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LECTURE NOTE
on
CIVIL ENGINEERING MATERIALS & CONSTRUCTION
COURSE CODE: BCE 203

SYLLABUS
Module Chapter
Number Number
1
1
2
3

Title

2

Arches
Cavity Wall
Stairs

Brick
Cement
Concrete
Total

4
5
6

Total
3

7
8
9

Fire Resistive Construction
Plastering
Damp prevention
Total

4

10
11
12
13
14
15
16

Types of doors and windows
Painting and decoration
Glazing
Repair of Building
Stone
Timber
Foundation
Total
Total lecture hours

Lecture hours
(3-1-0)
3
4
3
10
3
2
3
8
2
2
2
6
3
2
2
2
1
4
2
16
40

Text books
1
...
P
...
P
...

Reference books
1 A Text Book of Building Materials, C
...
Kulkarrni
2 Building Materials, P
...
Varghese, PHI, Pvt
...

3 Building Construction, P
...
Varghese, PHI, Pvt
...


1
...
Bricks are prepared by moulding
clay in rectangular blocks of uniform size and then drying and burning these blocks
...

o
o
o
o
o

Silica
Alumina
Lime
Iron oxide
Magnesia

Silica
o
o
o
o

Brick earth should contain about 50 to % of silica
...

It also affects the durability of bricks
...


Alumina
o
o
o

Good brick earth should contain about 20% to 30% of alumina
...

If present in excess, then the raw brick shrink and warp during drying
...

It prevents shrinkage of bricks on drying
...

Excess of lime causes the brick to melt and brick looses its shape
...

It gives red colour to the bricks
...

It gives strength and hardness
...

If the quantity of iron oxide is comparatively less, the brick becomes yellowish in

colour
...

It is responsible for reducing shrinkage
Excess of magnesia leads to the decay of bricks
...

Lime
o
o

A small quantity of lime is required in brick earth
...

If lime is present in the form of lumps, then it is converted into quick lime after
burning
...


Iron pyrites
o

The presence of iron pyrites in brick earth causes the brick to get crystallized and
disintegrated during burning, because of the oxidation of the iron pyrits
...


Alkalis
o

o

These are exist in the brick earth in the form of soda and potash
...
Because of this,
bricks are melted and they loose their shape
...
With the passage of time, the moisture gets evaporated
leaving grey or white deposits on the wall surface (known asefflorescence)
...


Pebbles
o
o

Pebbles in brick earth create problem during mixing operation of earth
...


Vegetation and Organic Matter
o

The presence of vegetation and organic matter in brick earth assists in burning
...
This is due to the fact
that the gasses will be evolved during the burning of the carbonaceous matter and it
will result in the formation of small pores
...

•
•
•
•

Preparation of clay
Moulding
Drying
Burning

Each of the above operation of the manufacturing bricks will now be studied at length
...

• Unsoiling
• Digging
• Cleaning
• Weathering
• Blending
• Tempering
Unsoiling: The top layer of the soil, about 200mm in depth, is taken out and thrown away
...

Digging: The clay is then dug out from the ground
...
The height of heaps of clay is about 600mm to 1200mm
...
If these particles are in excess, the clay is to be washed and
screened
...


3

* Under revision

Weathering: The clay is then exposed to atmosphere for softening and mellowing
...

Blending: The clay is made loose and any ingredient to be added to it , is spread out at its top
...
It is carried out by taking a small
amount of clay every time and turning it up and down in vertical direction
...

Tempering: In the process of tempering, the clay is brought to a proper degree of hardness
and it is made fit for the next operation of moulding
...
The tempering should be done exhaustively to obtain homogeneous mass of
clay of uniform character
...
A typical pug mill capable of tempering sufficient earth for a daily output of
about 15000 to20000 bricks
...
It is fixed on a timber base
which is made by fixing two wooden planks at right angle to each other
...
The diameter of pug mill at bottom is
about 800mm and that at top is about 1 m
...
A vertical shaft with horizontal arms is provided at center of iron tub
...
The long arms are fixed at vertical shaft
to attach a pair of bullocks
...
The height of
pug mill is about 2m
...
In the beginning, the hole for pugged
clay is closed and clay with water is placed in pug mill from the top
...

The rotation of vertical shaft can also be achieved by using steam, diesel or electrical
power
...
e
...
The pug mill is then kept moving and feeding of clay from top
and taking out of pugged clay from bottom are done simultaneously
...


4

* Under revision

Fig of a Pug mill
Moulding:
The clay which is prepared as above is then sent for the text operation of moulding
...


Hand Moulding

ii
...
e
...
It is adopted where
manpower is cheap and is readily available for the manufacturing process of bricks ona small
scale
...
They may be of
wood or steel
...
The longer sides are kept
slightly projecting to serve as handles
...
It is prepared from the combination of
steel plate and channel
...
Thethickness of
steel mould is 6mm
...
The steel moulds
are more durable than wooden one and turn out bricks of uniform size
...
Hence the mouldsare therefore made larger than burnt bricks (812%)
...
The
mould is dipped in water and placed over the ground
...
The clay is pressed in the mould in such a way that it fills all the
corners of mould
...
A strike
is a piece of wood or metal with a sharp edge
...
The
mould is then lifted up and raw brick ids left on the ground
...
The process is repeated till
the ground is covered with raw bricks
...
A frog is mark of depth about 10mm to
20mm which is placed on raw brick during moulding
...

1
...
In brick work, the bricks are laid with frog uppermost
...

The ground moulded bricks of better quality and with frogs on their surface are made by
using a pair of pallet boards and a wooden block
...
The block
is bigger than the mould and it has projection of about 6mm height on its surface
...
The design of
impression or frog is made on this block
...

The mould is placed to fit in the projection of wooden block and clay is then dashed inside
the mould
...
The
mould is taken out and placed over the raw brick and it is conveyed to the drying sheds
...
As the bricks are laid on edge, they occupyless space and they dry
quicker and better
...
But in this case, the mould
stands near a table size 2m x 1m
...

ii) However the efficiency of the moulder gradually decreases because of standing at
some place for a longer duration
...

Machine Moulding:
This type of moulding is carried out by two processes:
i)
ii)

Plastic clay machine
Dry clay machine

Plastic Clay Moulding
i) Such machine consists of a rectangular opening having length and width is equal to an
ordinary bricks
...

ii) These are cut into strips by the wire fixed at the frame
...
So it is also called as
WIRE CUT BRICKS
...
A small quantity of
water is then added to form a stiff plastic paste
...

They do not require the process of drying
...
Hence the moulded bricks are
dried before they are taken for the next operation of burning
...
The bricks are laid along and across the stock in alternate layers
...
The bricks are allowed to dry until the bricks are become leather hard of
moisture content about 2%
...
All the water is removed at the temperature of 650 degrees but they are burnt at
an temperature of about 1100 degrees because the fusing of sand and lime takes place at this
temperature and chemical bonding takes between these materials after the temperature is
cooled down resulting in the hard and dense mass
...
Bricks can be burnt using the following methods:
(a) Clamp Burning
(b) Kiln Burning
Clamp Burning:
Clamp is a temporary structure generally constructed over the ground with a height of about 4
to 6 m
...
This is generally trapezoidal in plan whose shorter edge among the parallel
sides is below the ground and then the surface raising constantly at about 15 degrees to reach
the other parallel edge over the ground
...
First layer of fuel is laid as the bottom most layer
with the coal, wood and other locally available material like cow dung and husk
...
The
thickness of the fuel layer goes on with the height of the clamp
...
Fire is ignited at the bottom, once fire is started it is kept under fire by
itself for one or two months and same time period is needed for the cooling of the bricks
...

Bricks at the bottom are over-burnt while at the top are under-burnt
...

Bricks loose their shape, and reason may be their descending downward once the fuel
layer is burnt
...

This method cannotemploy for the manufacturing of large number of bricks and it is
costly in terms of fuel because large amount of heat is wasted
...

It cannot be employed in monsoon season
...
Generally coal and other locally available
materials like wood, cow dung etc can be used as fuel
...

Continuous Kilns
...
Various major processes which takes place in the kilns
are:Loading, unloading, Cooling, and Burning of bricks
...
In up draught kilns the hot gases are released after they
rise up to chimney entrance
...
They are used when the bricks are demanded
in larger scale and in short time
...
There are two well-known continuous kilns:
Bull's Trench Kiln:Bull's trench kiln consists of a rectangular, circular or oval plan shape
...
This Trench is divided generally in 12 chambers so
that 2 numbers of cycles of brick burning can take place at the same time for the larger
production of the bricks
...
The structure is
under-ground so the heat is conserved to a large extent so it is more efficient
...

Such kilns are generally constructed to have a manufacturing capacity of about 20,000 bricks
per day
...

Hoffman's Kiln:The main difference between the Bull's trench kiln and the Hoffman kilns
are:
1
...

2
...

Hoffman's kiln is generally circular in plan, and is constructed over the ground
...


9

* Under revision

Classification of Bricks as per common practice:
Bricks, which are used in construction works, are burnt bricks
...

1
...

3
...


First class bricks
Second class bricks
Third class bricks
Fourth class bricks

First Class Bricks:
These bricks are table moulded and of standard shape and they are burnt in kilns
...
They comply with all the
qualities of good bricks
...

Second Class Bricks:
These bricks are ground moulded and they are burnt in kilns
...
These bricks may have hair cracks and
their edges may not be sharp and uniform
...

Third Class Bricks:
These bricks are ground moulded and they are burnt in clamps
...
These bricks give dull sound
when struck together
...

Fourth Class Bricks:
These are over burnt bricks with irregular shape and dark colour
...


Classification of Bricks as per constituent materials
There are various types of bricks used in masonry
...
Then these bricks are dried and
fired in a kiln
...
When these bricks are used in walls, they require plastering or rendering
...
The mix is then moulded under pressure forming the brick
...
Their shape is uniform and presents a smoother finish that doesn’t
require plastering
...


