Construction Materials and Engineering Diploma (Polytechnics)

1. Construction Materials
and Engineering
Shamjith Km
shamjithkeyem@gmail.com
Department of Civil Engineering
Government Polytechnic College Manjeri

2. Stones Clay Tiles Lime
Cement Puzzolana Aggregates Mortar
Concrete Timber Metals Non-Metals
Module 1:
Structural Building Materials

3. Geological Physical Chemical
Stones1
1. Igneous
2. Sedimentary
3. Metamorphic
1. Stratified
2. Unstratified
3. Foliated
1. Siliceous
2. Argillaceous
3. Calcareous
Classification of rocks
Naturally available building material
Obtained from rocks

4. Igneous rocks1
Formed by cooling of magma
Molten/pasty
rocky material
High
temperature

5. Volcanic Hypabyssal Plutonic
Igneous rocks
Earth’s surface Shallow depth Considerable depth
Rapid cooling Fast cooling Slow cooling
Extremely fine
glassy structure
Fine grained
crystalline structure
Coarse grained
crystalline structure
Eg:- Basalt, trap Eg:- Dolerite Eg:- Granite

6. Sedimentary rocks2
Weathering  Transportation  Sedimentation
Sedimentation through agencies like
water, wind or glaciers

7. Examples
Chalk
Kankar
Limestone
Sandstone
Gravel
Gypsum

8. Residual
Types of Deposits
Sedimentary OrganicChemical
fine weathered particles get washed away
weathered coarser particles
remains in the origin site and sets in layers
Parent rock

9. Residual
Types of Deposits
Sedimentary
insoluble fine
weathered aggParent rock
agents/rain
deposited as
layers
OrganicChemical

10. Residual
Types of Deposits
Sedimentary
Deposited by physio-chemical process.
Eg:- Evaporation, precipitation
Tsunami, acid rain, etc.
OrganicChemical

11. Residual
Types of Deposits
Sedimentary
Deposited through agency of organisms.
OrganicChemical
Eg: Bacteria
Vegetable wastes, human Soil (Organic deposits)

12. Metamorphic rocks3
Formed by the change in
character of pre-existing rocks.
Agents:
Heat, Pressure, Chemically acting fluids

13. Igneous
Sedimentary
agents
loss eqm
Change-in
character
re-establish
equilibrium
Metamorphic
rocks

14. Igneous
Sedimentary
agents
loss eqm
Change-in
character
re-establish
equilibrium
Metamorphic
rocks
Examples:-
Granite  Gneiss
Basalt  Laterite/Schist
Limestone  Marble
Mudstone  Slate
Siliceous sand  Quartzite

15. Igneous
Sedimentary
agents
loss eqm
Change-in
character
re-establish
equilibrium
Metamorphic
rocks
Examples:-
Granite  Gneiss
Basalt  Laterite/Schist
Limestone  Marble
Mudstone  Slate
Siliceous sand  Quartzite
(High compressive strength)
(Specific gravity = 2.72)

16. Thermal
Types of Metamorphism
Cataclastic
Heat
PlutonicDynamo-thermal
Pressure Heat + Stress Uni. Pressure
+ Heat

17. Stratified Unstratified Foliated
Physical classification
Can easily split along
planes of cleavage
Eg:-
Sedimentary rocks
Distinct layers
Compact crystalline
Can’t split in desired
layers.
No distinct layers
Eg:-
Igneous rocks
Layered structure
Split easily along
planes of foliation.
Eg:-
Metamorphic rocks
Sedi.rocks MetaMor

18. Siliceous Argillaceous Calcareous
Chemical classification
Eg:-
Granite, Quartzite
High silica content High clay/Alumina
content
Eg:-
Slate, Laterite
Clay minerals
- Kaolin, Illite
- Montmorillonite
High CaCO3 content
Eg:-
Limestone, Marble
High fire resistance

19. Classification of rocks
Geological Physical Chemical
1) Igneous rocks
2) Sedimentary rocks
3) Metamorphic rocks
1) Stratified rocks
2) Unstratified rocks
3) Foliated rocks
1) Siliceous rock
2) Argillaceous rocks
3) Calcareous rocks
- Formed by cooling of magma
- Eg:- Granite, Dolerite, Basalt
- Due to weathering action of
water, wind and frost
- Eg:- Gravel, Gypsum, limestone
- Formed by change in character
of existing rocks when subjected
to heat and pressure
- Eg:- Quartzite, slate, marble
- Have planes of cleavage
- Can split into layers
- Eg:- Sedimentary rocks
- No distinct layers
- Eg:- Igneous rocks
- Rocks having a tendency to split up
in a definite direction only
- Eg:- Metamorphic rocks
- High silica content
- Eg:- Granite, Quartzite
- High clay content
- Eg:- Slate, Laterite
- High CaCO3 content
- Eg:- Marble, Lime stone
- Durability depends on
surrounding materials
Plutonic, Hypabyssal, Volcanic

20. Note:
Shingle – decomposed laterite
Diamond – Kimberlite (Igneous rock) – Hardest rock
Talc – Softest rock
Gneiss is obtained from sedimentary metamorphic rocks

21. Crushing Strength
Characteristics of a good building stone
1 > 100 N/mm2
Appearance2
Durability3
Fracture4
Hardness5
Uniform colour
Long lasting in changing weather conditions
Sharp, even and clear fracture
 > 17 = Hard = used in roads
 14-17 = Medium hardness
 < 14 = Poor Hardness
Percentage wear6 ≤ 3 %

22. Characteristics of a good building stone
Good Fire resistance7
Specific gravity8
Texture9
> 2.7
 Have compact fine crystalline structure
 Should be free from cavities, cracks or patches
Seasoning11 Upto 6-12 months
Toughness index12
Water absorption10 % absorption by weigth after 24 hours
should not exceed 0.60
 < 13 = not tough
 13-19 = Moderate
 >19 = High- Impact test

23. Varieties of stones
Granite
• Igneous rock – Plutonic
• Composed of quartz + feldspar + Silica
• Available in colors: Grey, Green, Brown, Pink, Red
• Hard, durable, high resistance to weathering
• Specific gravity = 2.7
• Compressive strength = 700 – 1300 N/mm2.
• Uses: Ornamental works, flooring, walls etc

24. Varieties of stones
Trap rock
• Igneous rock - Volcanic
• Dark colour
• Specific gravity = 2.8 – 3.0
Eg:- Basalt
Uses : As crushed rocks,
railway ballast

25. Varieties of stones
Basalt
• Igneous rock - Volcanic
• Compact, Hard
• Colour: Red, Yellow, Grey, Blue
• Specific gravity = 3
• Compressive strength = 1530 – 1890 N/mm2.
• Uses: aggregates for concrete, ornamental works

26. Varieties of stones
Sand Stone
• Sedimentary rock
• Fine/coarse grained
• Specific gravity = 2.65 – 2.95
• Compressive strength = 650 N/mm2.
• Used for Ashlar works

27. Varieties of stones
Laterite
• Sedimentary rock
• Hard and durable
• Rich in Fe and Al
• Colour : Rusty red
(high iron oxide content)
• Uses: Building blocks

28. Load bearing capacities of stones

29. Quarrying of stones
Process of extracting or taking out stones
from natural rock beds.
Quarry – Exposed surface of a natural rock
Quarry Site – Site from where stones are taken

30. • Availability – tools, materials and labour
Selection of quarry site
• Quality of building stone should not vary with depth
• Distance should be min from transportation facilities
• Space for disposal of refuse and quarry wastes - near
• Geological information about the site
• Availability of water
• No health hazards at site
• Results of trial pits

31. Methods of quarrying
With hand tools With channelling
machine
By blasting
1) Digging/Excavating
2) Heating
3) Wedging
- For digging soft stones
- Hand tools: pick axle,
hammer, shovel, chisel, etc
- Differential expansion separates
upper layer from lower layer
- In rocks with cracks and fissures
- Steel wedges are used
- Cut channels of sufficient depth
along three sides
- There should be an exposed face
other than top face.
- Horizontal holes are driven beneath
the block from exposed face.
- Block is lifted from its bed.
Eg:- Granite, Marble
- Operations involved:
1. Boring
2. Charging
3. Tamping
4. Firing
- Produce irregular sized stones
- Explosives used to blast rocks
- When rock is hard and unfissured

