basic property of Building Material and it's explanation

basic properties and understanding of building materials

1. Chapter-1: introduction
Building Materials

2. overview
●Building materials are basic
requirement of construction
●Necessary to know the various types
of building materials
●It affects the usefulness, economy
and durability of structure
To understand better, it
is required to know the
properties of materials
such as…
●Physical properties
●Chemical properties
●Mechanical properties

3. Physical properties
1.Density
Mass of unit volume of material
It means mass (in kg, gm, lb) of
unit volume (in m3, cm3, ft3)

4. Weight of unit volume of
homogeneous material
In simple words, ratio of
material density with
water density
Physical properties
2. Specific Gravity

5. Mass of unit volume
including voids
Almost same as first
property
Physical properties
3. Bulk density

6. Ratio of volume of pores
and volume of total
sample
Physical properties
4. porosity

7. Ability of the material to
absorb water
Physical properties
5. Water absorption

8. Capacity of material to
allow water to pass
through it.
Means at constant pressure
the amount of water
passing from unit area.
Physical properties
6. Permeability

9. Ability of the
material to absorb
water from the
atmosphere water
vapour
Physical properties
7. Hygroscopicity
Hygroscopic Nuclei

10. Ability of material
to withstand high
temperature without
deforming or losing
load bearing capacity
Physical properties
8. Fire resistance

11. Specific Heat
Take a unit mass and heat
it
The heat given for 1 degree
increase in temperature is
Specific Heat
Physical properties
9. Thermal properties
Thermal Resistivity
It is reciprocal of Thermal
conductivity
Thermal conductivity
If time, area, and thickness
is unit,
Temperature difference
between faces is 1 degree,
Then the heat transferred
is called Thermal
conductivity

12. Ability of resisting alternate
freezing and thawing, without
losing mechanical strength
considerably, when the material
is saturated with water.
Physical properties
10. Frost resistance

13. Resistance of material
against destruction by
natural agencies
Physical properties
11. Durability

14. Ability of the material
to resist the size/volume
changes.
Physical properties
12. Soundness 13. Acoustic property
Deals with origin,
transmission, absorption
and insulation of sound.

15. Material’s reaction with gases,
water, moisture, salinity,
sulphate, and other things

Chemical properties
which changes its composition,
physical state, color, properties
etc.

16. Mechanical
properties
Ability to resist various
loads safely without
deforming
Strength

17. Material deforms when
loaded.
If regains original shape
and size after load
removal that property is
called elasticity
Mechanical
properties
Elasticity

18. If material does not get
original shape and size
after load removal, that
property is called
plasticity.
Mechanical
properties
Plasticity

19. Sudden failing of material
without considerable
deformation
Mechanical
properties
Brittleness

20. Tendency to deform more
and more under sudden
loading without failure.
Mechanical
properties
Ductility

21. Resistance to abrasion,
wear, scratching
Mechanical
properties
Hardness

22. Resistance to wearing due
to contact movement
between surfaces
Mechanical
properties
Abrasion

23. Continuous slow deformation
over long term by constant
load
Mechanical
properties
Creep

24. If Loaded repeatedly
in reversed loading
condition, material
fails at very low
stress level is
called fatigue
Mechanical
properties
Fatigue
Ability to deform
without breaking
Tenacity

25. Ability to resist
impact
Mechanical
properties
Toughness

26. Quality
●Economical & have
required quality
●Not necessary to select
always a best material
Selection of appropriate materials
Strength
●It should just perform
safely
●Not necessary to take
strongest one
Availability
●Should be available
easily
●Avoid storage and huge
purchase
Durability
●Life should be equal to
structure
●Should be sufficiently
strong to resist forces

27. Workability
●Material should be
brought to shape and size
by with less effort and
skills
Selection of appropriate materials
Transportation
●Try to have locally
available material
●No breakage during
transportation
Climate
●Should suit the climatic
condition
Appearance
●Should have good view and
proper colour

28. Modern Technology:
Use of new material for economical purpose
Selection of appropriate materials
Economy :
Should cost lesser than other alternatives
Speed of construction:
Select to construct speedily and easily