Engineering Bricks
Engineering bricks are bricks manufactured at extremely high temperatures, forming a dense
and strong brick, allowing the brick to limit strength and water absorption
...


Concrete Bricks
Concrete bricks are made from solid concrete
...
These bricks can be manufactured to
provide different colours as pigmented during its production
...
Some
studies have shown that these bricks tend to fail poor produce pop-outs, when bricks come
into contact with moisture and water, causing the bricks to expand
...
In these tests some are
performed in laboratory and the rest are on field
...
It is
also called crushing strength of brick
...
In this test a brick specimen is put on crushing machine and
applied pressure till it breaks
...
All five brick specimens are tested one by one and average result is taken as brick’s
compressive/crushing strength
...
After 24 hours of immersion those are taken out from
water and wipe out with cloth
...
The difference
between weights is the water absorbed by brick
...
The less water absorbed by brick the greater its quality
...

Efflorescence test: The presence of alkalies in bricks is harmful and they form a grey or
white layer on brick surface by absorbing moisture
...
In this test a brick is immersed in fresh water for 24 hours and
then it’s taken out from water and allowed to dry in shade
...
If the whitish layer visible about 10% of
brick surface then the presence of alkalis is in acceptable range
...
If the alkalies’ presence is over 50% then the brick is severely
affected by alkalies
...
If that doesn’t
left any impression on brick then that is good quality brick
...
Bricks are closely viewed to check if its edges are sharp and straight

12

* Under revision

and uniform in shape
...

Soundness test: In this test two bricks are held by both hands and struck with one another
...

Structure test: In this test a brick is broken or a broken brick is collected and closely
observed
...


13

* Under revision

2
...

Cements used in construction can be characterized as being either hydraulic or non-hydraulic,
depending upon the ability of the cement to be used in the presence of water
...
It can be attacked by some aggressive chemicals after
setting
...
The chemical reaction results in hydrates
that are not very water-soluble and so are quite durable in water and safe from chemical
attack
...
g
...


Use
•

Cement mortar for Masonry work, plaster and pointing etc
...

•

Construction

for

important

engineering

structures

such

asbridge,culverts,dams,tunnels,light house,clocks,etc
...


•

Making joint for joints,pipes,etc
...


•

Preparation of foundation, water tight floors, footpaths, etc
...
A list of some commonly
used cement is described in this section:

14

* Under revision

Ordinary Portland cement
Ordinary Portland cement is the most common type of cement in general use around the
world
...
The resulting hard substance, called 'clinker', is then ground with a small amount of
gypsum into a powder to make 'Ordinary Portland Cement'(often referred to as OPC)
...
The
most common use for Portland cement is in the production of concrete
...
As a
construction material, concrete can be cast in almost any shape desired, and once hardened,
can become a structural (load bearing) element
...

•
•
•
•
•
•
•
•
•

This type of cement use in construction when there is no exposure to sulphates in the
soil or ground water
...
e
...
66 to 1
...

Free lime-cause the Cement to be unsound
...
66
...
5%
...
5% when C 3 A < 7% and not more than 3% when
C 3 A >7%
...
)
Fineness -not less than 2250 cm2/g
...

Its 3 days strength is same as 7 days strength of ordinary Portland cement
...
While in
low heat cement it is about 50cal/gm of cement
...
P
...

Reduce and delay the heat of hydration
...
1370 : 1974 ) limit the
heat of hydration of this cement
...
5% and minimum fineness by 2500 cm'/g
...

Sulphate forms the sulpha-aluminates which have expensive properties and so causes
disintegration of concrete
...

Its strength in early days is less and hence it required longer curing period
...


Pozzolanic cement
•
•
•
•
•

As per Indian standard, the proportions of Pozzolana may be 10 to 25 % by weight
...
2
...

This Cement has higher resistance to chemical agencies and to sea water because of
absence of lime
...

It possesses less resistance to the erosion and weathering action
...


White Portland cement
•

•

•

Grey colour of O
...
cement is due to presence of Iron Oxide
...
Sodium Alumina Ferrite (Crinoline) NavAlF6 is added to act
as flux in the absence of Iron-Oxide
...

White Cement are used in Swimming pools, for painting garden furniture, moulding
sculptures and statues etc
...

The amount of colouring material may vary from 5 to 10 percent
...

The iron Oxide in different proportions gives brown, red or yellow colour
...


Expansive cement

16

* Under revision

•
•

This type of cement is produced by adding an expanding medium like
sulphoaluminate and a stabilising agent to the ordinary cement
...


High alumina cement
•
•

This cement is produced by grilling clinkers formed by calcining bauxite and
lime
...

If evolves great heat during setting
...


Composition of Cement clinker
The various constituents combine in burning and form cement clinker
...
They are known as Bogue compounds after the name of Bogue who identified them
...

Tricalcium silicate
It is supposed to be the best cementing material and is well burnt cement
...
It renders the clinker easier to grind,increases
resistance to freezing and thawing, hydrates rapidly generating high heat and developsan
early hardness and strength
...
The hydrolysis of C 3 S
is mainly responsible for 7 day strength and hardness
...
The heat of hydration is 500 J/g
...
It hydrates andhardens
slowly and takes long time to add to the strength (after a year or more)
...
Rising of C 2 S content renders clinker harder to grind, reducesearly strength,
decreases resistance to freezing and thawing at early ages and decreases heat ofhydration
...
At early ages, less than a month, C 2 S has little
influence on strength and hardness
...
The heat of hydration is 260 J/g
...
5 per cent) of cement
...
The rapidity ofaction is regulated by the
addition of 2-3% of gypsum at the time of grinding cement
...
Raising the C3A content reduces the setting time, weakens

17

* Under revision

resistance to sulphate attack and lowers the ultimate strength, heat of hydration and
contractionduring air hardening
...

Tetracalciumalumino ferrite
It constitutes about 8–14% (normally about 9 per cent) of cement
...
It has poorest cementing value
...
The heat of hydration is 420 J/g
...
Also present are small amounts of clinker sulfate (sulfates of sodium,
potassium and calcium) and gypsum, which was added when the clinker was ground up to
produce the familiar grey powder
...
We can get an indication of the rate at which the minerals are reacting by
monitoring the rate at which heat is evolved using a technique called conduction
calorimetry
...
Soon after mixing, the (C 3 A) phase (the
most reactive of the four main clinker minerals) reacts with the water to form an aluminaterich gel (Stage I on the heat evolution curve above)
...
(C 3 A) reaction is with water is strongly exothermic
but does not last long, typically only a few minutes, and is followed by a period of a few
hours of relatively low heat evolution
...
The first part of the dormant period, up to perhaps half-way through, corresponds to when
concrete can be placed
...
At the end of the dormant period, the alite and belite in the cement start to react,
with the formation of calcium silicate hydrate and calcium hydroxide
...
The
individual grains react from the surface inwards, and the anhydrous particles become smaller
...
The period of
maximum heat evolution occurs typically between about 10 and 20 hours after mixing and
then gradually tails off
...
Where OPC has been partly-replaced by other materials, such as fly
ash, strength growth may occur more slowly and continue for several months or even a
year
...


Products of Hydration

18

* Under revision

During Hydration process several hydrated compounds are formed most important of which
are, Calcium silicate hydrate, calcium hydroxide and calcium aluminium hydrates which is
important for strength gain
...
It is
often abbreviated, using cement chemists' notation, to "C-S-H," the dashes indicating that no
strict ratio of SiO 2 to CaO is inferred
...

The Si/Ca ratio is somewhat variable but typically approximately 0
...
50 in hydrated
Portland cement but up to perhaps about 0
...

Calcium hydroxide:
The other products of hydration of C3S and C2S are calcium hydroxide
...
It
constitutes 20 to 25 per cent of the volume of solids in the hydrated paste
...
The calcium
hydroxide also reacts with sulphates present in soils or water to form calcium sulphate which
further reacts with C3A and cause deterioration of concrete
...

To reduce the quantity of Ca (OH) 2 in concrete and to overcome its bad effects by converting
it into cementitious product is an advancement in concrete technology
...
However, Ca(OH)2 is alkaline in nature
due to which it resists corrosion in steel
...
The hydrated aluminates do
notcontribute anything to the strengthof concrete
...
As it hydrates very fast itmay contribute a little to the earlystrength
...
These are
either field test or lab tests
...

Field test:
There are four field tests may be carried out to as certain roughly the quality of cement
...

Colour

19

* Under revision

• The colour of cement should be uniform
...
e
...

Physical properties
• Cement should feel smooth when touched between fingers
...

Presence of lumps
• Cement should be free from lumps
...

Strength
• A thick paste of cement with water is made on a piece of thick glass and it is kept
under water for 24 hours
...

Laboratory tests:
Six laboratory tests are conducted mainly for assessing the quality of cement
...

Fineness
• This test is carried out to check proper grinding of cement
...

• In sieve test ,the cement weighing 100 gm is taken and it is continuously passed for
15 minutes through standard BIS sieve no
...
The residue is then weighed and this
weight should not be more than 10% of original weight
...
This test
is better than sieve test
...

Compressive strength
• This test is carried out to determine the compressive strength of cement
...

• Water is added to mortar in water cement ratio 0
...

• The mortar is placed in moulds
...
For 70
...

• Then the mortar is compacted in vibrating machine for 2 minutes and the moulds are
placed in a damp cabin for 24 hours
...

• The cubes are then tested in compression testing machine at the end of 3days and 7
days
...

Consistency

20

* Under revision

•
•
•
•
•
•
•
•

The purpose of this test is to determine the percentage of water required for preparing
cement pastes for other tests
...

Mix water and cement thoroughly
...
75 to 4
...

Vicat apparatus consists of aneedle is attached a movable rod with an indicator
attached to it
...

The plunger is attached to the movable rod
...

The settlement of plunger is noted
...
If not process is repeated with
different percentages of water till the desired penetration is obtained
...
The test is
performed to find out initial setting time and final setting time
...