33. Detonators Explosives Fuses
- Whose explosion
initiates explosion
of another
Materials for blasting
- To ignite explosives
- Used when dynamite
is used as explosive
- Fired either by fuse
or spark
- Dynamite and
Blasting powder
(Gun powder)
Charcoal
Saltpetre (KNO3)
Sulphur
Sandy powder (25%)
Nitro-glycerine (75 %)
- Use: Ordinary
quarrying works
- Uses: Tunnelling
Mining operations
Under water quarrying
- Small rope of cotton with
a core of continuous
thread of gun powder

34. Other explosives used in blasting:
1. Gelatine – 50 % more powerful than dynamite
2. Cordite – under water, no smoke
3. Gelignite – under water
4. Gun cotton
5. Liquid oxygen – large scale (mining, under water)
6. Rock-a-rock

35. • Quarried stones are cut into suitable size and shape
Dressing of stone
• To Provide pleasing appearance
• To provide good horizontal and vertical joints in masonry
• To make transportation easier
• To obtain good bonding
Types of dressing
1. Quarry dressing
2. Site dressing

36. Deterioration of stones
1. Alternate wetness and drying
2. Frost
3. Impurities in atmosphere
4. Living organisms
5. Movement of chemicals
6. Rain water
7. Temperature variations
8. Vegetable growth
9. Wind

38. Clay Products2
Ceramics Potter’s art
Articles made by the potter(‘Keramos’-Greek)
Clay products Refractories Glass
Clay Products

39. Clay
products
Bricks
Tiles
Terra-cotta
Earthenware
Stoneware
Porcelain

40. Bricks
Obtained by moulding clay
in rectangular blocks
of uniform size
and then by drying and burning.

41. Composition of brick earth:
1 Alumina 20-30 %
Chief constituent
imparts plasticity
Excess – shrinkage and warping
2 Silica 50-60 %
Prevent cracking, shrinking & warping
Imparts uniform shape to bricks
Durability of bricks depends mainly
3 Lime < 5%
Prevents shrinkage
Excess – lime melts and shape losts
4 Iron Oxide 5-6 %
Helps lime to fuse sand
Imparts red colour
Excess – blackish, less - yellowish
5 Magnesia Small quantities
Imparts yellow tint
Reduce shrinkage
Excess – decay of bricks

42. Alkalis – deform and twist brick
Harmful ingredients in brick earth
Lime – on heating converted into quick lime – brittle  crumbles
Iron pyrites
Pebbles
Vegetation and organic matter

43. Manufacturingofbricks
1.Preparation of clay
Unsoiling
Digging
Cleaning
Weathering
Blending
Tempering or pugging
2. Moulding
Hand moulding
Machine moulding
3. Drying
Natural
Artificial
4. Burning
Clamp burning
Kiln burning
Operations involved
- Removing top 20 cm clay layer
- Impurities, trees, etc are removed
- Manually or using power excavators
- Roots, pebbles, lime, organic matter
- Softening clay by adding little water
and exposing to atmosphere
- Tests for suitability
- Kneading by adding water to get a
Homogenous mass & reqd plasticity

44. Pug mil

45. 2. Moulding
Hand moulding Machine moulding
• Rectangular boxes of wood or steel
• Clay placed in the machine
• it comes out through the
opening under pressure.
• It is cut to bricks by steel
wires fixed into frames.
• Open at top and bottom
1. Ground moulded bricks
2. Table moulded bricks
1. Plastic clay machines
2. Dry clay machines
Classification:
Classification:

46. Natural Drying Artificial Drying
• To avoid cracks and distortion • To avoid cracks and distortion
• Drying by tunnels usually
1200C about 1 to 3 days
• Good circulation of air
• In a drying yard
• Machine arrangements
Wet mix contain
7-30 % moisture
3. Drying

47. 4. Burning
Clamp burning Kiln burning
Continuous
kilns
Intermittent
kilns
1. Load
2. Fire
3. Cool
4. Unload

48. Clamp burning

50. • Trapezoidal shape
• End raised at 150 from ground level
• Brick wall in mud at short end
• Alternate layers of raw bricks and fuels.
• Fuels - grass, cow dung, wood
• Air circulation spaces provided
• Total height of clamp = 3-4 m
• Plastered with mud on sides and top,
filled with earth to prevent the escape of
heat
• Burning Period = 1-2 months
• Cooling period = 1-2 months
• Burnt bricks are taken out from the
clamp

51. Advantages
• Tough and strong bricks  burning and cooling are gradual
• Cheap and economical
• No skilled labour and supervision required
• Saving of clamps fuel
Disadvantages
• Bricks are not of required shape
• It is very slow process
• It is not possible to regulate fire in a clamp
• Quality of brick is not uniform

52. Kiln burning

53. Kiln burning • A kiln is a large oven to burn bricks
• 2-3 brick row
• Trolleys used for movement of bricks
• Loading of kiln with raw bricks
• Each door is built up with dry bricks and
are covered with mud or clay
• Fire period = 48 to 60 hours
• Cool period = 12 days
• Bricks are then taken out
• Same procedure is repeated for the next
burning
Intermittent kilns

54. Advantages of kiln burning
• Bricks are evenly burnt
• Performance of this kiln is better
• Suitable for burning of structural clay tiles, terra cota  close control of
heat

55. • Rectangular, circular or oval
• Trench excavated in ground
• Widely used kiln in India
Continous kilns
Bull’s trench kiln Hoffman’s kiln Tunnel kiln
• Also called flame kiln
• Plan – circular shape
• Permanent roof provided
• Function in Rainy season also
• Form of a tunnel
• Straight, circular or oval
• Trolley transportation
• Large scale - economical

57. Comparison of clamp and kiln burning
Clamp burning Kiln burning
1 Capacity 2000 - 100000 Avg = 25000
2 Cost of fuel Low – grass, cow dung, wood High - coal
3 Initial cost Less More – Permanent structure
4 Quality Good = 60 % Good = 90 %
5 Fire regulation Not possible to control Possible
6 Skilled supervision No Yes
7 Structure Temporary Permanent
8 Suitability Small scale Large scale
9 Burning time 1-2 months 2-3 days
10 Cooling time 1-2 months 12 days

58. Unburnt bricks
IS specifications of bricks
• Sun dried bricks
(Classification)
Burnt bricks
• Used only in the
constructions of
temporary and cheap
structures
• Heavy rains - X
First class
Second class
Third class
Fouth class
• For good and permanent works
• Brick work + plastering works
• Unimp and temp structures
• over burnt bricks with irregular
shape and dark colour
• Ringing sound
• Bad ringing sound
• Rough and slightly irregular

59. 1. Free from cracks and have sharp edges
Characteristics of good brick
2. Uniform shape and size
3. Should give clear ringing sound when struck each other
4. Compact and free from voids
5. Bricks should not absorb water when soaked for 24
hours • 1st class  max = 20 percent by weight
• 2nd class  max = 22 percent by weight

60. 6. No impression when scratched
7. Low thermal conductivity
8. When fall from 1 m height  should not break
9. Crushing strength > 55 kg/cm2
10. Sound proof
Characteristics of good brick

62. Clay
products
Bricks
Tiles
Terra-cotta
Earthenware
Stoneware
Porcelain

63. Tiles
Thin slabs of bricks which are burnt in kilns
Thinner than bricks ⸫ handle carefully
Bricks may be glazed or unglazed
They are incombustible in nature
Tiles are unaffected under light

64. Manufacture of tiles
Fine clay is usedPreparation of clay
Moulding
Drying
Burning
1
2
3
4
Clay is pressed in Pattern/Shapes
Drying under a shade prevents warping
and cracking of tiles due to rain and sun
Sialkot kiln

66. Characteristics of a good tile
Free from cracks and bends1
Regular in shape and size2
Well burnt, hard and durable3
Gives clear ringing sound when struck with hand4
Fit properly when placed in position5
Uniform colour and compact structure6