29. Use of Material for various construction
StoneaggregatesLime
Bricks, walls, Floor finish, plaster, filling etc.Clay
Mortar, Foundation, Flooring, Walls, Plaster, White
Washing, etc.
Lime
Mortar, plaster, foundation, RCC works, floors, precast
unit, pipes, paints etc.
Cement
Foundations, walls, flooring, lintels, columns, slab etc.Stone
RCC works, mortar, concrete, foundation, flooring,
pavement, plastering etc.
Aggregate

30. Use of Material for various construction
StoneaggregatesLime
Furniture Components, truss components, beam
columns, form work etc .
Wood
Foundation, filling, RCC work, plaster, mortar, flooring etc.Sand
Building Components, pipes, reinforcements, truss
components, furniture components etc.
Steel
Door, window, ventilation, fittings, tank, pipes etc.Plastic
Door, window, fitting, furniture, pipes, tanks etc.Glass

31. Use of Material for various construction
StoneaggregatesLime Door, window, ventilation, pipes, wires, sections, fittings
etc .
Aluminium
Damp proofing, water proofing, roads, paints etc .Bitumen
Pipes, sheets, roofing partition, damp proofing
insulations etc .
Asbestos

32. Clay products
Arbaz H Khatuda

33. Clay
●Clay is formed by different elements but main constituents are kaolinite and
Silica. Kaolinite gives plasticity and silica reduces shrinkage.
●Clay is made by disintegration of rocks due to weathering and chemical
actions.
●By adding water it can be shaped in any form, and after burning in kiln,
chemical reaction of ingredients makes it hard.
●Bricks, tiles, stonewares, etc are the products of clay that are being used
widely in construction.

34. Classification of Clay Products
China Clay
stonewares
porcelain etc
Brick Clay:
●Bricks
●Tiles
●Earthen Wares
Fire Clay:
Fire bricks
●Acidic
●Basic
●neutral
Bentonite
Used as filler
material

35. Standard Requirements of Bricks
Determined By two types of tests : Field Testing and Lab Testing
Field Testing
●Testing for Shape and Size :
Standard brick size should be
19 cm X 09 cm X 09 cm for full brick
19 cm X 09 cm X 04 cm for half brick
Brick should have regular shape,
rectangular face, sharp corners and even
surfaces
●Colour :
Should have uniform bright copper colour.
Overburnt is dark red, under burnt is
yellowish.
●Texture :
Homogeneous, compact, free from voids,
cracks, flaws, lumps etc.
●Sound :
When two bricks are struck, they should
produce ringing sound and should not
break.
●Strength :
Should not break when dropped from 1 m
height.
●Other Tests :
Have less than 50% efflorescence.
no marks for nail scratching.
should have proper frog.

36. Manufacturing of Bricks
Selection of Clay: Brick Clay Should Contain following Ingredients,
●Alumina: 20-30% → gives plasticity → easy moulding → excess causes shrinkage,
warping, too hard bricks.
●Silica: 50-60% → combines with alumina and makes brick hard, strong, durable,
prevents shrinkage, warping and pressure provides uniform shape to bricks → excess makes
brick porous, brittle and problems in burning.
●Lime: about 5% in powder form → reduces shrinkage → fuses with silica, form
hard binding material → gives strength → excess causes melting and deformations →
nodules causes disintegration with moisture.
●Iron oxide:5% desirable → helps in fusing sand → makes brick red → excess causes
softness and deformation in burning → becomes dark → shortage causes yellowish color.
●Magnesia: small quantity makes it yellowish and reduces shrinkage → excess causes
decay of bricks.

