Construction Materials and Engineering Diploma (Polytechnics)

1. Construction Materials
and Engineering
Module - II

3. Paints
Applied on surfaces of timber, metals & plastered surfaces
On drying paint forms a thin film on the painted surface
A liquid Surface coating material

4. Functions of paints
For pleasing appearance
Check/stop penetration of water
Check the formation of bacteria and fungus
Check corrosion of structures
Act as a protective coating against climatic changes
Provides smooth surface for easy cleaning.

5. Properties of an Ideal Paint
It should be possible to apply easily and freely.
It should form hard and durable surface.
It should not be harmful to the health of workers
It should not be easily affected by atmosphere.
It should possess attractive and pleasing appearance.
It should dry in reasonable time.
It should not crack and should be cheap
It should possess good spreading power.
Ordinary paint hardens by oxidation

6. Ingredients in paints
Base
Vehicle (Carrier)
Drier
Pigment
Solvent

7. Base1
Solid fine substance which forms bulk of paint
Eg: White lead
Determines character and durability of paint
Red Lead
Zinc White (Oxide of Zinc)
Oxide of Iron
Titanium white
Principal constituent forming the body of paint
Lithophone

8. Vehicle (Carrier/binder)2
Liquid substances holding ingredients of paint
Eg: Linseed oil
Defines the spreading power of paint
Tung oil
Poppy oil
Nut oil

9. Drier3
To accelerate process of drying and hardening
Eg: Litharge
While hardening driers absorb oxygen from
atmosphere and transfers it to linseed oil.
Red lead

10. Pigments4
Ingredient which provide colours to paint
Eg: Black  Add Graphite
Pigments available in form of fine powders.
Green  Copper Sulphate
Red  Red lead
Available in different colours and qualities.

11. Solvent (Thinner)5
Makes the paint thin and helps for easy application
Eg: Turpentine
Not used in finishing coats (damage to firmness)
Naphtha
Have high penetration power
Benzene

12. Types of Paints
1. Aluminium Paint
2. Anti-corrosive Paint
3. Asbestos paint
4. Bituminous paint
5. Cellulose paint
6. Cement paint
7. Colloidal paint
8. Emulsion paint
9. Enamel paint
10. Graphite paint
11. Inodorous paint
12. Luminous paint
13. Oil paint
14. Plastic paint
15. Silicate paint
16. Synthetic rubber paint

13. Aluminium paint1
Contain finely ground aluminium in spirit/ oil varnish
It is visible in darkness
High corrosion resistance – commonly used for metals
Oil/spirit evaporates and thin film layer forms on surface
High spreading power – 200 m2/Litre
Uses: for painting gas tanks,
radiators, oil storage tanks

14. Anti-corrosive paint2
Consist of oil and strong drier
It is Cheap and black in colour
Durable – last for a long duration
Resist corrosion well

15. Asbestos paint3
Applied to surfaces exposed to acidic gases and steams
Bituminous paint4
Manufactured by dissolving asphalt or
vegetable bitumen in oil or petroleum
It is black in colour
Used for painting under water iron works.

16. Cellulose paint5
Prepared from nitro cotton, celluloid sheets and
photographic films
Hardens by evaporation (not by oxidation) of thinner
Hardens quickly
Can withstand extreme cold and hot
Can be washed & cleaned easily
Widely used to aint motor vehicles

17. Cement paint6
White cement + pigment + accelerator + additives
Available in dry powder form
Mixed with water immediately before its application
Water proof and durable
Applied in two coats
Requires less skill

18. Colloidal paint7
Requires more time to settle
High penetration power
No inert materials is mixed in this paint
Used for interior and exterior walls

19. Emulsion paint8
It contains binding materials such as polyvinyl acetate,
synthetic resins, etc
Easy to apply
Dries quickly (1.5 – 2 hours)
High alkali resistance

20. Enamel paint9
White lead + Oil + Petroleum spirit + resins
Available in different colours
Dries slowly and form hard and durable surface
Not affected by acids, alkalies, gases,
hot and cold water, steam, etc
For good appearance,
titanium white is also added

21. Graphite paint10
Black colour
Applied on iron surfaces
Used in mines and underground railways
Inodorous paint11
No turpentine is used in this paint
White lead (or Zinc white) + Spirit
Not durable, but dries quickly.