• Square needle is attached to moving rod of vicat apparatus
...
In the
beginningthe needle penetrates completely
...
(upto 5mm from bottom)
• Initial setting time =<30min for ordinary Portland cement and 60 min for low heat
cement
...

• The needle with annular collar is attached to the moving rod of the Vicat apparatus
...
The time at which the needle makes an impression on
test block and the collar fails to do so is noted
...

Soundness
• The purpose of this test is to detect the presence of uncombined lime in the cement
...

• The mould is placed and it is filled by cement paste
...
A small weight is placed at top and the
whole assembly is submerged in water for 24 hours
...
The mould is again placed in
water and heat is applied in such a way that boiling point of water is reached in about
30 minutes
...

• The mould is removed from water and it is allowed to cool down
...
The difference
between the two readings indicates the expansion of cement and it should not exceed
10 mm
...

• The mortar of sand and cement is prepared
...

• The mortar is placed in briquette moulds
...
It is beaten down by a standard spatula till
water appears on the surface
...

• The briquettes are kept in a damp for 24 hours and carefully removed from the
moulds
...


22

* Under revision

3
...
Often,
additives and reinforcements are included in the mixture to achieve the desired physical
properties of the finished material
...
Over time, the cement forms a hard matrix which
binds the rest of the ingredients together into a durable stone-like material with many uses
...
The amount of each material (ie cement, water and aggregates) affects the properties
of hardened concrete
...
Each of the four constituents has a specific function
...
The fine aggregate fills up the voids between the paste and the
coarse aggregate
...
The mobility of the
mixture is aided by the cement paste, fines and nowadays, increasingly by the use of
admixtures
...


Batching
It i s the process of measuring concrete mix ingredients either by volume or by mass and
introducing them into the mixture
...
The proportions of
various ingredients are determined by proper mix design
...
The concrete must be workable and cohesive when plastic, then set and harden to give
strong and durable concrete
...
Proportioning concrete is a mixture of cement, water, coarse and fine aggregates and
admixtures
...
These proportions are best measured by weight
...

Cement content as the cement content increases, so does strength and durability
...
WaterContent
adding more water to a mix gives a weaker hardened concrete
...
Water to cement ratio as the water to cement
ratio increases, the strength and durability of hardened concrete decreases
...
Aggregates too much fine
aggregate gives a sticky mix
...
Mixing
concrete must be mixed so the cement, water, aggregates and admixtures blend into an even
mix
...
Machine mixing can be done on-site or be a
pre-mixed concrete company
...
Truck mixing the materials are normally added to the trucks at batching
plants and mixed for required time and speed at the plant
...
Site mixing when site mixing begin by
loading a measured amount of coarse aggregate into the mixer drum
...


Mixing
The mixing operation consists of rotation or stirring, the objective being to coat the surface
the all aggregate particles with cement paste, and to blind all the ingredients of the concrete
into a uniform mass; this uniformity must not be disturbed by the process of discharging from
the mixer
...

There are no general rules on the order of feeding the ingredients into the mixer as
this depend on the properties of the mixer and mix
...
If possible greater part of the water should also be
fed during the same time, the remainder being added after the solids
...


24

* Under revision

Compaction
The operation of placing and compaction are interdependent and are carried out
simultaneously
...
As for as
placing is concerned, the main objective is to deposit the concrete as close as possible to its
final position so that segregation is avoided and the concrete can be fully compacted
...

It is to get the concrete into position at a speed, and in a condition, that allow it to be
compacted properly
...
The
thickness of the layer should be compatible with the method of vibration so that entrapped air
can be removed from the bottom of each layer
...
If you proceed too slowly, the mix could stiffen so that it is no longer sufficiently
workable
...
On the other
hand, if you go too quickly, you might race ahead of the compacting gang, making it
impossible for them to do their job properly
...
Collision between concrete and
formwork or reinforcement should be avoided
...
You must be able to see that the
placing is proceeding correctly, so lighting should be available for large, deep sections, and
thin walls and columns
...
The
purpose of compaction is to get rid of the air voids that are trapped in loose concrete
...
For every 1% of entrapped air, the strength falls by somewhere between 5 and
7%
...
Air voids increase concrete's permeability
...
If the concrete is not dense and impermeable, it will not be
watertight
...
Moisture and air are more likely to penetrate to the reinforcement causing it to
rust
...
The required bond will not be achieved and the reinforced member will

25

* Under revision

not be as strong as it should be
...
For instance,
blowholes and honeycombing might occur
...


Curing
Curing is the process of making the concrete surfaces wet for a certain time period after
placing the concrete so as to promote the hardening of cement
...

Curing of concrete is done for the following purposes
...
Curing also helps maintain an
adequate temperature of concrete in its early stages, as this directly affects the rate of
hydration of cement and eventually the strength gain of concrete or mortars
...
Uniform temperature should be maintained throughout the concrete depth to avoid
thermal shrinkage cracks
...
Curing assists the cement
hydration reaction to progress steadily and develops calcium silicate hydrate gel, which binds
aggregates leading to a rock solid mass,makes concrete denser, decreases the porosity and
enhances the physical and mechanical properties of concrete
...

Generally there is adequate quantity of water at the time of mixing to cause the hardening of
concrete,but it is necessary to retain water until the concrete is fully hardened
...
This
increase in strength is sudden and rapid in early stages and it continues slowly for an
indefinite period
...
The resistance of concrete to abrasion is considerably
increased by proper curing
...
If rapid hardening
cement is used the curing period can be considerably reduced
...
The
compressive and flexural strengths are lowered
...
The durability decreases due to higher
permeability
...
The rate of carbonation
increases
...
The disadvantages are more prominent in those parts of surfaces which are directly
exposed or which have large surfaces compared to depth such as roads, canal, bridges,
cooling towers, chimneys etc
...

From the above mentioned factors it can be concluded environment directly influences the
process of evaporation, hence only the fresh concrete temperature can be monitored or
supervised by the concrete technologists
...
Under normal condition the average loss of water varies from 2
...
The major loss occurs in the top 50 mm layer over a period of 3 hours, the loss could be
about 5% of the total volume of that layer
...


•

The temperature should be kept minimum for dissipation of heat of hydration
...

Membrane curing-minimizing moisture loss from concrete surface by covering it with an
impermeable membrane
...

Water curing is of the following types:
Ponding: most inexpensive and common method of curing flat slabs, roofs, pavements etc
...
Care
must be taken to ensure that the water in the pond does not dry up, as it may lead to an
alternate drying and wetting condition
...

Wet coverings: water absorbent fabrics may be used to maintain water on concrete surfaces
...

Impermeable membrane curing is of following types:Formwork: leaving the form work in place during the early age of concrete is an efficient
method of curing
...
The
efficiency of this system can be enhanced by flooding the concrete surface with water, under
the plastic sheet
...
These are cost effective methods of
curing where standard curing procedures are difficult to adopt
...
Too early application dilutes
the membrane, whereas too late application results in being absorbed into the concrete
...
For concrete with low w/c
ratio, this is not a suitable process
...
These types of curing systems are adopted for
railway sleepers, concrete blocks, pipes, manhole covers, poles etc
...
Curing in hot and cold weather requires additional attention
...
Curing materials which reflect sunlight to reduce concrete
temperature must be used
...


•

Slow development of concrete strength
...
g
...
The
hygroscopic materials absorb moisture from the atmosphere and thus keep the surface damp
...


Water cement ratio and compressive strength
A cement of average composition requires about 25% of water by mass for chemical reaction
...
Nearly 100 years ago, Duff
Abrams discovered the direct relationship between water-to-cement ratio and strength,
i
...
,lesser the water used higher the strength of the concrete,since too much water leaves lots
of poresin the cement past
...
Here the water-cement ratio is the relative weight of water to the cement in the
mixture
...
4 and 0
...
In concrete, the trade off, of course,is with
workability, since very low water content result in very stiff mixtures that are difficult to
place
...


29

* Under revision

Workability
Workability is one of the physical parameters of concrete which affects the strength and
durability as well as the cost of labor and appearance of the finished product
...
e without bleeding
or Segregation
...
Definition of
Workability “The property of fresh concrete which is indicated by the amount of useful
internal work required to fully compact the concrete without bleeding or segregation in the
finished product
...
)

•

Temperature of the concrete mix

•

Humidity of the environment

•

Mode of compaction

•

Method of placement of concrete

•

Method of transmission of concrete

How to improve the workability of concrete
•

Increase water/cement ratio

•

Increase size of aggregate

•

Use well-rounded and smooth aggregate instead of irregular shape

•

Increase the mixing time

•

Increase the mixing temperature

•

Use non-porous and saturated aggregate

•

With addition of air-entraining mixtures

30

* Under revision

Workability tests:
There are 4 types of tests for workability
...
It measures the consistency or the wetness of concrete
...
A 2 ft (610 mm) long bullet nosed metal rod, (16 mm) in
diameter
...
The
cone is placed on a hard non-absorbent surface
...
At the end of the third
stage, concrete is struck off flush to the top of the mould
...
Concrete subsides
...

The slumped concrete takes various shapes, and according to the profile of slumped
concrete, the slump is termed as true slump, shear slump or collapse slump
...
A collapse
slump is an indication of too wet a mix
...
A collapse
slump will generally mean that the mix is too wet or that it is a high workability mix, for
which slump test is not appropriate
...


31

* Under revision

This test is usually used in laboratory and determines the workability of fresh concrete when
size is about 40 mm maximum
...

Compacting factor test:

Steps for performing the experiment:
•

keep the apparatus on the ground and apply grease on the inner surface of the
cylinders
...


•

For each 5 kg of aggregate mixes are to be prepared with water-cement ratio by
weight with 2
...
25 kg of cement and then add required amount of water
thoroughly until and unless concrete appears to be homogeneous
...