37. Harmful ingredients for brick clay
●Lime :
Excess lime deforms the brick, nodules causes disintegration in presence of
moisture.
●Iron Pyrites:
Crystallizes and splits brick into pieces.
●Peebles :
Prevents proper mixing → makes brick non-homogeneous, weak, porous.
●Alkalies:
Acts as a flux → causes brick to fuse, warp, twist → hygroscopic hence causes
efflorescence.
●Organic Matter :
Makes brick porous.
Manufacturing of Bricks

38. 1.Excavation
Remove top layer of roughly 150 mm containing leaves,
roots, grass, vegetables, peebles etc
Excavate earth, break clods, remove peebles, lime, kankar,
roots vegetation etc.
Manufacturing of Bricks
2.Weathering
Sprinkle water over excavated soil spread it in form of heap.
Allow to weather for a month.
Turn at least twice during weathering.
3.Blending
Break the clods, add necessary ingredients.
Turn up and down for through mixing, add water if required.
4.Tempering
Add sufficient water to make soil homogeneous and plastic.
Knead under the feet by men or cattles.
Use pug mill for large scale manufacturing.

39. Pug Mill
●Top diameter slightly more than
bottom diameter.
●Height : usually 2 to 3 m.
●⅓ height is below in the ground.
●Vertical shaft pivoted in timber bottom.
●Horizontal arms with blades are
attached to shaft.
●Rotated by electric or diesel power.
●Clay and water is added from top, and
material is mixed.
●Mixture is taken out from opening at
bottom.

40. Moulding of Bricks
Hand moulding
●Metal mould has longer life.
●Dimension are kept 10% more to allow
for shrinkage during drying and burning.
●Multiple moulds are also prepared.
Ground Moulding
●Suitable on level Ground.
●sometimes plasters ground with
sprinkled sand.
●If mould is dipped in water before
moulding → slop moulded bricks.
●If fine sand or ash is sprinkled → bricks
will have sharp, straight edges → sand
moulded bricks.
● Prepared moulds placed on ground →
lump of tempered clay dashed in the
moulds → pressed to remove hollow voids
→ surplus is removed by wire frame or
sharp plate called strike → mould lifted,
brick left on ground → lower faces are
rough.

41. Moulding of Bricks
Table moulding
●Process similar to earlier types, all
material is placed on a large table and
the moulders stand near the table and
mould the bricks.
Machine Moulding
●Used for large quantity.
●Better quality bricks with economic cost.
●2 processes
1. Stiff mud process
2. Dry process
●In stiff mud process, less water is added
and forced from the dye to get shape.
●Comes out as continuous ribbon, cut by
knife or wire.
●In dry process, very little water added,
then filled in mould and pressed by
plunger.
●Drying period can be reduced or avoided.

42. Natural Drying
→ Bricks turned on edges and left for 2-3 days to
become hard for handling.
→ Should be protected from sun rays and severe wind.
→ Then staked in such way that free air circulates in
between by keeping gapes in staking arrangement.
→ Protected from sun and rain. Left for roughly one week
depending on weather.
Drying of Bricks
Artificial Drying
Can be of 2 types (1) Hot Floor Dryer (2) Tunnel Dryer
→ Hot floor dryers are heated by hot flue gases or furnace
placed at one end of dryer.
→ Tunnel dryers are heated by hot air from kilns.
→ Dryers Can be continuous to load from one end and
unload from other or batching type.
→ Tunnel dryers are economical.
→ Artificial dryers take less time and used for large scale
production, can be continued in rainy season.
Necessity:→ Bricks gets strong for handling and stacking.→ Reduces cracks and distortion during burning.
→ Saves fuel while burning.
It can be (a) Natural Drying or (b) Artificial Drying

43. Burning of
Bricks
burnt in Clamp or kiln.
Clamp→ Temporary structure,
used for small scale local demand.
Kiln→ Permanent Structure,
suitable for large scale production.
Clamp:
●Trapezoidal shape in plan.
●Shorter side kept slightly in ground.
●Slight slope of roughly 15° is given.
●Local fuel such as cow dung, wood, leaves, placed in layer of
70-80 cm.
●Bricks are placed above in 4-5 layers with gapes for air.
●Repeated layers of fuel and bricks are placed upto 3-4 m
height.
●Lower portion is ignited, thickness of fuel is reduced in upper
layer.outside is plastered with clay and top is filled with clay.
●Burning is continued for one month and then cooling for one
month.
Advantage of clamp: → local fuel
is used → economical burning →
minimum supervision required.
Disadvantages of clamp: → non
uniform burning, resulting in under
burnt, over burnt bricks → slow
process → not possible to control
fire → final shape is not uniform