67. Types of tiles
1. Roofing tiles
2. Flooring tiles
3. Wall tiles
4. Partition tiles
5. Pavement tiles
6. Drain tiles
Based on application Material & Manufacture
1. Ceramic tiles
a) Earthenware tiles
b) Terracotta and faience
c) Fully vitrified tiles
d) Glazed tiles
e) Stoneware Tile
2. Porcelain tiles
3. Mosaic tiles
4. Natural stone tiles

68. 1. Roofing tiles
To keep out rain
Shelter
Made of clay/slate
Modern materials :
concrete and plastic
Eg: Flat tile
Eg: Flat tile
Types of roofing tiles
Allahabad tiles1
Corrugated tiles2
Flat tiles3
Manglore tiles4
Pan tiles5
Pot tiles5
Semi-circular
Double channeled
Basel Mission
Manglore Pattern

69. 2. Floor tiles 3. Wall tiles
Made of ceramic, stone,
or glass
Available in various
textures
Interior and exterior
walls
Decoration purpose
Toilets
Used for flooring works
Flat in shape
4. Drain tiles
Drain water through it
Tiles with holes
Porous
Avoids flooding of water

70. 5. Partition tiles 6. Pavement tiles
Used for partition of spaces in a room
Thinner partitions
Sub divide areas into room
Used as pavements
Provision for drainage
Also called as inter-locks

71. 1. Ceramic tiles
Clay, sand, and other natural substances.
Commonly used in residential buildings
Mainly used in interior walls and floors
Ceramic coating
Clay

72. 2. Porcelain tiles
A type of ceramic tiles
Clay grains used are finer than ceramic tiles
Mainly used in interior walls and floors
Fired at higher temperature than ceramic tiles
Denser, less porous and more resistant to
moisture and stains than ceramic tiles
Suitable for both indoor and outdoor works
Harder, but low water absorption

73. Vitrified tiles Glazed tiles
Clay + quartz + feldspar + silica
Alternative to marble and granite
flooring
Liquid glass coating of
thickness 0.1 - 0.2 mm
Stain resistant
Ceramic tile with very low porosity
Easy to clean
Fade resistanceCeramic material in full thickness
Ceramic coating
Clay Vitrified tiles

74. 3. Terra-cotta
Terra – “earth”, cotta – “based”
Also called as “Baked earth”
Clay product made by careful burning
A kind of earthware which is soft and porous
High Alumina and iron oxide content
Less proportion of sand and lime

75. Manufacture of terra-cotta
Crushed pottery usedPreparation of clay
Moulding
Drying
Burning
1
2
3
4
Zinc + Plaster of paris
Muffle furnace

77. Varieties of terra-cotta
1. Porous terra-cotta
2. Polished (fine) terra-cotta
Wood powder/saw dust added
Fire and sound proof
Also known as fine terra-cotta or Faience
Ornamental purpose
terra-cotta
Biscuiting
Heating at 650oC Immerse in
glazing compounds
Heating at 1200oC
Top surface glazed
Salt/lead solution

78. Earthenware
Ware means articles
Clay + Sand + Crushed pottery
Generally soft and porous
Clay burnt at low temperature and cooled slowly
Terra-cotta is a kind of earthenware
Uses: Ordinary drain pipe, pottery, vessels

80. Stoneware
Generally Hard and non-porous
Clay burnt at high temperature and cooled slowly
Uses: Sanitary appliances, closets, wash basins, pipes
Can easily clean

81. Attribute Earthenware Stoneware
Temperature of
baking
low high
Cooling Slowly Slowly
Porosity Porous Non-porous
Hardness Soft Hard
Durable Less More
Expense Less More
Comparison of Earthenware and Stone ware

82. Porcelain (Whiteware)
Clay + felspar + Quartz + minerals
Fine earthenware – white and semi transparent
Uses: Sanitarywares, electric insulators, storage vessels
Hard, brittle and non-porous
Two types
1. Low voltage porcelain – prepared by dry process
2. High Voltage porcelain – prepared by wet process

84. 84
• Important cementing material
• Used in old times instead of cement
• Uses:
Ordinary buildings
Massive monuments
Palaces
Forts
• Chemically: CaO
Lime

85. 1. Limestone hills
2. Seashells
3. Corals
4. Kankar (Below ground level)
5. Beds of old rivers
Sources of lime

86. Important technical terms
1. Calcination
Heating to redness in presence of air
2. Hydraulicity
Ability to set in presence of water and in absence of air
3. Lime
CaCO3 CaO + CO2
Calcination
(Limestone) (Lime)
Note: CaCO3  Most stable form of lime
Impurity in lime = clay

87. Important technical terms
4. Slaking
Chemical reaction occurring when water is added to lime
5. Setting
Process of hardening of lime after it has been converted
into paste form.
Ca(OH)2CaO + H2O Slaking
(Slaked lime)(Lime)
Note: Slaked lime is used for white washing

88. Manufacture of fat lime

89. Classification
1. Quick (Fat/pure) lime
2. Hydraulic (Slaked) lime
3. Poor (lean) lime
Class A
Class B
Class C
Class D
Class E
Based on clay content BIS Classification

90. 1. Quick (Fat/Pure/Caustic) lime
Product left immediately after calcination of pure lime stone
Clay content – less than 5 %
Also known as white lime, rich lime, high calcium lime, etc
When slaked, volume increases by 2-2.5 %
No hydraulicity
To get hydraulicity, add Surkhi (powder of burned bricks)

91. 2. Hydraulic (Slaked/water) lime
Clay content – 10 to 30 %
Feebly H.L Moderately H.L Eminently H.L
Clay content – 5 to 10 %
Slaking is faster
(few minutes)
Setting is slow (3 week)
Used for ordinary
masonry works
Clay content – 11 to 20 %
Slakes after 1 to 2 hours
Setting is moderate
(1 week)
Used for superior type
masonry works
Clay content – 21 to 30 %
Slakes with difficulty
Setting is fast (1 day)
Used for under water
works, damp places, etc
More strength (Similar to
ordinary cement)

92. 3. Poor (lean lime)
Also known as “impure lime”
Clay content – greater than 30 %

93. BIS Classification of lime
1. Class A
2. Class B
3. Class C
4. Class D
5. Class E
6. Class F
- Eminently H.L – Structural purposes
- Semi H.L – Masonry works
- Fat lime – White washing
- Mg/Dolomite lime – finishing coat in plastering
- Kankar – masonry mortar, soil stabilization
- Silicious dolomite lime – under coat and finishing
coat in white washing

95. Cement - Any substance which acts as a
• Invented by Joseph Aspidin
• Obtained by burning and crushing of stones
• Resembles natural lime
Cement
binding agent for materials

96. Ingredients and Sources
Lime : limestone, chalk, shells, shale or calcareous rock
Silica : from sand, old bottles, clay or argillaceous rock
Alumina : from bauxite, recycled Aluminum, clay
Iron : from clay, iron ore, scrap iron and fly ash
Gypsum : found together with limestone

97. Ingredients in cement
1 Lime CaO 62 %
• Binding property and strength
• excess makes cement unsound
• Deficiency – Quick setting of cement
• Lime ↑ Slow setting
2 Silica SiO2 22 %
• C2S, C3S – Strength contribution
• Excess – Strength ↑ , Prolong setting time
3 Alumina Al2O3 5 %
• imparts quick setting property
• Act as a flux to reduce clinkering
temperature (2000oC  1500oC)
• Produce more heat at time of hydration
4 Calcium Sulphate CaSO4 4 %
• Gypsum - increase the initial setting time
• Added to rotary kiln at time of final grinding
5 Iron oxide Fe2O3 3 % • imparts colour, Hardness and strength
6 Magnesia MgO 2 % • Yellowish tint, excess  unsound
7 Sulphur S 1 % • excess makes cement unsound
8 Alkalies … 1 % • Excess cause efflorescence