•

Fall the concrete to into the cylinder by bringing the concrete into standard
Compaction immediately after the concrete has come to rest and open the trap door of
lower hopper and then remove the excess concrete above the top of the cylinder by a
pair of trowels, one in each hand will blades horizontal slide them from the opposite
edges of the mould inward to the center with a sawing motion
...
Find the mass of partially compacted
concrete thus filled in the cylinder and say it W2 kg
...


•

Struck off level the concrete and weigh and cylinder filled with fully compacted
concrete
...


•

Calculate compaction factor by using the formula: C
...

Flow table with a grip and a hinge, 70 centimetres (28 in) square
...
7 in) top diameter, 25
centimetres (9
...
Water bucket and broom for wetting the flow
table
...
The
cone is placed in the center of the flowtable and filled with fresh concrete in two equal layers
layers
...
Wait 30 seconds before lifting the
coneThe cone is lifted, allowing the concrete to flow
...

Vee-Bee Test:
This test is useful for concrete having low and very low workability
...
When vibrator starts, concrete placed on the cone starts to occupy the cylindrical

33

* Under revision

container by the way of getting remoulded
...
The time required for completion of remoulding since start of
vibrator is measured and denoted as vee-bee seconds
...
Lesser is the vee-bee seconds more is the workability

34

* Under revision

4
...
to support the weight of the superimposed masonry by arch
action
...

But arches made of steel and Rcc are builtinsingle unit without the use of wedge shaped units
and are used for bridge constructions
...
it is prepared to receive the arch
Springer - first voussoirs at springing level on either side of arch which is adjacent to
skewback
Crown - highest point of extrados
Key - wedge shaped unit at crown of arch
...

Abutment - the end support of arch
Piers - intermediate support of an arcade
...

The arch may be defined as a mechanical arrangements of wedge shaped blocks of
stone or bricks which mutually support each other and entire arch is supported at ends by
piers or abutments
...

Stability consideration
•

Stability of arches depends on friction between surfaces of voussoirs and cohesion of
mortar
...

(b) For small spans , thickness at arch ring is kept uniform from crown to springing
...
5 m
= 30 cm for span between 1
...
5 m
(c) For large spans (> 7 cm) , thickness of arch ring may be increased at springing by about
20% to thickness at crown
...

(II)

Sliding of voussoirs :- To prevent sliding of one over after-:
(a) All bed joints should be perpendicular to the line of the least resistance, normally
they are made normal to the curve of arch, where they are nearly perpendicular to
the line of least resistance
...


(III)

Rotation about wedge -:To prevent this
(a) Line of resistance/thrust at any section should be within middle third of arch
height
...


(IV)

To safeguard against differential settlement :(a) Abutments should be sufficiently strong to resist the thrust of arch due to selfweight and superimposed loads
...

(b) Whatever may be the shape of arch, it should be symmetrical to avoid differential
settlement of support
...
of centres -: Outline of intrados / soffit may be formed by
a single arc / combination of arcs of various radii and centres and so named as one centre,
two centred, 3 centred arcs
* One centred arch- They have only one centre
...

(b)Gothic/Equilateral/pointed arch-Radii of arches are equal to span and centres are
on springing points
...

* Three centred arch(a)Elliptical arch-It is the form of semi ellipse, Two centres are used for making up
the ends and the third is used to draw the central position
...
Ends of the arch formed by arc,
central portion is drawn by the other 2 centres
...

*five centred arch-It looks like semi-elliptical arch
...

(ii)With centres as A and B draw arches of radius equal to span intersecting at point
C5
...
and produce indefinitely
...

(iv)Join OC1 and OC2 intersecting lines C5-2 and C5-3 and C3 and C4
...


CLASSIFICATION ACCORDING TO SHAPE FORMED BY SOFFIT/INTRADOS-:
(I)FLAT ARCH (straight/ square / camber arch)-:
The extrados is horizontal and intrados is given a slight rise/camber of about 10 to
15mm/metre width of span so as to allow for slight settlement of it
...
The depth of the arch is generally kept 3 or 4 courses of
brick
...
5m unless strengthened by steel reinforcement
...
This is not so sound in construction and so used for small inside opening or
narrow spans only
...
The centre of
the arch lies on the springing line
...
The bed joint of
voussoirs radiate from the centre of arch
...

Commonly used for arch
...
It
relieves the load of lintel or flat arch
...
These
days lintels restrict the use of relieving arch
...
Ther are 5
forms of these types of rches
...

(VIII)Venetin arch-: This one form of pointed arch which has a deper depth at crown
other than arch springing line
...

(IX) Floreutine arch-: Similar to venetian arch except that the intrados consist of a
semi circular curve
...

(X)Semi-circular arch-:It is formed by more than one centre usually 3 or 5 centres
...


39

* Under revision

(XII)Stilted arch-: (a) 2 cusped arch -:This arch with 2 cups has centres at different
level
...
This is not
structurally efficient
...
Here each
course is cantilevered out over the course below until the two sides meet
...


CLASSIFICATION

ACCORDING

TO

MATERIALS

AND

WORKMANSHIP

INVOLVED IN CONSTRUCTION
Stone ArchRubble Arch*They are made of roughly dressed stones arranged and fitted into a definite arch
shape by cement
...

*They are relatively weak and so used for interior types of works
...

*Up to a thickness of 40 cm stones are laid in one ring for full depth
...

Ashler Arch*Here strong are properly cut and dressed to true wedge shape (i
...
and size of voussoirs and the key stove of arch, a full size arch is
first set out on platform level and then sizes of stones are marked on platform after leaving a
gap for joints
...

*They have good appearance and used for superior work
...
When thickness is large, only
the stone is made of full thickness of arch ring
...

*Generally they are constructed with half brick rings
...
So joints are not appealing to eyes
...

Gauged Brick Arches
GAUGED BRICK*Bricks prepared to exact size and shape of voussoirs by cutting and dressing
...

*Hard bricks can not be used due to difficulty in cutting to true wedge shape
...

*They are cut by saw and finished by rubbing with stone
...


41

* Under revision

PURPOSE MADE BRICKWORK*Superior type arch work to get fine and thickness
...


Concrete Archery
Precast Concrete Block Archery*For small building opening, precast concrete blocks are used in cement mortar for
arch construction
...
They are without steel reinforcement
...


Monolithic Concrete Arches*They are constructed from cast in-situ concrete with / without reinforcement
depending on span and force frequently used for roofing of building, culvert and bridges
...
For large span RCC arches are used
...

*Normally arch thickness greater than 15cm up to span of 3m and beyond this 4 cm
should be added for each additional 30 cm more
...
Entire work should be kept for at least two weeks
...

*The arch is safe when line of thrust is found to total inside the thickness of the
masonry
...

This is a graphic method to construct the line of thrust for arches
...
Nevertheless, the value of this component and its position at the start / end of the
element are unknown
...

Maximum ThrustThe maximum thrust case is thrust line, or zone of thrust, which takes the
intrados once near the crown and the extrados near each springing
...


Linear Arch / Theoretical Arch / Line Of Thrust
When arch is subjected to given system of loading, the arch shape which follows the
shape of the BM diagram for a beam of some span as that of the acrh and subjected to some
loading as that in the arch is known as linear arch
...

Eddy’s TheoremIn an arch, BM at any point = horizontal thrust * vertical distance between line
of thrust and centre line of arch
(BM at any section of an arch is proportional to the ordinate/intercept between the
given arch and the linear arch
...
CAVITY WALL

A cavity wall or hollow wall is the one which consists of two separate walls called leader or
skins with a cavity or gap in between them
...

The internal leaf may be thicker than the external leaf to meet the structural
requirements
...

It also prevents the dampness to enter and act as sound insulation
...

ADVANTAGES :There is no direct contact between the inner and outer leaves of the wall (except at wall ties)
...

The cavity between the two leaves is full of air which is bad conductor of heat
...

Cavity wall have about 25% greater insulating value than the solid walls
...

The nuisanceof efflorescence is also very much reduced
...

Loads and foundation are reducedbecause offission solid
...
such wall is capable of taking load
of two storyedof the domestic type , if heavier loads are to be supported ,the thickness of
inner leaf can be increased
...

The inner and outer skins are adequately tied together by means of the special walls
ties placed in suitable arrangement , at the rate of at least ties to a square meter of
wall area
...
ties must be placed at 300mm vertical intervals at all angles
and doors and windows jambs to increase stability
...

The damp proof course should be flexible
...
PREVENTATION OF DAMPNESS:-When cavity wall construction is adopted there is
considerable decrease in the prevention of dampness from outside to inside of the building
...
HEAT INSULATION:-The air in the cavity acts as a non-conductor of heat and hence the
uniform temperature is maintained inside the building
...
SOUND INSULATION:- The considerable portion of external noise is not allowed to enter
inside the building by adopting cavity wall construction
...
LOAD ON FOUNDATION:-Due to less solid thickness of wall the loads on foundation are
considerably reduced
...
EFFLORESCENCE:-The construction of cavity wall results in the reduction of nuisance of
efflorescence to a great extent
...
ECONOMICAL:-In addition to above mentioned advantages, it is found that the
construction cost of a cavity wall is 20% less than the construction cost of a corresponding
solid wall
...

The width of cavity varies from 50mm to 100mm and it stands vertically
...


45

* Under revision

The two portions of the wall are connected by means of metal ties or specially prepared
bonded bricks
...

Where corrosion is heavy, the metal ties of copper or bronze may be adopted
...
The
arrangement of ties is kept staggered
...

As far as possible, there should be no intimate contact between two leaves of the cavity wall
...

But, as the cavity below damp-proof course does not serve any purpose ,the brickwork up to a
level of 100mm to 300mm below the damp-proofing course at plinth level may be
constructed solidly
...

Construction at opening:In the plan, the cavity is discontinued at the opening such as doors, windows, etc
...

If metal windows are provided, specially prepared metal frames can be used for this purpose
...
P
...
the D
...
C should be
extend lengthwise beyond the frame for a distance of about 150mm on either side
...