44. Kiln
There are two types:
1) Intermittent kilns 2) Continuous kilns
Intermittent kiln: bricks are supplied in it at regular time
interval.
●Rectangular structure with thick walls.
●Opening for fuels provided with doors to control firing.
●Doors in short wall for brick loading-unloading.
●Laid in 2-3 rows upto 8-10 layers in height parallel to short
wall.
●2 brick wide space left in between for fuel.
●Top of fuel space to be covered by projecting bricks from
upper layer of brick rows.
●After loading of bricks, top is covered by earth to prevent
loss of heat.

45. Kiln
Intermittent kilns
Process:
Firing : slow firing for first 2-3 days to drive out the moisture, then
strong firing by raising doors for flues.
Cooling : slow cooling by closing doors for flues upto 8 days, slow
cooling prevents cracking of bricks.
Unloading : started by removing top earth layer. → quality is better
than clamp → some bricks remains unburnt while some at bottom are
over burnt → this can be resolved by down draught intermittent kilns
where hot gases are forced to move downwards for heating bricks
by chimney draughts. → due to close control on firing, evenly burnt
bricks are obtained.

46. Kiln
Continuous kilns: for non stop supply of bricks
3
BurningPre-heating
21
Loading
Air Circulation Path
5
Unloading
4
Cooling
Air EntryEscape of Air

47. Continuous Kiln
●Air is entered from the unloading point, which
cools the bricks that comes out.
●Then enters in the kiln to help in burning.
●Then heated air goes to entry portion which
pre heats the bricks.
●Lastly, exits from the loading point.
●Direction of air circulation is reversed to
direction of production process.
There are various types of continuous kilns but
most popular are bull trench, hoffman and tunnel
kilns.

48. Bull Trench Kiln
●Can be full or partially in
ground.
●Oval or rectangular shape.
●Divided by dampers.
●Bricks loaded with space
for flues.
●Holes are provided at top
for inserting flues.
●Movable chimneys are
provided on top where
raw bricks are loaded.
●Fire holes are closed when
burning is ended, each
section takes one day to
burn bricks.
●Chimney is shifted to next
section when burning of
other section is started.
Favorable points:
●Good quality of bricks
●Non-stop supply
●Saving of drying space
●Saving of time
●Economy in fuel consumption.
Against all above, high initial cost
and closed Supervision is
necessary.

49. Hoffman’s Kiln
→ Circular shape.
→ It has central chimney, 12
compartment doors and dampers.
→ Compartments are connected to
chimney.
→ compartments are connected to
chimney by dampers and have
holes for fuels in powdered form.
→ cool air enters at 1 where burnt
bricks are unloaded.
→ passes through 12, 11, 10, 9, 8
where burnt bricks are being
cooled.
→ bricks are burnt in 6 and 7
→ heated air preheats bricks at 3,
4, 5
→ Raw bricks are laid in 2, heated
air is passed upward through
chimney.
→ Burning is shifted to 4,5 in next
phase. Process will be continued.
Favorable point:
●Low fuel consumption
●Saving of time
●Work continued in rainy
season
●Good quality of bricks
●Arrangement in limited area
●No extra space needed for
drying
Against all above, skilled
supervision and high initial cost
may be overlooked.