98. Bogue’s compounds
1 Dicalcium silicate (Belite) C2S 2CaO.SiO2
2 Tricalcium silicate (Alite) C3S 3CaO.SiO2
3 Tricalcium aluminate (Celit) C3A 3CaO.Al2O3
4 Tetracalcium aluminoferrite (Felit) C4AF 4CaO. Al2O3.Fe2O3

99. Chemical composition of cement
1 Tricalcium aluminate (Celite) C3A 10 %
First formed – within 24 hours
No strength contribution
2 Tetracalcium aluminoferrite C4AF 8 %
2nd formed – within 24 hours
No strength contribution
3 Dicalcium silicate (Belite) C2S 20 % Progressive strength
4 Tricalcium silicate (Alite) C3S 55 % Early strength
5 Sodium oxide Na2O < 2 %
6 Potassium oxide K2O < 2 %
7 Gypsum CaSO4.2H2O 5 % Control setting time of cement

100. Manufacturing of cement
Mixing of raw materials
Burning
Grinding
1
2
3

101. Calcareous material
(Lime stone)
Argillaceous material
(Clay)
Crushing
Ball mill
Tube mill
Storage
basin
Grinding
Crushing
Ball mill
Tube mill
Storage
basin
Mixing of
raw materials Grinding
1
Mixing in correct proportion
Pre-heating @ 800oC
Storage tank

102. Burning2
Heated air
Raw
materials
Clinker
3-20 mm
95oC
1
25
(1 in 25 to 1 in 30)
Clinker
forming
temperature
Cooling zone

103. Rotary kiln

105. Grinding3
Add 4 % gypsum
Ball mill (large balls)
Tube mill (Small balls)

106. Calcination - Burning a mixture of calcareous and
argillaceous material at very high temperature
in correct proportion.
Calcined product = CLINKER
CLINKER + Gypsum = cement

107. Characteristics of cement
High compressive strength
Flexible and easy mouldable
Easy to handle and use
Good binding property
Cement never gets rusted
Cement is a bad conductor of electricity

108. Types of cement
1. Ordinary Portland Cement
2. Rapid Hardening Cement
3. Extra Rapid Hardening Cement
4. Sulphate Resisting Cement
5. Portland Slag Cement
6. Quick Setting Cement
7. Super Sulphated Cement

109. 8. Low Heat Cement
9. Portland Pozzolana Cement – fly ash based and calcined clay based
10. Air Entraining Cement
11. Coloured Cement (White Cement/Snowcem)
12. Hydrophobic Cement
13. Masonry Cement
14. Expanding Cement
15. Rediset Cement
16. High Alumina cement

110. Ordinary Portland Cement (OPC)
Grades
• 33 Grade  min 33 N/mm2 strength (M20)
• 43 Grade  min 43 N/mm2 strength (Normal RCC works)
• 53 Grade  min 53 N/mm2 strength
 For > M30
 Can reduce cement by 10 – 15 %
 Can reduce steel by 5 – 8 %
 High rise buildings, chimney, etc
1

111. Rapid Hardening Cement
• Speedly (rapidly) attains strength (3 days)
• Initial and final setting time same as OPC
• Higher C3S and lower C2S content
early stage strength
(56 %)
• pre-fabricated concrete construction
• Road repair works
• Where speed of construction is needed
Progressive strength
2

112. Extra Rapid Hardening Cement
• RHC + Calcium chloride
• Transported, placed, compacted & finished within about 20 minutes
• Accelerates the setting and hardening process
• Strength 25 % higher than RHC
Uses
• Concreting in cold weather
3

113. Sulphate Resisting Cement
• Resistant to sulphate attack
• low C3A content (below 5 % only)
• Has high silicate content  High sulphate resisting ability
Uses
• Sewage treatment works, marine structures
4

114. Portland Slag Cement
• OPC + Granulated blast furnace slag
• Low heat of hydration
• Resistance to chemical attacks
• Resistance to corrosion of steel reinforcement
Uses
• RCC
5

115. Quick Setting Cement
• Sets fastly
• Alumnina ↑
• Gypsum ↓
• Initial setting time = 5 minutes
• Final setting time = 30 minutes
Uses
• Pumping Concrete works
6

116. Super Sulphated Cement
• Granulated slag + gypsum + 5 % Portland cement clinker
• Low heat of hydration
• High sulphate resistance
Uses
• Marine works
7

117. Low Heat Cement
Uses
• Dams, mass concrete works
8
• Opposite of high alumina cement
• Less heat is produced at time of hydration
• Low C3S , C3A reduced
• Slow rate of gain of strength
• Same ultimate strength of OPC
• Initial setting time = 1 hour
• Final setting time = 10 hour

118. Portland Pozzolana Cement (PPC)
• OPC clinker + 10 - 35 % pozzolanic material
• Clinker replaced by cheaper pozzolanic material (Fly ash or Calcined clay)
• PPC gives more volume of mortar than OPC.
• Longer setting times
• Sulphate resistant
• Less compressive strength at early stages
Uses
• Sewage works, under water works, normal works
9

119. Hydrophobic Cement
• Afraid of water !!
• Reduces wetting ability of cement
• Helps to reduce w/c ratio
• Contains admixtures – Acidol
- Napthene soap
- Oxidized petrolatum
• frost and water resistance
10

120. Acid resistant cement11
• Binding material : Soluble gas
• Do not resist water
To resist water add
0.5 % linseed oil or
2 % ceresit

121. Coloured cement (Snowcem)12
5 – 10 % pigment
Chromium oxide - Green
Cobalt - Blue
Manganese dioxide – Black/Brown
Expanding cement13
Expanding agent: Sulpho Aluminate

122. High Alumina cement14
Alumina ↑ – 32 % - Quick setting
Initial setting time = 3
𝟏
𝟐
𝐡𝐨𝐮𝐫𝐬
Final setting time = 5 hours
Less time, more strength
In England  Cement Fondu
In America  Lumnite
By fusing Lime stone + Bauxite, Gypsum not added

123. Properties of cement
• Binder material (adhesive and cohesive property)
• On adding water Hydration (Exothermic reaction-Heat)
• Fineness < 10 % of its original weight
• Initial setting time of OPC = 30 min
• Final setting time of OPC = 600 min
• Specific gravity of OPC = 3.15
• Normal consistency for OPC ranges from 26 to 33%

124. Tests on cement
Field tests Laboratory tests
1. Fineness
2. Specific gravity
3. Consistency
4. Setting time
5. Soundness
6. Compressive strength
7. Tensile strength

125. Field testing of cement
1. Open the bag and take a good look at the cement
- no visible lumps.
2. Colour = Greenish grey
3. Should get a cool feeling when thrusted
4. When we throw the cement on a bucket full of
water, before it sinks the particle should flow

126. 1
Degree to which the cement is grinded
into smaller and smaller particles
Fineness Test on Cement
Using 90 micron IS Sieve
Air permeability method

127. Apparatus required:
IS Sieve 90 micron weighing balancecement
Hydration of cement
During mixing of cement with water, chemical
reaction take place between them. Heat is liberated.

128. 1.Break down any air-set lumps in the cement
sample with fingers.
2.Weigh 100 grams of cement in IS 90 micron
3.Continuously sieve the sample for 15 minutes
4.Weigh the residue left after 15 minutes of sieving.
5.This completes the test.
Procedure

129. Fineness =
𝑨
𝑩
x 100
A = Weight of cement retained on 90 micron IS sieve
(15 minutes)
B = Total weight of sample
Rule in this experiment
For ordinary Portland cement (OPC) fineness should not be more
than 10 % of original weight as per IS code.

