of material that tells how hard or soft a material is.
• Q74: Define Creep.
  Ans: Creep is the slow, permanent deformation of a material under a constant load over time.
• Q75: Define Ductility.
  Ans: Ductility is the ability of a material to be stretched into a wire without breaking.
• Q76: Define Malleability.
  Ans: Malleability is the ability of a material to be hammered or rolled into thin sheets.
• Q77: Define Toughness of metal.
  Ans: Toughness is the ability of a metal to absorb energy and resist fracture.
• Q78: Name some types of sand.
  Ans: Types of sand include:

  • ➔ River sand
  • ➔ Pit sand
  • ➔ Sea sand
  • ➔ Manufactured sand (M-sand)
• Q79: Define Aggregate.
  Ans: Aggregate is a granular material such as sand, gravel, or crushed stone used in concrete.
• Q80: Define Fine Aggregate.
  Ans: Fine aggregate is sand or particles smaller than 4.75 mm used to fill gaps in concrete.
• Q81: Define Coarse Aggregate.
  Ans: Coarse aggregate is gravel or crushed stone with particles larger than 4.75 mm.
• Q82: Define Slag Aggregate.
  Ans: Slag aggregate is a by-product of metal industries used as an alternative to natural aggregates.
• Q83: Define Admixtures.
  Ans: Admixtures are materials added to concrete to improve its properties or performance.
• Q84: Name 4 Admixtures.
  Ans: Four admixtures are:

  • ➔ Plasticizers
  • ➔ Superplasticizers
  • ➔ Accelerators
  • ➔ Retarders
• Q85: Write 4 uses of Admixtures.
  Ans: Admixtures are used to:

  • ➔ Improve workability
  • ➔ Increase or decrease setting time
  • ➔ Increase strength and durability
  • ➔ Reduce water content in the mix
• Q86: Define Rubble Masonry.
  Ans: Rubble masonry is masonry made using rough, irregular, and undressed stones.
• Q87: Name the types of Rubble Masonry.
  Ans: Types of rubble masonry include:

  • ➔ Random rubble masonry
  • ➔ Coursed rubble masonry
• Q88: Define Ashlar Masonry.
  Ans: Ashlar masonry is masonry made using finely dressed stones laid in regular courses.
• Q89: Name the types of Ashlar Masonry.
  Ans: Types of ashlar masonry include:

  • ➔ Ashlar fine
  • ➔ Ashlar rough
  • ➔ Ashlar block-in-course
  • ➔ Ashlar chamfered
• Q90: State some Man-made stones.
  Ans: Man-made stones include:

  • ➔ Cement concrete blocks
  • ➔ Artificial stones
  • ➔ Terrazzo tiles
  • ➔ Hollow blocks
• Q91: Define Mortar.
  Ans: Mortar is a mixture of cement or lime, sand, and water used to bind building materials together.
• Q92: State the types of mortar.
  Ans: Types of mortar include:

  • ➔ Cement mortar
  • ➔ Lime mortar
  • ➔ Mud mortar
  • ➔ Composite mortar
• Q93: Write 4 advantages of brick masonry.
  Ans: Advantages of brick masonry:

  • ➔ Bricks are durable and fire-resistant
  • ➔ Brick masonry is economical
  • ➔ Bricks provide good thermal insulation
  • ➔ Brick masonry is easy to construct and maintain
• Q94: Define Puca brick.
  Ans: Puca bricks are well-burnt, strong, and durable bricks used in permanent construction.
• Q95: Define Kutcha brick.
  Ans: Kutcha bricks are sun-dried, weak, and temporary bricks used in low-cost structures.
• Q96: Define Quoins.
  Ans: Quoins are the corner stones or bricks used at the external corners of walls.
• Q97: Define Quoin brick.
  Ans: A quoin brick is a specially prepared brick used at the corners to give strength and a neat finish.
• Q98: Define Queen closer.
  Ans: A queen closer is a brick cut lengthwise into two equal parts to maintain proper bonding.
• Q99: Define King closer.
  Ans: A king closer is a brick cut diagonally from the corner to nearly half its width.
• Q100: Name the types of brick bond.
  Ans: Types of brick bond include:

  • ➔ English bond
  • ➔ Flemish bond
  • ➔ Stretcher bond
  • ➔ Header bond
  • ➔ Rat-trap bond
• Q101: Define English bond.
  Ans: English bond is a brick bond formed by alternate courses of headers and stretchers.
• Q102: Define Flemish bond.
  Ans: Flemish bond is a brick bond in which each course consists of alternating headers and stretchers.
• Q103: Define Stretcher bond.
  Ans: Stretcher bond is a brick bond in which all bricks are laid as stretchers along the wall length.
• Q104: Define Header bond.
  Ans: Header bond is a brick bond in which all bricks are laid with their short face (header) on the wall face.
• Q105: Write the soundness test of brick.
  Ans: In the soundness test, two bricks are struck together; a good brick produces a clear ringing sound.
• Q106: Define Weathering.
  Ans: Weathering is the process of breaking down materials due to natural factors like wind, rain, temperature changes, and sunlight.