22. Luminous paint12
Contains calcium sulphide and varnish
Shines after the light is off
Oil paint13
Ordinary paint
Applied in 3 coats
Cheap and easy to apply Primer
undercoat
finishing coat

23. Plastic paint14
Contains necessary variety of plastics
Good appearance- showrooms, auditoriums, etc
Silicate paint15
Silica + resinous materials
High temperature resistance
Not affected by alkalies

24. Synthetic rubber paint16
Prepared from resins
Good resistance to water
Easy to apply on surfaces
Good chemical resistance

25. Preparation of paint
Paste 1 = Base + Vehicle = Muller
Muller is prepared by grinding base and vehicle
to the consistency of a paste in a stone pestle
1
Paste 2 = Pigments + Linseed oil
Mix the pigments and linseed oil separately
using wooden puddle to form second paste
2
Paste 3 = Drier + Linseed oil
Mix drier and linseed oil separately to
form third paste
3

26. Preparation of paint
Mix three pastes
The mixture is stirred continuously till a
consistency cream is obtained
4
Sieve the mixture
This cream is passed through fine sieves and
paint is now ready to use
5
Control workability
To increase workability/consistency, oil or
thinners are added
6

27. Stage - 1
Stage - 2
Stage - 3
Consistency cream
Paint
Base + Vehicle = Muller
Linseed oil, pigments
Mixing & Grinding
Driers, chemicals, linseed oil
Dilution
Sieve
Stir continuously

28. Application of paint - factors
Make the surface ready for application of paint
Surface to be painted should not be oily
Cracks should be filled with putty & then with sand paper
Apply one coat of primer
Painting work should be carried out in dry weather
The under coats and first coats must be allowed to dry
before final coat is applied

29. Plastics
Plastic is an organic substance
It consist of natural or synthetic binders/resins
Capable to flow when heated (Plasticity)
Can be moulded into required size and shape

30. Classification of Plastics
Behaviour
w.r.t heating
1. Thermo-plastics
2. Thermo-setting
plastics
Structure
1. Homogeneous
2. Hetrogeneous
Phy & mech
properties
1. Rigid plastics
2. Semi-rigid plastics
3. Soft plastics
4. Elastomers

31. Behaviour w.r.t heating
Softens on heating
Hardens on cooling
Reversible - reusable
Formed by Addition
polymerization
Have long chain
molecular structure
Eg:- Nylon 6
Thermoplastics Thermo-setting plastics
Cannot be reused
Chemical reaction in this process
cannot be reversed
Formed by condensation
polymerization
Eg:- Electrical equipments, switches
(Bakelite)

32. Characteristics and properties
1
Good appearance
Available as transparent, opaque, attractive,
stable and translucent colours
2
Good chemical resistance
Offers great resistance to moisture, chemicals
and solvents.
3 Sufficient dimensional stability
4 Sufficient ductility
Members may fail without warning

33. Good durability and weathering resisitance
Good electrical insulation
Low weight and good finishing
Good fire resistance
Can be easily fixed in position
Easy maintenance, cheap and can be recycled
Characteristics and properties

34. Uses of plastics
PVC Pipes - fixtures
Utensils, bottles, etc
Bath and sink units
Corrugated and plain sheets
Floor and wall tiles
Overhead water tanks
Safety glass
Electrical conduits
Wire insulations
Pen coverings
Lighting fixtures
Concrete curing sheets

35. Advantages of plastics
Offers great resistance to moisture, chemicals and solvents.
Good durability
Plastic possess good insulating properties
Can be easily fixed in position
Weight of material is low compared to others and cheap
Have high tensile strength
Require no maintenance. Occasional cleaning only required
Can be mould into any shape without cracks
over other building materials

36. Limitations of using plastics on environment
Harmful to the nature - pollution
Causes environmental degradation
Burning of plastics causes health hazards – toxic fumes
Have low melting point  Fire hazard
Plastics usually have short useful life compared to metals
Non renewable - Cost of recycling is high.
Threat to animal life  suffocation

37. PVC – Polyvinyl Chloride
Synthetic plastic polymer
Formed by polymerization of vinyl chloride monomer
Applications
1. Pipes and ropes
2. Electric cables
3. Construction works
4. Flat sheets
5. Clothing
6. Flooring

38. Characteristics and properties
Rust proof, thermal proof and water proof
Provide alternative to wood in many cases
Resist dust penetration
Unaffected by coastal saline air and dry heat
Available in different colour and shade
They don't fade, corrode, flake or warp
Require no maintenance. Occasional cleaning only required
Better thermal insulator