130. weight of a given volume of the cement
weight of equal volume of water
Standard value: 3.15
Gc =
2 Specific gravity of cement

131. Apparatus required:
Specific gravity bottle weighing balance

132. w1 = weight of empty bottle
w2 = weight of bottle + cement
w3 = weight of bottle + cement + kerosene
w4 = weight of bottle + kerosene full
w5 = weight of bottle + water
w1 w2 w3 w4 w5

133. Gk =
weight of kerosene
𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑤𝑎𝑡𝑒𝑟
=
Specific gravity of the kerosene
w4 − 𝑤1
𝑤5 − 𝑤1
Specific gravity of the cement
Gc =
𝐰𝐞𝐢𝐠𝐡𝐭 𝐨𝐟 𝒄𝒆𝒎𝒆𝒏𝒕
𝒘𝒆𝒊𝒈𝒉𝒕 𝒐𝒇 𝒂𝒏 𝒆𝒒𝒖𝒂𝒍 𝒗𝒐𝒍𝒖𝒎𝒆 𝒐𝒇 𝒌𝒆𝒓𝒐𝒔𝒆𝒏𝒆
Gc =
𝐰 𝟐
−𝒘 𝟏
𝒘 𝟒
−𝒘 𝟏
−(𝒘 𝟑
−𝒘 𝟐
)
x Gk

134. Standard/Normal Consistency
Initial Setting time
Final Setting time
Standard Plunger (10 mm dia, 50 mm long)
Square needle (1 mm)
Needle with annular collarVicat Apparatus

135. Relative mobility of a freshly
mixed cement paste
Ability of cement to flow.
Easiness of work with cement
3 Standard consistency of cement

136. Vicat apparatus
weighing balance
Trowel
Apparatus required:

139. 400 g cement 25 % water by
weight of dry cement
+
Generally normal consistency for
OPC ranges from 26 to 33%.
Cement paste
Repeat the process till the standard consistency
(Water % for 33-35 mm penetration from top) is got
Gauging time
( 3-5 minutes)

140. 1. Take 400 g cement
2. Add 25 % water by weight of dry cement
3. Prepare cement paste within 3-5 minutes (Gauging time)
4. Fill in Vicat mould
5. Attach standard plunger above the test block
6. Release plunger and note depth of penetration
7. If penetration ranges from 33-35 mm from top, it is standard
consistency for given cement.
8. Else add 1 % more water and repeat the experiment till we get
standard consistency.
Procedure

141. The time elapsed between the moment water is added to
the cement to the time at which cement paste starts
losing its plasticity.
Initial setting time:
For OPC > 30 minutes
4 Initial and final setting time

142. The period elapsing between the time water is added to
the cement and the time the needle makes an impression
on the surface of the test block
Final setting time:
For OPC < 10 hours or 600 minutes

143. 1. Take 300 g cement
2. Add 0.85 times water required for standard consistency
3. Start stop watch
4. Prepare cement paste within 3-5 minutes (Gauging time)
5. Fill in Vicat mould
6. Attach square needle above the test block
7. Release square needle. In beginning needle penetrates completely.
8. Paste starts losing its plasticity.
9. Release after half an hour, the needle penetrates 33-35 mm from top.
Stop watch and note the time (initial setting time).
10.Replace needle with annular collar needle. Check after 10 hours.
11.Note the no impression forming time (final setting time).
Procedure

144. • Reason: insufficiency in grinding, burning, etc
• Soundness = Ability of hardened cement paste to
retain its volume after setting without expansion.
 Cement does not undergo any large expansion
• Ensures:
 To detect the presence of excess lime in
cement
5 Soundness test

145. • Le Chatelier test detects unsoundness due to free lime only
• If expansion of cement > 10 mm
• Unsound
• Excess lime  Cracks
• Expansion should be less than 10 mm
• OPC – Ordinary Portland Cement
• RHC – Rapid Hardening Cement
• Low Heat Portland Cement

146. Take a
sample of
100
grams
cement.
Paste
0.78 x P
Cover
with
glass
sheet
Fill in Le chatelier apparatus
Immerse in water, 24 hrs, 270C
Note the distance b/w pointers
before boiling – d1
Boil 3 hrs – reach boiling
point within 25-30 minutes
Note the
distance b/w
pointers after
boiling – d2
Cool
Expansion = d2 – d1

148. 6 Compressive strength of cement
• Cube size = 7.06 X 7.06 X 7.06
• Face area = 50 cm2

149. Uses of cement
Mortar for plastering
Masonry works
Pointing works
Floors, roof, beam, column, footing, lintel, etc
For construction of engineering structures
For making concrete for various structures
Crack filling

151. Pozzolana
A natural siliceous and aluminous material
Pozzolana + Calcium Hydroxide  Pozzolanic reaction
Have binding/cementitious property
Formed from volcanic ash/other means
Portland cement contains pozzolanas
Eg:- Surkhi, blast furnace Slag, Rice husk ash

152. Common puzzolonas used as admixtures in cement
1. Surkhi
2. Blast furnace Slag
3. Fly ash
4. Silica Fume
5. Rice- husk Ash
- Brick dust
- Waste of iron manufacturing
- Burning of coal
- Byproduct of silicon

153. Geological
origin
Size Shape Unit weight
1.Natural aggregates
• Igneous
• Sedimentary
• Metamorphic
2.Artificial aggregates
• Blast furnace
slag
1.Coarse
> 4.75 mm
2.Fine
< 4.75 mm
1.Rounded
2.Irregular
3.Flaky
4.Angular
1.Normal weight
2.Heavy weight
3.Light weight
Aggregates

154. Sand
• Sand basically consists of Silica (SiO2)
• Formed by decomposition of sandstone due to weathering action.
Types/sources of Sand
1. Pit sand - angular shape
2. River sand – round shape
3. Sea sand – from sea shore. Contain salts.
4. Sand dunes – desert sand
• Also called as adulterant

155. Classification of sand
1. Fine sand < 1.5875 mm
2. Coarse sand < 3.175 mm
3. Gravelly sand < 7.62 mm

156. Limitations of mining of sand from
rivers and sea shore
• Disturbs natural equilibrium
• Problems to bridges
• Problems to fishes and river inhabitants
• Contamination of river water
• Affects quality of river water

157. Alternatives of sand
• Plastering Sand (P Sand)
• Processed Quarry Dust
• Offshore Sand
• Dune Sand
• Slag Sand
• Construction Demolition Wastes
• Manufactured Sand (M Sand)

158. M-sand
• Manufactured sand
• Alternative to river sand
• Cost of construction is less
• Low water absorption
• Manufactured by crushing of rocks
• In reality, better than river sand.

159. Coarse aggregates
• Size > 4.75 mm
• Major contribution to strength in concrete
• Influences workability & degree of compaction of concrete
• Materials generally used are :
1. Gravel
2. Crushed stone
3. Slag
4. Recycled concrete
5. Geo-synthetic aggregates

160. Requirements of good coarse aggregates
• Hard, strong and durable
• Free from organic impurities
• Free from grass and roots
• Clay content < 4 %
• Resistance to change in volume
• Well graded

161. Commonly used sizes for different applications
• Roads = 40 mm
• Column and slab = 20 mm
• Self compacting concrete (SCC) = 10 mm
• Retaining walls and abutments = 75 mm
• Concrete dams = 75 mm
Different based on type of work. Commonly used are

162. Grading of coarse and fine aggregate
• Particle size distribution of aggregates
• Measured by sieve analysis method
• Described using Grading curve
Gives ‘cumulative % passing’
against standard IS Sieves
• Influences workability & degree of compaction

163. • Poorly graded  All particles of aggregate
have same size – more voids
• Well graded  Contains particles of all sizes (GOOD)
• Gap graded  Some big, some small particles.

164. Mortar (Matrix)
• Composite mixture
• Cement + Sand + water (No coarse aggregate)
• Used in plasterings, masonry, etc
Concrete
• Composite mixture
• Easily mouldable
• Cement + Sand + Coarse aggregate + water
• Used in beams, columns, slabs, footings, stairs, etc

165. Functions of sand in mortar
1. Void filler
2. Bulking – Sand bulks  volume of mortar increases  Thus cost reduced.
3. Setting – setting of fat lime occurs effectively due to sand
4. Shrinkage – sand prevents excessive shrinkage of mortar & prevent cracking
5. Strength – helps in adjustment of strength by varying its proportion.