The cavity may be constructed up to the coping of the parapet wall or alternatively it may be
closed at the bottom of the parapet wall by a damp proofing course
...

Ventilation:It is necessary to provide enough ventilation to the hollow space of the cavity wall
...
The openings are to be fitted with gratings so that entry of rats and other
varmintsto the hollow space is prevented
...

Shape and slope of ties:The metal ties which are used to connect the outer and inner portions should be so shaped and
placed that water from outer portion does not pass along inner portions
...

Dropping of mortar, bats etc
...
, do not fall in
the hollow space
...
For this purpose, a wooden strip of width slightly less than that of
the hollow space, is supported on ties and it is raised as the work proceeds
...
Falling in the cavity are removed from these holes
...
It also be
seen that the vermins or mosquitoes do not find access in the cavity
...
The inside portion should have sufficient thickness to carry
safely the load coming on it
...
STAIRS

The means of communication between various floors is offered by various structures such as
stairs, lifts, ramps, ladders, escalators
...
Stairs are designed to provide an easy and quick access to different floors
...

In a residential house stairs may be provided near the entrance
...


STAIRCASE: Room of a building where stair is located
...

TECHNICAL TERMS
1
...

2
...

3
...
They are of two
types, (i) cut/open string, (ii) closed/housed string
...

• In closed string, the ends of steps are layed between straight and parallel edges of
the string
...
FLIGHT : Unbroken series of steps between the landings
...
GOING: horizontal distance between faces of two consecutive risers
...
HANDRAIL: inclined rail over the string
...
It serves as a guard
rail
...

7
...

8
...
A landing facilitates
change of direction and provides an opportunity to take rest
...
NEWEL POST: vertical member placed at ends of flights to connect ends of string and
hand rail
...
NOSING: projection part of tread beyond face of riser
...
LINE OF NOSING: imaginary line parallel to strings and tangential to nosings
...

12
...

Angle of inclination of line of nosing with horizontal
...
RISE: vertical distance between two successive treads
...
RISER: vertical member of the step, which is connected to treads
...
RUN: length of a stair in a horizontal plane which includes length of landing
...
SCOTIA: an additional finish provided to nosing to improve the elevation of the step
which also provides strength to nosing
...
SOFFIT: under surface of a stair
...

18
...
Different types are
...
The winders radiate from a common centre
...

• Waist: thickness of structural slab in RCC stair
• Carriage: a rough timber supporting steps of wooden stairs
REQUIREMENT OF GOOD STAIRCASE
•

Stairs should be so located that it is easily accessible from the different rooms of a
building
...

• It should have sufficient stair width to accommodate no
...

Generally for interior stairs, clear width may be
 at least 50cm in one/two family dwellings
 at least 90cm in hotels, motels, apartment and industrial building
 at least 1
...

• No
...

• Ample head room should be provided for tall people to give feeling of spaciousness
...
15m
...

Tread = 2
...
5 cm (wide), excluding nosing
...
5cm
Comfortable height of riser = 17
...
5cm
...
426
 Riser + tread = (42
...
5) 40-45
 2(riser) + tread = 60-64 cm 60
Take rise = 14cm, going = 30cm
...


49

* Under revision

• Stair width depends on purpose and importance of building
...
of stairways required should be controlled by maximum floor area contributory to
stairway
...
of persons using stairs/floor/55cm stairwidth)
should be 15 for hospital and nursing home
...

Should be 80 for church concert hall, museum
Should be 320 for stadium and amutementstructures
...

• Winder should be provided at lower end of flight when it is essential
...

• Live load to be considers n stairs have been stipulated by IS 875-1964
• Stairs and landings should be designed for live load of 3000kg/m
...
Straight stair:
 Here there is no change in the direction of any flight between two successive
floors
...

In parallel stair, there is complete reversal of direction occurs
...

Scissor stairs are comprised of a pair of straight runs in opposite direction and are
placed on opposite sides of a fire resistive wall
...
Turning stairs:
• Quarter turn stair :
 Provided where flight direction is to be changed by 900
 Change in direction can be affected by either introducing a quarter
space landing or by providing winders at junctions
...
They can be dog legged and
open newel
...

 In open newel stair, there is a well/opening between flights and may be
used to accommodate lift
...

• Three quarter turn stair:
 They change in the direction through 2700 or direction is changed with
its upper flight crossing the bottom one
...


3
...


Generally they are provided at the rear of a building to the access for serving
at various floors
...


Made up of stone,cast iron/RCC
...
Spiral stairs:

Similar to previous one except that the radius of curvature is small and the
stair may be supported by a centre post
...
5m
5
...

6
...


The change in direction is achieved through winders
...

7
...


The two narrow flights start from either side of mid landing
...


51

* Under revision

CLASSIFICATION OF STAIRS BASED ON MATERIALS OF CONSTRUCTION
General materials used in construction of stairs are

•

o Wooden
o Stone
o Brick
o Metals/steel
o Plane concrete
o RCC
Wooden stair
o As they are light in weight, mostly used for residential building
...

o If it is made from good timber like Teak, and thickness is about 45mm,
it becomes sufficiently fire proof and allows enough time for occupants
on upper floor to escape
...

 Scotia blocks may be provided to give additional finish to
wooden steps
...

 A metal strip may be provided on nosing of wooden step to
increase its resistance against wear and tear
...

 Sometimes risers are omitted
...

 The timber used should be free from fungal decay, insect
attack, or any defect
...


•

Metal Stair
o
o
o
o

They are not frequently/commonly used stairs
...

Common metals are CI, bronze, and mild steel
...

Main features are,
 Stringers are usually of channel section
 Tread and riser of a step may be of one unit or may not
be

52

* Under revision

 Tread and risers are supported on angles, which are
connected to stringers
...

 Spirals stairs of CI consists of CI newel fixed in center
around which the CI steps are fixed
...

•

RCC Stair
o Commonly used in all type of construction
...

o The step can be provided with suitable finishing material such
as marble, terrazzo, tiles etc
...

o They can be designed for greater widths and layer spans
...

o It is possible to pre cast a flight and place it in position by
equipments
...


53

* Under revision

7
...


Causes of Fire: The causes of various types of fire hazards are described in details:
•

Electrical hazards: Damaged wiring, Damaged plugs, Damp or wet wires, Overloaded
motors, Broken switches, outlets or sockets, Problems with lighting fixtures, Faulty
heating elements, Overloaded circuits, Liquids near computers, Computers without surge
protectors
...


•

Friction hazards: Hot bearings, Misaligned or broken machine parts, choking or
jamming materials, Poor adjustment of moving parts, Inadequate lubrication
...


Fire Load: It is the amount of heat liberated in KJ/m2 of floor area of any component by
the combustion of the content of and any combustible part of building itself
...
Low fire load: not exceeding 1
...
Moderate fire Load: 1
...
30× 106
3
...
23× 106 KJ/m2 to 4
...
Providing fire Fighting Equipment
2
...
Providing suitable means of escape
4
...


•

The expansion of the material due to heat should not be such that it leads to instability
of the structure
...


Fire resisting properties of common building materials:
Fire resisting properties of common building materials such as stone, brick, glass, steel and
concrete are described below:
a
...
Moreover, the stone is also liable to
disintegrate in to small pieces when heated and suddenly cooled
...
Brick: Bricks are not seriously affected until very high temperatures around 1200 oC to
1300 oC are reached
...


55

* Under revision

c
...
Therefore,
when this material in construction
...

d
...
To increase the timber more fire resisting, the surfaces of
timbers are coated with chemicals such as ammonium phosphate and sulphate, borax and
boric acid, zinc chloride
...
Glass: The materials are poor conductor of heat and its expansion due to heat is small
...

f
...
It behaves more or
less in the same way mild steel
...
Aluminium: Very good conductor of heat, it possess poor fire resisting properties
...
Asbestos Cement: this is non-combustible building material with low coefficient of
expansion
...


Fire Protection System: The system which protects a large area from fire by using
components such as pipes, pump sets, control panel, sprinklers or nozzles etc,, is known as
fire protection system
...
Automatic sprinkler system: Most reliable automatic means of fire fighting
...

2
...


3
...

4
...
The foam is as aggregate of air filled bubbles
...
The principal components of this system
include proportioning apparatus, concentrated storage tank, water supply, foam maker or
spray foam-heads, heat detecting devices, automatic and manual actuation devices and an
alarm system
...
Holon System: This indicates a specific family of chemicals which are produced by
replacing one or more hydrogen atoms with halogen atoms
...
An actuator is provided a cylinder control value and it is operated either by
electric or pneumatic signal when fire occurs
...
Hydrant system: in this system, the hydrants are located at suitable points and they can
be operated at suitable points and they can be operated manually or automatically
...
Water Spray System: The water spray system used for fire extinguish depends upon the
type of spray and can be sprayed in two categories:
•

Multi-fire system: water is sprayed in high velocities

•

Protective System: Fine water spray of low discharge velocity

Various types of Fire-resisting construction:
The type and age of construction are crucial factors to consider when assessing the adequacy
of existing escape routes
...
In older premises it is possible that type of construction and materials used
may not perform to current fire standards and refurbishments may have led to:
•

Cavities and voids being created, allowing the potential for the unseen spread of fire
...


•

Damaged or insufficient cavity barriers in modular building construction (e
...

CLASP or SCOLA type construction)
...
g
...


Where an escape route requires the provision of fire resisting construction (e
...
dead end
corridors or protected stairways) the following should be ensured:
•

Doors (including access hatches to cupboards, ducts and vertical shafts linking
floors), walls, floors and ceilings protecting escape routes should be capable of
resisting the passage of flame and smoke for long enough for people to escape from
the building (normally 30 min)
...


57

* Under revision

•

Cavity barriers, fire stopping and dampers in ducts are appropriately installed as
required
...
A fire starting in a
building constructed mainly from readily combustible material will spread faster than one
where modern fire-resisting construction materials have been used
...