39. Rubber
Polymers capable of undergoing large deformations
under load and returning to their original shape
Uses
1. Conveyor belts
2. Linings of tanks
3. Automobile tyres
4. Gasket of doors and windows
5. Ropes and wires
6. Cycle tyres and tubes
7. Footwears, etc

40. Types of rubber
Natural rubber Synthetic rubber
Obtained from latex Also called as artificial rubber
Poly Butadiene Rubber (PBR)
Poly Isoprene Rubber (PIR)
Synthetic Butadiene Rubber (SBR)

41. Characteristics and properties
It can adsorb shocks due to impact
It can contain liquids and gases
It extends in length as result of applied force
It is bad conductor of heat
Good flexibility
Resists abrasion
Great resistance to acid and petroleum products
Can undergo great deformation without structural damage

42. Good conductor of heat and electricity
Highly resistant to corrosion
Have good scrap value
Light weight and takes more load
Specific gravity = 2.7
Possess great toughness and tensile strength
Ore: Bauxite (Al2O3.2H2O)
Aluminium
It readily dissolves in Hydrochloric acid

43. Hand rails and balusters
Paneling and false ceiling works
Building facades
Furnitures
Aluminium fabrication works
Doors and windows – airtight/ AC buildings
Aluminium used for building construction
Facades
Body parts of equipments

44. Glass
Super cooled solution of various metallic silicates
having infinite viscosity.
Melting point = 800 – 950oC

45. Available in beautiful colours
Hard and extremely Brittle
Properties of glass
Amorphous – no definite crystalline structure
Transparent or translucent
Can absorb, refract, reflect and transmit light
Has no sharp melting point - range

46. It is an excellent electrical insulator
Not easily attacked by chemicals
Properties of glass
Possible to weld glass pieces by fusion
It is affected by alkalies
Not usually affected by water or air

47. Vehicle glasses and goggles
Medicine bottles
Furnitures, lampshades, bathroom fittings
Photographic developments
Prisms, lenses, mobile screens
Laboratory equipments
Furnitures, lampshades, bathroom fittings
Uses of glass

48. Types of glass
Soda Lime glass1
Potash Lime glass2
Potash Lead glass3
Common glass4

49. Sodium silicate + Calcium silicate
Uses:
Manufacture of glass tubes
Window glass
Plate glass
Laboratory equipments
Also known as soda glass
1. Soda Lime glass
Fuses easily

50. Potassium silicate + Calcium silicate
Uses:
Combustion tubes
Also known as Bohemian or hard glass
2. Potash Lime glass
Difficult to fuse – high temperature needed
Glassware for heating operations - bulbs

51. Potassium silicate + Lead silicate
Uses:
Manufacture of artificial gems
Electric bulbs
Lenses, prisms
Also known as Flint glass
3. Potash Lead glass
Fuses easily, lustre, and great refractive power

52. Sodium silicate + Calcium silicate + iron silicate
Uses:
Medicine bottles
Also known as Bottle glass
4. Common glass
Fuses with difficulty

53. Types of glass used for glazing
Floating glass1
Laminated glass2
UV resistant glass3
Reinforced glass4
Reflective glass5

54. Monolithic and highly transparent
Most widely used type of glass
1. Floating glass
Produced by flowing molten glass over a bath
of molten tin and slowly cooling
Uses:
Windows, doors, etc

55. Made by sandwiching two glass plates with a
high resistance plastic skin in between.
2. Laminated glass
Uses:
Facades, balconies, guard rails,
partitions, showcases, floorings

56. Resist UV rays entering rooms
3. UV Resistant glass
Uses:
Laboratory and research spaces
Reinforced with steel mesh to make it stronger
4. Reinforced glass
Uses:
Partition walls, external walls, ocean walls

57. Ordinary float glass with a metallic coating
5. Reflective glass
Uses:
Façade glazings
Reflects and creates a mirror effect
For providing aesthetic appearance

58. Special varieties of glass
Bullet proof glass1
Fiber glass2
Float glass3
Foam glass4
Glass blocks5
Heat excluding glass6
Obscured glass7
Perforated glass8
Safety glass9
Shielding glass
Soluble glass
Structural glass
UV ray glass
Wired glass
10
11
12
13
14
(Glass used for Structural applications)

59. Miscellaneous materials
Abrasives1
Adhesives
Asbestos
Asphalt
Bitumen
Cork
Plaster of Paris2
3
4
5
6
7
Acoustic materials8
Fiber glass
Thermocole
9
10