166. Preparation of lime mortar
Prepared by grinding or pounding
1 - Grinding – for large quantities of lime mortar
2 - Pounding – for preparing small quantities

167. Preparation of cement mortar
Does not require grinding or pounding
Cement and sand are mixed in required proportions in
dry state on a watertight platform
Add water and mix thoroughly

168. Proportions of mortar for various items of work
No Nature of work Mortar proportion
1 Construction work in waterlogged areas and exposed positions 1:3
2 Damp proof courses and cement concrete roads 1:2
3 General RCC work such as lintels, pillars, slabs, stairs etc 1:3
4 Internal walls 1:3
5 Partition walls and parapet walls CM 1:3 or LM 1:1.
6 Plaster work (finishing mortar) 1:3 to 1:4
7 Pointing work 1:1 to 1:2
8 Brick laying mortar 1:6 to 1:8

169. Tests for mortar
Adhesiveness to building units
Crushing strength
Tensile strength
1
2
3

170. 1. Adhesiveness to building units
1. Place two bricks at right angles
2. If size of brick is 19 x 9 x 9 cm brick, a
horizontal joint 9 cm x 9 cm = 81 cm2 is formed
3. The upper brick is suspended from an overhead
support and weights are attached to lower brick
4. Weights are gradually increased till separation
of brick occurs
Ultimate adhesive strength = Maximum load
81

171. 2. Crushing strength
1. Prepare a brickwork with mortar
2. Apply gradual load to this sample brickwork till failure occurs
by crushing.
Ultimate Crushing strength = Maximum load .
Cross sectional area

172. 3. Tensile strength
1. Mortar is placed in briquette mould
2. Briquettes are tested in a tension
testing machine

173. Cement Concrete ingredients
Concrete
Cement Binder
Coarse aggregate Strength
Fine aggregate Void filler
Water
Hydration
Workability
Curing
Admixtures Chemicals

174. Manufacture of concrete

175. Proportioning/Batching concrete
Process of selection of relative proportions of
cement, sand, coarse aggregate and water so as to
obtain a concrete of desired quality.
Process of measuring concrete mix ingredients either
by mass or volume and introducing them into the
mixer.

176. Types of Proportioning
1. Volume batching
2. Weight batching
• Small jobs
• Accurate and uniform proportioning

177. PCC and RCC
PCC – Plain Cement Concrete – no rebars
RCC – Reinforced Cement Concrete
Structural concrete
• Concrete + steel bars
• Tensile strength of concrete = 7–15 % of compressive strength

178. Functions of water in concrete:
• Potable water (drinking water can be used) is used in concrete.
• Water makes the concrete workable
• Amount of water controls Hydration
• Amount of water controls Curing
• Defines strength of concrete
• Defines shrinkage of concrete
Water lubricates aggregates and facilitates passage of cement through voids.

179. Water-cement ratio
Amount of water
Amount of cement by weight
w/c ratio =
• Ratio of weight of ‘free water’ (excluding that absorbed
by aggregates) to cement in a mix.
• Strength and quality of cement concrete primarily
depends on w/c ratio
• Strength and quality of cement concrete primarily
depends on w/c ratio

180. Abrams Law
Water-cement ratio is inversely proportional to compressive
strength of concrete.
 Low w/c ratio is good

181. Advantages of low w/c ratio
• Increases compressive strength
• Lower permeability
• Increased resistance to weathering
• Better bond b/w concrete and reinforcement
• Reduce shrinkage and cracking

182. Advantages of low w/c ratio
• Increases compressive strength
• Lower permeability
• Increased resistance to weathering
• Better bond b/w concrete and reinforcement
• Reduce shrinkage and cracking

183. Characteristics of concrete
Unit weight = 25 kN/m3
Compressive strength Eg:- M20, MMix, 20  fck = 20 MPa
Increase in strength with age
Tensile strength of concrete Flexural strength, fcr = 0.7 √fck N/mm2
Elastic Deformation Ec = 5000 √fck N/mm2
Shrinkage of concrete Strain = 0.0003
Creep of concrete
Thermal expansion of concrete

184. Characteristics of reinforcement
Unit weight = 7850 kg/m3
Modulus of Elasticity, E = 2 x 105 N/mm2
Poisson ratio, 𝝁 = 𝟎. 𝟑
Should bond well with concrete
Should have good strength
Should have good ductility
Should have good resistance against corrosion

185. Concrete grade and mix ratio
Mix Mix ratio Nature of work
M 5.0 1:5:10 Mass concrete for heavy walls,
footings, etc
M 7.5 1:4:8 Mass concrete – foundations of
less importance
M 10 1:3:6 Mass concrete – foundations of
less importance
M 15 1:2:4 General RCC works (Slab, beam,
column, etc)
M 20 1:1.5:3 Water retaining structures, piles,
and general RCC works
M 25 1:1:2 Heavy loaded RCC structure –
long span slabs, beams, etc

186. Workability
Property of freshly mixed concrete (or mortar) which
determines the ease and homogeneity with which it
can be mixed, placed, compacted and finished.
Ability to flow and work with concrete

187. Factors affecting workability
• Water content
• Size – finer particles  more water  large specific surface
• Texture and grading
• Shape – Angular aggregates require more water than rounded aggrgates
• Mix proportions
• Grading of aggregates
• Use of admixtuers

188. Workability tests
1. Slump test
2. Compaction – factor test
3. Vee-bee test

189. • Field and lab test to find workability of fresh concrete
Slump test

190. Slump
The difference in height between the concrete before
removing slump cone and height of the concrete after
removing of slump cone

191. Types of slump
1. Zero slump – no slump when slump cone is removed
2. Collapse slump
3. Shear slump – some portion subsides largely
4. True slump

192. 1. Prepare mix and fill slump cone in 3 layers – 25 times
tamping to each layer
2. Cut the excess concrete and level the top
3. Remove the slump cone slowly
4. Measure the slump : Max slump = 300 mm
Procedure for slump test

193. • Field and lab test
Compaction factor test
Prepare mix. Eg: M20
A
B

194. • Fill concrete in HOPPER A
• Open trap door  Concrete falls to HOPPER B
• Open trap door  Concrete falls to CYLINDER
• Note the weight of partially compacted concrete
• Remove all concrete from cylinder – EMPTY IT
• Again fill the cylinder from same sample mix
• 3 LAYERS – 25 Tamping with tamping rod
• Weight the fully compacted concrete
• Compaction Factor is
C.F =
𝐖𝐞𝐢𝐠𝐡𝐭 𝐨𝐟 𝐩𝐚𝐫𝐭𝐢𝐚𝐥𝐥𝐲 𝐜𝐨𝐦𝐩𝐚𝐜𝐭𝐞𝐝 𝐜𝐨𝐧𝐜𝐫𝐞𝐭𝐞
𝐖𝐞𝐢𝐠𝐡𝐭 𝐨𝐟 𝐟𝐮𝐥𝐥𝐲 𝐜𝐨𝐦𝐩𝐚𝐜𝐭𝐞𝐝 𝐜𝐨𝐧𝐜𝐫𝐞𝐭𝐞
Procedure for compaction factor test

195. Reinforced Cement Concrete (RCC)
• Concrete is good in resisting compression, but
weak in taking tension.
• So reinforced bars provided where tension occurs
• Cement + Sand + Coarse aggregate + water + rebars
• Used in beams, columns, slabs, footings, stairs, etc
• Concrete take compression and rebars takes tension

196. Qualities of reinforcing material
• Easily available in bulk and economical
• High tensile stress and elasticity
• Good durability
• Should be corrosion resistant
• Good bonding with concrete
• Thermal coefficient of expansion should be
nearly equal to that of concrete to minimise
thermal stress

197. Steel and types
Steel
Mild steel Fe 250
HYSD bars
Fe 415, Fe 415 D
Fe 500, Fe 500 D
Fe 600
TMT
Thermo Mechanically
TreatedHigh Strength Steel

198. Types of reinforcement used
1. Hot Rolled Deformed Steel Bars
2. Cold Worked Steel Bars
3. Mild Steel Plain Bars
4. Prestressing Steel Bars

199. 1. Hot Rolled Deformed Steel Bars
Mostly used for RCC structures
Certain ribs (deformations) on steel surface
These ribs helps to develop good bond with concrete