Because of the requirements of the Building Regulations you will probably already have
some walls and floors that are fire-resisting and limitations on the surface finishes to certain
walls and ceilings
...

The following paragraphs give basic information on how fire-resisting construction can
provide up to 30 minutes protection to escape routes
...
If you are still unsure of the level of fire-resistance that is necessary after
reading this information, you should consult a fire safety expert
...
Common examples of types of construction that provide 30-minute fire
resistance to escape routes if constructed to the above standards are:
•

Internal framed construction wall, non-load bearing, consisting of 72mm x 37mm
timber studs at 600mm centres and faced with 12
...


•

Internal framed construction, non load- bearing, consisting of channel section steel
studs at 600mm centres faced with 12
...


Figure 1: Fire-resisting construction

There are other methods and products available that will achieve the required standard of
fire resistance and may be more appropriate for the existing construction in your premises
...


Fire-resisting floors

The fire resistance of floors will depend on the existing floor construction as well as the type
of ceiling finish beneath
...

In older buildings there may be a requirement to provide fire resistance between beams and
joists
...
5mm with joints taped and filled and backed by
supporting timber
...
If you
are in any doubt you should ask the advice of a competent person and ensure that the
product is installed in accordance with instructions from the manufacturer or supplier
...
Clear fire-resisting glazing is available and can quickly be identified by a
mark etched into the glass, usually in the corner of the glazed panel, to confirm its fireresisting standard
...

The glazing should have been installed in accordance with the manufacturer’s instructions
and to the appropriate standard, to ensure that its fire-resisting properties are maintained
...
Alternatively, where there is a
lack of test information, ask for an assessment of the proposed construction from suitably
qualified people
...
This may result in unseen fire spread
and a loss of vital protection to the escape routes
...


CLASP and SCOLA type construction

CLASP (Consortium of Local Authorities Special Programme) and SCOLA (Second
Consortium of Local Authorities) are total or systematic methods of construction that were
developed to provide consistent building quality, while reducing the need for traditional
skilled labour
...
This
results in hidden voids through which fire may spread
...
If you are in any doubt as to
whether any remedial work will be required, then ask for advice from a competent person
...

The passing of services such as heating pipes or electrical cables through fire-resisting
partitions leaves gaps through which fire and smoke may spread
...
Competent contractors should install such products
...
Most materials that are used as surface linings will fall into one
of three classes of surface spread of flame
...


Note: Additional finishes to these surfaces may be detrimental to the fire performance of the
surface and if there is any doubt about this then consult the manufacturer of the finish
...
Additionally,
timber, hardboard, block-board, particle board, heavy flock wallpapers and
thermosetting plastics will be suitable if flame-retardant treated to achieve a Class 1
standard
...


Strong room construction:
This type of construction is adopted to protect important documents, wealth, currency notes
from fire and thieves
...

1
...

2
...


3
...


62

* Under revision

8
...
to get smooth finish is
termed as plastering
...
Lime mortar used shall have fat lime to sand ratio of 1: 3 or 1: 4
...
Cement mortar of 1: 4 or 1: 6 mix is very
commonly used for plastering, richer mix being used for outer walls
...

The objectives of plastering are:
1
...
To give smooth surface to avoid catching of dust
3
...
To protect the wall from rain water and other atmospheric agencies
5
...

Requirement of good plaster are:
•

It should adhere to the background easily
...


•

It should prevent penetration by moisture
...


•

It should possess good workability
...


Materials for plastering:
Lime mortar is usually applied in 3 coats while cement mortar is applied in two or three coats
for the stone and brick masonry
...
For concrete building blocks many times only one coat of cement mortar is
applied
...
The final coat provides smooth
surface
...
The average thickness
of first coat is 10 to 15 mm
...
The final coat is just 2 to 3 mm

63

* Under revision

thick
...
Such coats are used on
concrete surfaces not exposed to rain
...
Flat lime is recommended for plastering work
...
The materials are thoroughly mixed in dry condition before
water is added to them
...


•

Water proof mortar: This mortar is water proof and it is prepared by mixing one part of
cement and two parts of sand and pulverised alum at the rate of 120 N per m3 sand
...
The
plasterings for two coats are as follows:
•

The mortar joints are racked out to a depth of 20 mm and surface is cleaned and well
watered
...


•

The first coat of plaster is now applied on the surface
...
In order to maintain uniform thickness, the screeds are
formed on the wall surface by fixing dots
...

The second coat is applied after six hours and thickness of second coat is 3 mm to 2 mm
...


For plastering in three coats are similar to two coats
...


64

* Under revision

The techniques for plastering various surfaces:
•

Internal Plastering on surfaces of Brick and Concrete:

Initially, the Surface where plastering is to be done will be cleaned
...
(Using centre plumb
bob and nylon thread)
...

First coat mortar filling (1:4 Cement and Sand) up to 15 mm will be applied on surfaces
where required mortar thickness exceed 25mm
...
Vertical joint of structural columns
/ walls & brick walls will be treated by fixing 200mm width chicken mesh with wire nails /
concrete nails by centering the mesh to the vertical wall joint
...
) will be completed on brick walls and check with
the MEP drawings
...
(Material descriptions will
be submitted for the approval of the Engineer) Internal plastering on surfaces of concrete
columns, beams & walls which are aligned with surfaces of brick walls will be plastered and
other concrete surfaces will be finished with cement base easy plaster
...

•

External Wall Plastering:

Alignment and fixing level pegs on external wall surfaces will be done using the surveying
instrument / centre plumb bobs
...
First coat mortar filling (1:4 Cement and
Sand) up to 15 mm will be applied on surfaces where required mortar thickness exceed
25mm
...
Maximum width of 20mm horizontal grooves between walls and
beams will be formed by cutting using grinders with diamond wheels after plastering the wall
surface
...
External wall plaster will
be finished with rough surface
...


65

* Under revision

•

Soffit Plastering / Soffit Finishing with Cement Based Easy Plaster

The slab soffits and beams' sides and soffits which are to be smooth surfaced painted finished
will be smoothen with easy plaster (Material literature will be submitted separately) and
places where concrete surfaces are uneven, will be roughen & leveled with cement and sand
mortar plaster before applying easy plaster to make surface smooth
...


•

Concrete surfaces will be washed and cleaned
...


Different plastering techniques:
•

There are numerous plastering techniques used to plaster ceilings and walls
...

Let’s take a look at some general plastering techniques:
Dry Lining Plastering

•

Over the years, traditional Melbourne homes made use of wet plastering to ensure a
smooth finish to ceilings and walls
...
This method is favoured due to the
ease of using a plasterboard
...
4 x 1
...
Plasterers Melbourne found it a breeze to
handle and put plaster on
...
Paint can easily be applied to any surface to
ensure a warm and welcoming finish
...
As plasterboard
walls are lightweight, they offer better flexibility when it comes to planning interior or
exterior spaces on the drawing board
...
Yet another reason why it is the most preferred plastering
method as far a construction work in timber frames are concerned
...
It
enables experiences plasterers Melbourne to obtain a clean and smooth finish by covering
any surface in need of plastering with mortar, then smoothening it using trowels
...
Like
most plastering techniques, it requires skilled plasterers and enough drying time
...


Defects in Plastering
The following defects may arise in plaster work
...
Blistering of plastered surface: This is the formation of small patches of plaster
swelling out beyond the plastered surface, arising out of late slaking of lime particles
in the plater
2
...

i
...


Structural defects in building

iii
...


Movements in the background due to its thermal expansion or rapid drying

v
...


vi
...


Faulty workmanship
...
Efforescene: It is the whitish crystalline substance which appears on the surface due
to presence of salts in plaster making materials as well as building materials like
bricks, sand, cement etc and even water
...
It affects
the adhesion of paint with wall surface
...

4
...

5
...
This also results from imperfect bond
...
Popping: It is the formation of conical hole in the plastered surface due to presence of
some particles which expand on setting
7
...
Uneven surface: This is obtained purely due to poor workman ship
...


•

The bond of brickwork should be maintained properly
...
A solution of one
part of HCl or H2SO4, and five parts of clean water is prepared and it is applied with the
help of brushes on affected area
...


•

The bricks of superior nature should only be used for the brick work
...


•

The damp- proof courses should be provided at convenient places in buildings
...


•

The fresh plastered surface should be protected from surplus quantity of water such as
rain and excessive heat such as sun
...
DAMP PREVENTION
Damp prevention is a chief requirement to ensure safety of building against dampness
...

If this is not satisfied it is likely that building may become inhabitable and unsafe from
structural point of view
...

Presently all buildings are given dpc treatment
So dpc prevent entry of moisture from walls floors and basements of a buildings
The treatment given to roofs of buildings for some cause is called water proofing
...


Faulty design of structure

2
...


Use of poor quality of material in construction

These causes give rise to an easy access to moisture to the building from different points,
such as rain penetration through walls, roofs and floors etc
...
The entry of water and its movement in different
parts of the buildings are positively due to one or more of the causes listed above
(1)

Rising Of Moisture From The Ground

The subsoil or ground on which the building is constructed may be made of soils
which easily give an access to water to create dampness in building
...

This dampness further finds its way to the floors, walls etc
...


69

* Under revision

(2)

Action Of Rain Water

Whenever the faces of walls are not suitably protected from the exposer to heavy
shower of rains, they become the sources of dampness in a structure
...

Sometimes due to faulty eave courses and eave gutters, the rain water may percolate through
the roof coverings
(3)

Rain Penetration From Top Of The Wall

All parapet walls and compound walls of the buildings which have not been protected
from rain penetration by using dam proof courses or by such measures on their exposed tops
are subjected to dampness
...

(4)

Codensation Due To Atmospheric Misture

Whenever the warm air in the atmosphere is cooled it gives rise to process of
condensation
...
However the sources of dampness is prevalent only in certain
places in India, where very cold climate exist
...

So such structures which are not well drained cause dampness in buildings through the
foundations
...