50. Tunnel kiln
●Continuous in form of tunnel , it
can be straight, circular, or oval.
●Rail tracks are provided for
trolleys
●Bricks are placed in trolley
●Bricks get dried, preheated
before burning
●Bricks are burnt and forwarded
for cooling
●Cooled bricks are unloaded

51. COMPARISON:
CLAMP
&
KILN
Points Clamp Kiln
Quality Ordinary Good
Production in numbers 25000-100000 per operation More than 200000 in a day
Time of cycle 3-6 months About 14 days
Structure Temporary Permanent
Suitability Limited production Large scale production
Production continuity Discontinuous Continuous
Fuel Any type of local fuel Selected coal
Optimum utilization of fuel Not possible Gases used for preheating
Labour Ordinary labourers required Trained person required
Cost Low High
Control of burning No control Possible
Wastage of bricks 35% 10%
Operations One at a time All process at a time

52. Flow diagram of brick manufacturing
Drying
Natural or artificial drying
Burning
Burning in clamp / intermittent
kiln / continuous kiln and storing
Preparation of clay
1.Removal of top layer of soil
2.Weathering for one month
3.blending /adding
ingredients
4.Tempering-kneading of clay
Moulding
Table / Machine / Ground moulding
with/without frog

53. Types of brick
Queen closer King closer Squint brick Splay/cant brick
Plinth stretcher Coping brick Cornice brick Bull nose brick

54. Types of brick
Double bullnose brick Gutter brick Perforated brick
Hollow brick Chequered brick Voussoir brick

55. Other types of bricks
Refractory bricks:
●can resist high temperature and
thermal shocks without yielding.
●Prepared from refractory materials
suitable for furnaces operating at
high temperature.
● There are three types
○Acidic bricks
○Basic bricks
○Neutral bricks
Acidic bricks: fire bricks & silica bricks
Fire bricks:
●prepared from fire clay consisting molten
silica, alumina and little quantity of fluxes.
●No oxides of calcium, magnesium or iron
so no melting at high temperature.
●Classified as high duty, medium duty and
low duty.
●Suitable for lining of steel furnaces,
reverberatory furnaces and glass making
furnaces.
Silica bricks: 95% silica + 2% CaO, little fire clay
added → High pressure moulding and high
temperature burning → compressive strength > 15
N/sqmm → temperature resistance upto 2000°C
→ joints are bigger due to more expansion →
used in steel industry and bessemer converter.

56. Basic bricks:
Manufactured from magnesite, dolomite,
and bauxite and accordingly knowns as
1.Magnesite bricks
2.Dolomite bricks
3.Bauxite bricks
Magnesite bricks: oxides of magnesium and
calcium with little silica → Magnesium chloride
added to improve plasticity → used for lining in
bessemer converter, open hearth furnaces, blast
furnaces and in metallurgy.
Dolomite bricks: prepared from calcined
dolomite, carbonate of magnesia and lime →
contracts at high temperature.
Bauxite Bricks: contains more than 50 % alumina
and iron oxides, little silica and fire clay → more
shrinkage at high temperature, hence not much
popular.
Neutral Bricks:
Types of neutral bricks are: chrome brick,
chrome magnesite brick, forsterite brick,spinel
bricks.
Chrome bricks: contains oxides of chrome,
magnesium, aluminium and silicon, chrome oxide
is the main ingredient.they resist corrosion but
not satisfactory as refractory bricks.
Chrome magnesite bricks: main ingredients are
chrome ore and magnesite. These bricks are
strong.
Forsterite bricks: forsterite is chief ingredient.
They have good strength and low shrinkage.
Spinel bricks: consists magnesia and alumina,
prepared in electric furnace.
Neutral bricks are used in furnace where
reaction may be acidic or basic.

57. Fly Ash bricks:
●Fly Ash is residue of coal burning,
available at thermal power plant,
becomes cementing material with
combined with lime.
●Lime, sand and fly ash is mixed as 1:2:12.
●Paste is obtained by adding suitable
amount of water.
●Hydraulic press is used in preparing
bricks.
●Curing is done in steam chamber with
required temperature and pressure.
●Better in many aspect compared to
regular bricks.
●Good shape and size with 10%
economical.
Sand lime bricks:
●Known as calcium silicate bricks.
●Prepared by 85% sand, 10% lime and
little clay.
●Pigments are added for desired
colors.
●Manufactured using rotary press,
autoclave, and high temperature with
humidity.
●Hard, dense, uniform, strong, smooth
and free from efflorescence.
●Costly hence not suitable for
foundation, furnace.
●Weak in abrasion, most suitable for
face work and decoration only.