200. 2. Cold Worked Steel Bars
Bars undergo twisting and drawing in cold working process
3. Mild Steel Plain Bars
Do not have ribs on their surface – plain surface
Used for small projects - economical

201. 4. Prestressing Steel Bars
In form of tendons
Cold formed and have a high tensile strength

202. Tests on Hardened concrete
1. Compression test (cube & cylinder)
2. Flexural strength test
3. Split tensile strength test

203. Compression test - cube
• 3 cubes – 15 X 15 X 15 cm
• Mould removal – after 1 day
• Curing – 3, 7, 28 days
• Tested using UTM/CTM

204. Compression test - Cylinder

205. Flexural strength test

206. Split tensile strength test

207. Chemical admixtures
1. Plasticizer
2. Superplasticizer
3. Accelerators
4. Retarders
5. Air entraining admixtures
6. Water-reducers
Chemicals added to concrete before or during
mixing of concrete to modify some specific
property of fresh or hardened concrete.
Eg:-

208. Plasticizers and super plasticizers
• A type of water reducing admixture
• Also called as High range water reducer
• Increased fluidity : flowing, self levelling, etc
• Reduced water cement ratio: High early strength
• Commonly used superplasticizers are
1. Sulphonated melamine formaldehyde condensates (SMF)
2. Sulphonated naphthalene formaldehyde condensates (SNF)
3. Polycarboxylate ether superplasticizers (PCE)

209. • A type of admixture
• Increase rate of hydration of cement
• Reduce setting time
• Increase rate of strength development
• Eg:- Na2SO4, NaCl, K2SO4, CaCl2
Accelerators

210. • To increase (retard/delay) the setting time
• Slow rate of hydration
• Helpful – concrete transporting to long distance
• Eg:- Derivatives of sugar and carbohydrates,
gypsum, plaster of paris, etc
Retarders

211. Timber and wood products

212. Timber
Timbrian = build
Timber means wood suitable for building /
carpentry / engineering purposes
Standing timber
Rough timber
Converted timber
Timber contained in a living tree
Obtained after felling a tree
Timber sawn & cut into suitable commercial sizes

213. Classification of trees
Exogenous Endogenous
(Grow outwards) (Grow inwards and longer)
Conifers Deciduous
Used for engg
purposes
Eg: - Bamboo, cane,
palm, coconut tree
 Ever green trees
 Leaves do not fall till new
ones grows
 Bears cone shaped fruits
 Eg: Mango tree
Soft wood
 Broad-leaf trees
 Leaves fall in autumn and
new ones appear in spring
 Mostly for engg purposes
 Eg: Teak
Hard wood

214. Soft wood | Hard wood
• Ever green trees
• Distinct annual rings
• Light colour
• Poor fire resistance
• Indistinct medullary rays
• Can split easily
• Light weight
• Broad-leaf trees
• Indistinct annual rings
• Dark colour
• More fire resistance
• Distinct medullary rays
• Can’t split easily
• Heavy weight

215. Structure of a tree
1. Micro structure
2. Macro structure
Timber studied under microscope
Timber studied with naked eye

216. Micro structure
Timber consists of living and dead cells
Living cells – membrane, protoplasm, sap, core
1. Conductive cells
Transfer nutrients from roots to various parts of tree
2. Mechanical cells
Tightly interconnects cells and imparts strength to tree
3. Storage cells
Extra nutrients are stored

217. Macro structure

218. Pith (core/medulla)
Heart wood
Sap wood (Albernum)
 Innermost central portion
 Inner annular rings surrounding pith
 Usually dark in colour
 Used for engineering purposes
 Outer annular rings b/w heart wood and cambium layer
 Light weight and light colour
 It take active part in growth of tree
 Supply nutrients at young age

219. Cambium layer
 Thin layer of sap b/w sap wood
and inner bark
 This get converted into sap wood
Inner bark
 Inner layer covering (protection to) cambium layer
Outer bark (Cortex)
 Outermost protective layer of a tree
Medullary rays
 Thin radial layers extending from pith to cambium layer
 Hold together annual rings of heart wood & sap wood.

220. Defects in timber
Conversion Fungus Natural forces Insects Seasoning
1. Chip mark
2. Diagonal grain
3. Torn grain
4. Wane
1. Blue stain
2. Sap stain
3. Dry rot
4. Wet rot
5. Brown rot
6. White rot
7. Heart rot
1. Burls
2. Callus
3. Chemical stain
4. Coarse grains
5. Dead wood
6. Druxiness
7. Foxiness
8. Knot
9. Rind gall
10.Shake
1. Cup shake
2. Ring shake
3. Heart shake
4. Star shake
5. Radial shake
11.Twisted Fibre
12.Upset or rupture
13.Water stain
14.Wind crack
1. Beetles
2. Marine borers
3. Termites
1. Check
2. Split
3. Cup
4. Bow
5. Twist
6. Warp
7. Collapse
8. Case hardening
9. Radial shake
10.Honey combing
due to

221. 1. Defects due to conversion
Marks/signs placed by chips on finished timber surface
1. Chip mark
May be formed by parts of planing machine, chisel marks, etc
Due to improper sawing of timber
2. Diagonal grain
Affects appearence
Not affects strength
Should cut parallel to layers/fibers
Don’t cross fibers while cutting

222. When heavy equipments falls on a finished surface,
depressions are formed.
3. Torn grain
Due to improper sawing of timber
4. Wane
Not affect strength, but affect appearence

223. 2. Defects due to fungus
Fungus attacks timber if
(i) moisture content > 20 % and
(ii) in presence of air.
Wood submerged in water will not affected by fungus
Wood having moisture content < 20 % will not affected
by fungus

224. 3. Dry rot
Certain fungus attack timber and convert it into powder form
4. Wet rot
Some fungus causes chemical decomposition of wood
that convert timber into greyish brown powder.
1. Blue stain
Sap of wood is stained to bluish colour by action of fungi
2. Sap stain
Sap wood losses its colour due to fungus attack.

225. 5. Brown rot
Rot means decay/disease of timber
Some fungus attacks cellulose  White colour losses.
Thus brown colour of lignin dominates and wood seen
as brown colour.
6. White rot
Some fungus attacks lignin  Brown colour losses.
Thus white colour of cellulose dominates and wood seen
as white colour.

226. 7. Heart rot
Formed when branches are cut
Heart wood is exposed to attacks of atmospheric agents
Tree becomes weak; it gives us hollow sound when
stuck with a hammer.
Fungus develops holes in timber

227. 3. Defects due to natural forces
1. Burls
When tree gets shock/injury in its young age
Also known as excrescences
Due to such injury, growth of tree becomes completely
upset and irregular projections appear on the body of
timber.
2. Callus
Soft tissue or skin which covers the wound of a tree

228. 3. Chemical stain
Wood sometimes discoloured by chemical actions.
4. Coase grain
If a tree grows rapidly, annual rings are widened.
Have less strength
5. Dead wood
Timber obtained from dead standing trees

229. 6. Druxiness
White decayed spots concealed by healthy wood
7. Foxiness
Red or yellow tinge in wood
Due to
(i) Bad ventilation
(ii) Over maturity

230. 8. Knot
Bases of cut-off branches of a tree
Continuity of wood fibre is lost due to knots  Weak
Dark and strong (even saw breaks)
Losses alignment of fibers

231. 9. Rind galls
Rind means bark; gall means abnormal growth
Develops at points from where branches are
improperly cut-off.
Nutrients get still supplied at that points
Fibers gets cutted

232. 10. Shakes
Cracks formed in annual ring direction
a) Cup shakes
Curved cracks
Seperates partly one
annual ring from other

233. Shake
Cup shake
Ring shake
Heart shake
Radial shake
Star shake
10. Shakes
When cup shakes cover entire annual rings
b) Ring shakes

234. 10. Shakes
Cracks formed at centre of cross-section
c) Heart shakes
Extends from pith to sapwood in
direction of medullary rays.
Due to maturity, inside starts shrinking
Divides tree into two or four parts

235. 10. Shakes
Cracks from bark towards sapwood.
d) Star shakes
Cracks upto sap only
Not reach heartwood or pith
Can remove outer area and use
Due to extreme heat or frost

236. 10. Shakes
Similar to star shakes
d) Radial shakes
Outer surface easily dries
Shrinks from outer to inner
But they are fine, irregular and numerous
Extends from bark towards center

237. 11. Twisted fibre
Also known as wandering hearts
Due to twisting of young trees by fast blowing wind
While sawing, it cuts fibers everywhere. Means it cannot
used by cutting. But can use as a single wood.