(c)

Constructional Dampness

If more water has been introduced during construction or due to poor workmanship,
the walls are observed to remain in damp condition for sufficient time
...


Effect Of Dampness
The various effects (indirectly defects), caused due to dampness in buildings are mentioned
below
All effects mainly result in poor functional performance, ugly appearance and structural
weakness of the buildings
...


(b)
Presence of damp conditions causes efflorescence on building surface, which
ultimately may result in the dis-integration of bricks, stones, tiles etc
...

(c)
It may cause bleaching and flaking of the paint which results in the formation of
coloured patches on the wall surfaces and ceilings
...


(e)
The material used as floor coverings, such as tiles, are damaged because they lose
adhesion with the floor base
...

(g)
All electrical fittings get deteriorated, causing leakage of electric current with the
potential danger of a short circuit
...

(i)
Dampness when accompanied by the warmth and darkness, breeds the germs of
tuberculosis, neuralgia, acute and chronic rheumatism etc
...


71

* Under revision

Techniques And Methods Of Damp Prevention
The following precautions should be taken to prevent the dampness in buildings, before
applying the various techniques and methods described later :
(I)
The site should be located on a high ground and well drained soil to safeguard against
foundation dampness
...
below the
surface of ground or lowest point even in the wet season
...

(II)
All the exposed walls should be of sufficient thickness to safe guard against rain
penetration
...
They should not absorb water more than 1/8 of their own weight
when soaked in water for 24 hours
...
This is essential to prevent the
formation cavities and occurrence of differential settlement
...
Window sills, coping of plinth and
string courses should be slopped on top and throated on the undesirable to throw the rain
water away from walls
...


Prevention of dampness
Use of damp proofing courses or membranesThese are the layers or membranes of water repellent material such as bituminous
felts, mastic asphalts, plastic sheets, cement concrete, mortar, metal sheets which are
interposed in the building structure at all location wherever water entry is anticipated
...
Basically D
...
C is provided to prevent the water rising from the sub soil and
getting into the different part of the buildings
...
P
...
These damp proof courses may be provide
horizontally or vertically in floors, walls etc
...
P
...

While providing damp-proof courses in buildings, the following general principles should be
observed in practice
...

•
The mortar bed upon which the DPC is laid should be level, even and free from any
projections
...
Therefore, the junctions and corners, formed by walls, or walls and floors, should be
laid continuous
...
e
...
the DPC should not be
exposed on the wall surface, otherwise it is likely to be damaged by carpainters, tile
layers,etc
...
These surface
treatments can be either external or internal, the external treatment is effective in preventing
dampness where as internal one only reduces it to a certain extent
...
Painting, distempering, are given to
the exposed surfaces and also to the internal surfaces
...
A thin film of water proofing can be materials, generally employed as
waterproofing agent in surface treatments are : sodium or potassium silicates, aluminium or
zinc sulphates, barium hydroxide and magnesium sulphate in alternate applications, soft soap
and alum also in alternate applications, lime and linseed oil, coal tar, bitumen, waxes and fats,
resins, and gum, etc
...

(3) Integral damp-proofing treatment
The integral treatment consists adding certain compounds to the concrete or mortar
during the process of mixing, which when used in construction act as barriers to moisture
penetration under different principles
...
have
mechanical action principle, i
...
, they fill the pores present in the concrete or mortar and
make them denser and water proof
...
work on chemical action principle i
...
, they react chemically
and fill in the pores to act as water resistant
...
work on repulsion principle i
...
, they are used as admixtures in concrete to react with it
and become water repellent
...

(4) cavity walls

A cavity wall consist of two parallel walls/leaves/skins of masonry, separated by a
continuous air space/cavity
...


•

Out wall/leaf(exterior wall part 10cm thick)

•

Cavity/air space(5cm-8cm)

•

Inner wall/leaf(minimum 10cm thick)


The two leaves forming a cavity in between may be of equal thickness or may not be
...


Provision of continuous cavity in the wall efficiently prevents the transmission of
dampness from outer to inner wall
...

1
...

2
...
r
...

3
...


4
...


5
...


•
(5) Shot concrete(gunting)
This consists in forming an impervious layer of rich cement mortar(1:3) for water
proofing over the exposed concrete surface or over the pipes, cisterns, etc
...
Gunite is a mixture of cement and sand on well graded fine aggregate, the usual
proportion being 1:3 or1:4
...
The mix of cement and sand is then shot
under a pressure of 2-3kg/sq
...
The necessary quality of water is added by means of regulating valve
soon after the mixture comes out from cement gun
...

By this technique impervious layer of high compressive strength can be obtained (28
days strength) and so it is useful method for reconditioning/repairing old concrete works,
bricks and masonry works, which have deteriorated
...
All the
components of a structure in general and foundation, which are liable to moisture penetration
are consolidated and so made water resistant by this process
...
This
makes structure water tight and restores stability and strength
...
This technique is used for repairing structures, consolidator ground
to improve bearing capacity forming water cut offs to prevent seepage
...
DOORS AND WINDOWS

TYPES OF WINDOWS
Depending upon the manner of fixing, materials used for construction, nature of the operational
movements of shutters , etc
...

2
...

4
...

6
...


Casement windows
Sliding windows
Metal windows
Corner windows
Gable windows bay windows
Lantern or lantern lights
Skylights

CASEMENT WINDOWS:
These are the windows, the shutters of which open like doors
...


SLIDING WINDOWS:
These windows are similar to the sliding doors and the shutters moves on the roller bearings,
either horizontally or vertically
...


76

* Under revision

METAL WINDOWS:
These are now a days widely used, especially for public building
...
The metal frame may be fixed direct to the wall or it
may be fixed on a wooden frame
...
They are placed at the corner of the room
and thus they have two faces in two perpendicular direction
...

GABLE WINDOWS:
These are the windows which are provided in the gable ends of a roof
...
They maybe square , splayed,
circular, polygonal or of any shape
...
These windows admit more lights, increase opening area , provide ventilation and
improve the appearance of building
...
They maybe square or
rectangular or curved
...
The common
rafter are suitably trimmed and the skylight is erected on a curb frame
...


79

* Under revision

TYPES OF DOORS

A door is a moving structure used to block off, and allow access to, an entrance to or within an
enclosed space, such as a building or vehicle
...

Typically doors have an interior side that faces the inside of a space and an exterior side that
faces the outside of that space
...
Doors normally consist of a panel that swings on hinges or that slides or spins
inside of a space
...

EN 12519 is describing the terms which are officially used in European Member States
...
The hinges are mounted to the fixed side (known as the "hanging stile"), and the
handle, lock, bolt, and/or latch are mounted on the swinging side (known as the "latch
stile")
...
The "top rail" and
"bottom rail" are named for their positions
...

A middle rail at the height of the bolt is known as the "lock rail", other middle rails are
commonly known as "cross rails"
...

Muntin - Optional vertical members that divide the door into smaller panels
...

The panels typically fit into grooves in the other pieces, and help to keep the door rigid
...
Can be glued in or stay as a floating panel
...


81

* Under revision

Plank and batten doors:
Plank and batten doors are an older design consisting primarily of vertical slats:
•
•

Planks - Vertical boards that extend the full height of the door, and are placed side by
side filling the door's width
...
The battens hold the planks together
...
On some doors, especially
antique ones, the battens are replaced with iron bars that are often built into the hinges as
extensions of the door-side plates
...


82

* Under revision

Frame and filled doors:

83

* Under revision

This type consists of a solid timber frame, filled on one face, face with Tongue and Grooved
boards
...


Flush doors:
A flush door consists of a framework of rails and styles and it is covered with plywood
...
framed flush door :

It consists of styles, rails, horizontal ribs, vertical ribs, and plywood
...

2
...


84

* Under revision

Louvered Doors:
In this type of doors, the shutters are provided with louvers, either fully or partly
...
The louvers maybe movable
or fixed as shown in fig
...
A collapsible steel door works without hinges and it is used for
compound gates, residential building , schools, sheds, godowns , workshop, public building , etc
...


86

* Under revision

87

* Under revision

11
...
On drying it forms a thin film on the painted surface
...
The paintings are the coating of fluid materials
The functions of the paints are:
•

To protect the coated surface against possible stresses mechanical or chemical;
deterioration—physical or environmental;

•

Decorate the structure by giving smooth and colourful finish; check penetration of water
through R
...
C;

•

check the formation of bacteria and fungus, which are unhygienic and give ugly look to
the walls;

•

check the corrosion of the metal structures;

•

Check the decay of woodwork and to varnish the surface to display it to better advantage

Defects in Painting:
•

A painted building with full colour effects gives complete satisfaction
...
Unfortunately painting
defects are by no means uncommon
...


Effects of background:
•

The factors affecting durability are dampness, cleanliness, movements, chemical
reactions, etc
...
involves the use of wet
procedures
...
Emulsion
paints are somewhat better in this respect
...


•

Chemical reaction between backing material and paint film may push the paint off the
backing material and lead to softening or decolourise the paint
...
The breakdown of bond is because of the crystallization of salts below
the paint film and the discolouration is usually due to action of free lime on the pigments
...
Special chemical resistant paints should be applied in industrial areas
...
Blue and green colours tend to fade when
exposed to bright light
...

The most common defects noticed after paintings are as follow:

Blistering and peeling are swelling of the paint film and can be defined as localized loss
of adhesion between one or more coatings or between primer and parent surface
...
It occurs in nonporous coatings such as oil based paints and
enamels
...
It is brought about by moist air, oily or greasy surface, or imprisoned gases between
the painted surface and the paint film, which expand under the influence of heat
...


Checking is a mild form of cracking
...
In case the enclosed area is large the defects is called crocodiling
...
When cracks are very small and
do not enlarge with time, the top coating is flattened with emery paper and a fresh coat of
paint is applied
...
Cracks in the plaster or masonry do not let the paint to remain intact
...
Premature application of top coat before the previous coat
has completely dried
...