60. Hard materials used to cut/shape/polish
other materials
1. Abrasives
Natural abrasives and synthetic abrasives
• Diamond
• Garnet
• Emery
• Sandstone
• corundum
• Carbide of Aluminium
• boric acid
• silicon
Forms – Sand paper, stones, grinding paste with oil

61. To join or create bond b/w two or more
materials so as to form a single unit.
2. Adhesives (Glues)
Examples of adhesives
1.Albumin glue
2.Animal protein glues
3.Glues from natural resins
4.Glues from synthetic resins
5.Starch glues
6.Vegetable glues

62. Naturally occurring fibrous mineral substance
3. Asbestos
Excellent insulator of heat and electricity
Composed of hydrous silicates of calcium and
magnesium with small amount of iron oxide
and alumina.
Can be cut into pieces, holes can drilled
Good adsorption capacity – asbestos cement
Uses: Roofing, pipes, brake linings, gaskets

63. Mechanical mixture of alumina, lime, silica and
asphaltic bitumen
4. Asphalt
Remains in solid state at low temperature
Black or brownish-black in colour
Uses: Water proofing floors and roofs, DPC,
Swimming pools, roads and pavements
Types: Natural and Residual (Artificial)
Becomes liquid at 50oC to 100oC
Water/fire/sound/acid proof

64. Binding material present in asphalt
5. Bitumen (Mineral tar)
Insoluble in water, but completely soluble in
carbon bisulphide, chloroform, naphta, etc.
It is chemically a hydrocarbon
Uses: Water proofing floors and roofs, DPC,
Swimming pools, roads and pavements
Obtained by fractional distillation of crude petroleum
Black or brown in colour

65. Obtained from bark of oak trees
6. Cork
Uses:
• For preparing cork sheets & boards
• Bottle stoppers
• Packing gaskets
• Cork carpets as floor coverings
(Churches, theaters, etc – noiseless covering)

66. Produced by heating gypsum to 150oC
7. Plaster of Paris
White colour and in powder form
CaSO4.2H2O → CaSO4.
𝟏
𝟐
H2O + 1.5H2O
Can be easily shaped when wet
Uses:
• For aesthetic appearene
• Wall panels, casting works
• Ceiling works, acoustics

67. Sound absorbent materials used to proof sound
8. Acoustic materials
Absorbs sound and prevents echo in the room
Acoustics of rooms, studios, theatre halls
Eg:- Acoustic plaster, perforated plywood, mats
Uses:
• Acoustics of rooms
• Sound systems in studios
• Theatre halls
• Commercial centers

68. Composed of minute glass rods
9. Fibre glass
Soft and flexible in nature
Water/sound/fire/vermin/acids proof
Uses:
• Thermal insulations
• Sheets
• Fibre Glass Reinforced Plastics (FGRP)

69. A type of plastic - Polystyrene
10. Thermocole
Light weight and white colour
Cushioning property
Uses:
• Sound insulation in auditorium and theaters
• Cushion for various equipments
• Craftworks and model preparations
Can be moulded to desired shape easily
Used for acoustics in ceiling works

70. Wood products
Major wood products are
1. Veneer
2. Plywood
3. Particleboard
4. Fibreboard
5. Hardboard

71. 1. Veneer
Thin sheets of wood of superior quality
Thickness = 0.4 mm to 6 mm
Obtained by rotating a log of wood against a
shark knife of rotary cutter
Dried in kilns to remove moisture

72. Process of preparing a sheet of veneer is
known as veneering.
Veneers are used to produce plywood's,
batten boards, and laminboards.
Glued on the surface of inferior wood to
create an impression that whole piece is
made of expensive timber

73. 2. Plywoods
Ply means thin layer
Veneers placed in both longitudinal and transverse
directions  more strength
Suitable adhesives are used to held in position
Available in different commercial sizes

74. Used for:
1. Ceilings
2. Doors
3. Furniture
4. Partitions
5. Paneling walls
6. Formworks of concrete

75. 3. Particle board
Formed by breaking down real wood residuals
into wood fibers and glued back together with
special resin by applying high temperature and
pressure
Light in weight
Used for making
readymade furniture

76. 4. Fiberboard (Pressed/reconstructed wood)
Rigid boards
Thickness = 3 mm to 12 mm
Not able to take loads

77. Used for:
1. Interior decorations
2. Doors
3. Partitions
4. Panel works

78. 5. Hardboard
Wood pulp is pressed under
high temperature and water is removed.
Sheets are smooth on one side and textured on
other side
Thickness = 3 – 9 mm