238. 12. Upset
Also known as rupture
Wood fibers injured by compression
Due to improper felling of trees
13. Water stain
Wood sometimes discolours when it
comes in contact with water
14. Wind cracks
If wood exposed to atmospheric agencies,
its exterior surface shrinks  cracks

239. 4. Defects due to insects
3. Termites
White ants
1. Beetles
Creates holes in wood  for food fine flour like powder
2. Marine borers
Salty waters  make holes in timber for shelter

240. 5. Defects due to seasoning
1. Check
Crack which seperates fibers of wood
Does not extend from one end to other

241. 2. Split
When a crack extends from one end to other

242. 3. Cup
Curvature formed in transverse direction
4. Bow
Curvature formed in direction of length of timber

243. 5. Twist
When a piece of timber get spirally distorted along
its length
6. Warp
When a piece of timber has twisted out of shape

244. 1. Check
2. Split
3. Cup
4. Bow
5. Twist
6. Warp
7. Collapse
8. Case hardening
9. Radial shake
10.Honey combing
7. Collapse
Due to uneven shrinkage, wood sometimes
flattens during drying.
8. Case hardening
Exposed surface of timber dries rapidly
Under Compression
Interior surface not completely dried
Under tension

245. 9. Radial shake
10. Honey combing
Due to stresses developed during drying, various
radial and circular cracks develop in the interior
portion of timber.

246. Seasoning of timber
Newly felled tree contains > 50 % water in form of sap
To use timber for engineering purposes, water should be
removed. (Timber should be dried)
Process of drying of timber to remove water is known as
seasoning.
Water is in the form of sap and moisture

247. Allows timber to burn rapidly, if used as fuel
To improve strength, hardness, stiffness, and
electrical resistance properties
To reduce tendency of timber to crack, shrink and warp.
To make the timber safe from attacks of insects and fungus.
To make the timber fit for uses for engineering purposes
Objects of Seasoning
Improves workability of timber
Reduces much of useless weight of timber

248. Methods of seasoning
Natural Seasoning Artificial Seasoning
When seasoning of timber
is carried out by natural air
or water.

249. Natural Seasoning
1. Water seasoning 2. Air seasoning
Timber is immersed in water
flow which helps to remove
the sap present in the timber
Allow timber to dry for
2 to 4 weeks
Arrange timber logs in layers
in a shed.
Air is circulated freely
between logs  moisture
reduces
Slow process, but we get
well seasoned timber

250. Artificial Seasoning
1. Boiling
Timber allowed to
dry after boiling for
3 to 4 hours
2. Chemical
Timber stored in
salt solution. Salt
absorb water.
3. Kiln
Timber stored in
salt solution. Salt
absorb water.
4. Electrical
timber subjected
to high frequency
AC currents

251. Carried out to increase the life of timber
Preservation of timber
Preserve timber from decaying
To increase durability, to get rid of insects and fungi, etc.
Application of chemical substance on timber surface
Presevatives makes timber ‘poisonous’ for insects and fungi
without affecting the structural properties of timber.

252. Methods of Timber Preservation
Brushing
Spraying
Injecting under pressure
Dipping and stepping
Charring
Hot and cold open tank treatment

253. Types of preservatives for timber
Coal tar – heat and apply using brush
ASCU – powder dissolved in water and apply by spraying
Chemical salts – CuSO4, ZnCl
Oil paints
Solignum paints – applied using brush
Creosote oil

254. Wood products
Industrial timber
– timber prepared scientifically in a factory
– examples are :
Veneer
Plywood
Fibreboard
Impreg timber
Compreg timber

255. 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

256. 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

257. 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

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

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

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

261. Impreg and compreg timber

262. 4. Impreg timber
Timber partly/fully covered with resins
Eg: Phenol formaldehyde
Veneers immersed in resins and heated
Trade names: Sunmica, formica, Sungloss
Not affected by moisture, weather, acids, etc
Low contraction and expansion
Glazing appearence

263. 5. Compreg timber
Same as impreg timber, but cured under pressure
Heat + Pressure
More strength and durability – good quality

264. Metals
Ferrous
metals
Non-ferrous
metals
1. Wrought iron
2. Cast iron
3. Mild steel
4. Special steels
a. High carbon steel
b. High tensile steel
c. Stainless steel
1. Aluminum
2. Copper
3. Lead
4. Zinc
5. Titanium
6. Cobalt
7. Nickel

265. Iron ores
Haematite
Limonite
Magnetite
Iron pyrites
Siderite
- Red oxide of iron |65-70 % iron
- Brown haematite | 60 % iron
- Black oxide of iron | 73 % iron (Richest)
- Sulphide of iron |45-47 % iron
- Carbonate of iron | Spathic iron | 40%

266. Crude impure iron extracted from iron ores
Parent metal of cast iron, wrought iron & steel
5 – 6 % Carbon content
Pig iron
Manufactured in blast furnace

267. Cannot magnetized
Cannot welded or rivetted
Does not rust
Difficult to bend
Hard and brittle
Neither ductile nor malleable
High compressive strength
Properties of pig iron

268. Pig iron
Cast iron Wrought iron Steel
 2 – 4 % carbon content
 Made in cupola furnace
 Cannot magnetized
 Good compressive
strength
 Will not rust easily
 Not ductile and malleable
 Uses: water pipes, sewers,
gates, lamp posts,castings,
compression members, rail
chairs, carriage wheels
Re-melting with
coke and lime
 Almost pure iron
 Less than 0.15 % C
 Reverberatory furnace
 Good tensile strength
Temporary magnetization
possible
Ductile, Malleable, fibrous
Fuses with difficulty (1500oC)
 Uses: Rivets, chains, nuts
and bolts, railway couplings,
handrails
 C = 0.25 – 1.5 %
 Bessemer process
 Permanent magnets
 Mechanical treatments
possible: forging,
drawing, pressing, rolling
 Malleable and ductile
 Types and uses:

270. Good conductor of heat and electricity
Highly resistant to corrosion
High temperature resistant
Light weight and takes more load
Specific gravity = 2.7
Possess great toughness and tensile strength
Ore: Bauxite (Al2O3.2H2O)
1. Aluminum
It readily dissolves in Hydrochloric acid

271. Utensils
Corrugated roofing sheets
Structural members
Electric wires
Window frames
For making parts of aeroplane
Uses of Aluminum
Possess great toughness and tensile strength
It readily dissolves in Hydrochloric acid

272. Cannot welded
It has a peculiar red colour
Ores:
Cuprite
Copper glance
Copper pyrites
Malachite
Azarite
2. Copper
Good conductor of heat and electricity

273. Specific gravity = 8.90
Malleable, ductile and soft
Not attacked by water at any temperature,
But attacked by steam at white heat.
Household utensils
Electroplating
Wires and electric cables
Uses of Copper

274. Specific gravity = 11.36
It can be cut with knife
It is lustrous metal with bluish grey colour
It is soft
Ore: Galena
3. Lead
Uses: Shot puts, bullets, base in paints,
storage cells

275. Not occur in free state in nature
It is a bluish white metal
It is not affected by dry air and water
It is brittle at ordinary temperature
Ore: Zincite, Franklinite, Calamine, Zinc Blende
4. Zinc
Uses: Paint, electric cells, Galvanising

276. Similar strength as steel & weight nearly half of steel
Have high melting point
Good corrosion resistance
Not found in free state
Stronger than aluminum
5. Titanium
Uses: Aerospace, marine, chemical and
biomedical applicatios – turbine blades, bone
screws, dental fixtures, surgical instruments