58. Acid Resistant brick:
Prepared from clay and low percentage of lime, sand and felspar. They are vitrified in
ceramic kiln.
Use: chemical plants, sewers conveying effluent and constructions likely to come in
contact with acids.
Burnt clay facing bricks:
These bricks possess more compressive strength. They absorb less water. Have good
shape, size, color. Minimum warping and efflorescence.
Use: for facing work in area having corrosive atmosphere.
Over burnt bricks:
Strong compact structure but irregular shape and dark non uniform color, suitable
pavement and aggregates for floors, roads etc.

59. Laboratory
testing of bricks
Grades of bricks
●Ordinary bricks:
crushing strength ≮ 3.5 N/mm^2
●Class A bricks:
Crushing strength 7-14 N/mm^2
Length tolerance- ± 30 cm
Total length of 20 pc - 350-410 cm
Width tolerance- ± 20 cm
Total width of 20 pc - 165-195 cm
●Class AA bricks:
Crushing strength > 14 N/mm^2
Length tolerance- ± 12 cm
Total length of 20 pc - 368-392 cm
Width tolerance- ± 6 cm
Total width of 20 pc - 174-186 cm
Following tests are common for
bricks
●Crushing strength
●Efflorescence
●Water absorption
●Soundness

60. Bricks used in construction
First class brick: burnt in kiln - table moulded - standard shape - sharp edges
smooth surface - good quality. Use: face work, buildings, dams, roads, bridges etc.
Second class brick: ground moulding - kiln burning - slight rough surface - slight
irregular shape - edges straight but not sharp and uniform - hair cracks
Use: where walls are plastered, more mortar required
Third class brick: ground moulding - clamp burning - rough surface - not hard- edges
irregular and distorted - dull sound when struck
Use: unimportant and temporary works, not suitable for wet climate.
Fourth class brick: over burnt bricks with irregular shape - dark non-uniform color -
strong but non-uniform
Use: road metal, aggregate for foundation.

61. Classification by grade
Grade-A: compressive strength > 10.5 N/mm^2, water absorption <20%,
uniform color - well burnt - table moulded - sharp edges - hard - suitable
for external works.
Grade-B: compressive strength > 7 N/mm^2, water absorption <22%, table
moulded - useful for ordinary work
Grade-C: compressive strength > 3.5 N/mm^2, water absorption <25%,
soft, can be used for unimportant work, can be used below plinth.
Grade-D: over burnt-under burnt, soft, yellowish, can be used as
aggregates.

62. Other clay
products
1.Tiles
2.Earthenwares
3.Stonewares
4.Glazing
Tiles:
●Floor tiles
●Roof tiles
○Pot tiles
○Pan tiles
○Flat tiles
○Mangalore tiles
○Allahabad tiles
○Corrugated tiles
○Guna tiles
○Encaustic tiles

63. Earthenware
●Prepared from clay, sand and
crushed pottery.
●Soft and porous but can be made
hard and impervious on glazing.
●Terracotta and porcelain are
earthenwares.
Porcelain:
Hard, brittle, non-porous, used for
electric insulation, sanitary wares,
storage vessels etc.
Made by
1.Dry Process: ingredients are
mixed and pressed in hydraulic
press and burnt in kiln
2.Wet Process: mixed by water
forming paste, moulded, dried,
glazed and burnt in kiln.
Used for electrical goods
Terracotta:
Porous: sawdust added in making,
fire and sound proof, can be chiseled,
sawn or nailed.
Polished: superior quality, not
affected by weather, prepared in kiln
then glazed and again burnt in kiln.
Used for decoration and ornaments.

64. Stoneware
Protective treatment, it can be transparent, coloured, opaque.
Following are the types
●Transparent glazing
○Salt glazing
○Lead glazing
●Opaque glazing
●Refractory clay is used
●Durable, impervious, strong, resists corrosion
●Suitable for sanitary wares, sewer pipes, glazed tiles, WC pan, wash
basin, sink, bathtub, etc
Glazing