Flaking: It is detachment of paint film from the surface
...
The curing
methods are: Use of plastic emulsion paints, Surface should be rubbed with emery paper
before applying a fresh coat and All dirt or dust on surface should be removed prior to
painting
...

Alligatoring: One layer of paint films sliding over the other one, when a hard paint is
applied over a soft one or vice versa
...
The lower portion of the paint does not dry due to greater thickness of the
paint film which shrinks due to drying in course of time
...
This is known as running and sagging
...


Bloom: is identified as dull patches on the finished, polished or painted surface due to defect
in the quality of paint or poor ventilation
...
The reasons attributed to this defect are weathering actions, use of cheap paint, and
poor workmanship
...
The
background and its defects can be clearly visible in such a case
...
New plastered surface:
The procedures for paining a new plastered surface are:
1
...
Before applying
the paint, it is ensured that the surface is free from dust, dirt, loose matter, grease etc
...

2
...
It should be thinned with water or thinner in the recommended
manner and proportion before application
...

Dents and cracks, if any, are filled with putty using a knife applicator
...
If the required thickness is large, it should be applied in two
coats
...
Two or three
finish coats are applied
...

B
...
If any of the defects discussed
below is very much pronounced it is completely removed and the surface is painted as a
new surface
...
Painting of new woodwork
Painting of woodwork should be done with great care
...

•

Surface preparation: The wood should be well seasoned, dried, cleaned and the surface
made smooth with an emery paper
...


•

Knotting: Knots in the wood create lot of problems
...
Knotting is done so that resin
cannot exude from the knots
...


91

* Under revision

Ordinary knotting: This is also known as size knotting
...
Then a coat of red lead ground in
boiled linseed oil is applied
...
Thereafter, the process described in ordinary knotting is followed
...

•

Priming coat: The main function of priming coat or primer is to form the base for
subsequent ones
...
A second priming coat is applied after first has dried
...


•

Stopping: After the priming coat putty is applied to fill the pores of the surface
...
Colouring pigment is also added to it to match the shade of the finished
coat
...
After painting the surface in one direction, the brush is worked in
the perpendicular direction to eliminate brush marks
...
All the
successive coats are applied after drying and slight rubbing of previous coats for proper
bond
...
Painting of old woodwork:
The old paint is removed with a sharp glass piece, sand paper, paint remover or with a blow
lamp
...
The surface is then washed with soap and water and dried completely
...

E
...
Scales and rust
are cleaned by hard wire brush
...
A priming coat of red lead with
barytes and raw linseed oil is then applied over the prepared surface
...
The second coat is
given only after the first coat has dried
...


92

* Under revision

•

Old ironwork: The surface is prepared by scraping properly all the scales and rust with
emery paper
...
The old paint may be
burned with a blow lamp or by suitable solvents
...


•

Structural steel: The major problem to overcome in painting iron and steel is corrosion
due to electrolysis caused by the presence of air and moisture
...

Pure linseed oil priming coat is detrimental in that it stimulates corrosion
...
Graphite paint used for black
colour, is very durable and is not affected by sulphur films, ammonia or chlorine gases
...
Aluminium
paint is also gaining popularity because of its shining and contrast properties and heat and
chemical resistance
...
Lead or zinc paint should never be applied directly over the iron surface as it
encourages galvanic action destroying the paint
...
Painting of floor surfaces: The enamels are used for painting of floor surfaces
...
It
should be of shinning nature and quick drying type
...
Painting of concrete surfaces: The cement paint is used to paint concrete surfaces
...

The paint thus prepared should be consumed with in 2 to 3 hours
...


93

* Under revision

12
...
It is mainly a mixture of sodium silicate and
calcium silicate
...

(ii) It is cheap
...

Uses: It is used in the manufacture of glass tubes and laboratory apparatus, plate glass,
window glass, etc
...
It is mainly a mixture of potassium silicate
and calcium silicate
...

(ii) it is not easily affected by water and other solvents
...

Uses: used in manufacture of glass articles
...
It is a mixture of potassium silicate and lead sillacate
...


94

* Under revision

(ii) Easily attacked by aqueous solution
...

(iv) Specific gravity is about 3 to 3
...

(v) Turns black and opaque
...

(4) Common glass
Also known as bottle glass
...

Properties:
(i) Fuses with difficulty
...

(iii) easily attacked by acids
...


MANUFACTURING OF GLASS:
1
...
The batch house
simply houses the raw materials in large silos (fed by truck or railcar) and holds anywhere
from 1–5 days of material
...
e
...
Whether automated or manual,
the batch house measures, assembles, mixes, and delivers the glass raw material recipe
(batch) via an array of chutes, conveyors, and scales to the furnace
...
Different glass types, colors, desired quality, raw
material purity / availability, and furnace design will affect the batch recipe
...
The furnaces are natural gas- or fuel oil-fired, and operate at
temperatures up to 1,575°C
...
Types of furnaces used in container

95

* Under revision

glass making include 'end-port' (end-fired), 'side-port', and 'oxy-fuel'
...

Forming process

There are, currently, two primary methods of making a glass container: the blow and
blow method, used for narrow-neck containers only, and the press and blow method used for
jars and tapered narrow-neck containers
...
Both processes start with
the gob falling, by gravity, and guided, through troughs and chutes, into the blank moulds,
two halves of which are clamped shut and then sealed by the "baffle" from above
...
) at the open end of the container
...
The first stage moulds all the details ("finish")
around the opening, but the body of the container is initially made much smaller than its final
size
...

Referring to the mechanism, the "rings" are sealed from below by a short plunger
...

"Counterblow" air then comes up through the plunger, to create the parison
...
The parisonis inverted in an arc to the "mould side" by the "neckring
arm", which holds the parison by the "finish"
...

The neckring arm opens slightly to release its grip on the "finish", then reverts to the blank
side
...


96

* Under revision

In the press and blow process, the parison is formed by a long metal plunger which rises up
and presses the glass out, in order to fill the ring and blank moulds
...

The container is then picked up from the mould by the "take-out" mechanism, and held over
the "deadplate", where air cooling helps cool down the still-soft glass
...


The forming machines hold and move the parts that form the container
...
2 bar and low pressure - 2
...
The most widely used forming
machine arrangement is the individual sectionmachine (or IS machine)
...
The sections are in a row, and the gobs feed into each section via a moving
chute, called the gob distributor
...
(Referred to as single, double, triple and quad gob)
...


COMPOSITION OF GLASS
The following is a list of the more common types of silicate glasses, and their ingredients,
properties, and applications:
1
...
e
...
It has very low thermal expansion, is very hard, and resists high
temperatures (1000–1500 °C)
...
Fused
quartz is used for high temperature applications such as furnace tubes, lighting tubes,
melting crucibles, etc
...
Soda-lime-silica glass, window glass: silica 72% + sodium oxide (Na2O) 14
...
0% + magnesia (MgO) 2
...
6%
...
It has a high
thermal expansion and poor resistance to heat (500–600 °C)
...
Container glass is a
soda-lime glass that is a slight variation on flat glass, which uses more alumina and
calcium, and less sodium and magnesium which are more water-soluble
...

3
...
5% + alumina (Al2O3) 2
...
Stands heat expansion much better than
window glass
...
Borosilicate glasses (e
...
Pyrex) have as main constituents silica and boron oxide
...
25×10–
6
/°C[4] as compared to about 9×10−6/°C for a typical soda-lime glass[5]), making them
more dimensionally stable
...
They are commonly used for reagent bottles, optical components and
household cookware
...
Lead-oxide glass, crystal glass: silica 59% + lead oxide (PbO) 25% + potassium
oxide (K2O) 12% + soda (Na2O) 2
...
5% + alumina 0
...

Because of its high density (resulting in a high electron density) it has a high
refractive index, making the look of glassware more brilliant (called "crystal", though
of course it is a glass and not a crystal)
...
It is also more workable in the factory, but cannot stand heating very well
...
Aluminosilicate glass: silica 57% + alumina 16% + lime 10% + magnesia 7
...
0% + boric oxide (B2O3) 4
...
Extensively used for fiberglass,
used for making glass-reinforced plastics (boats, fishing rods, etc
...

6
...
Extremely clear glass,
used for fiber-optic waveguides in communication networks
...
[6] However, most optical fiber is based on
silica, as are all the glasses above
...

Following are the properties of glass which have made the glass popular and useful:
I
...


98

* Under revision

II
...

IV
...

VI
...

VIII
...

X
...

XII
...

XIV
...

XVI
...


XVIII
...


It can take up a high polish and may be used as substitute for every costly gems
...

It has no sharp melting point
...

It is an excellent electrical insulator at elevated temperatures due to the fact that glass
can be considered as an ionic liquid
...
But when the temperature rises, the ions
are permitted to flow and thus they will sustain an electric current
...

It behaves more as a solid than most solids in the sense that it is elastic
...

It is capable of being worked in many ways
...
But it
is strange to note that it is difficult to cast in large pieces
...

It is not usually affected by air and water
...

It is possible to intentionally alter some of its properties such as
fusability,hardness,refractive power etc
...

It is possible to obtain glasses with diversified properties
...

It is possible to weld pieces of glass by fusion
...
Transparency is the most used characteristic of glass
and it is due to the absence of the free electron
...

When it is heated , it becomes soft and soft with rise in temperature
...
The liquid when allowed to cool , passes to all
deegres of viscosity
...

It can also be formed into articles of desired shape
...

Due to advancement made in the science of the glass production , it is possible to
make glass lighter than cork or softer than cotton or stronger than steel
...

The glass panes can be cleaned easily by anyone of the following methods[i]By applying methylated spirit
[ii]painting the glass panes with lime wash and leaving it to dry and then washing
with clean water
...
REPAIR

1
...
Repair does not pretend to
improve the structural strength of the building
Reconstruction
If the original building or some elements of the building missing or critically damaged to
carry out any repair, then they are re-created in all new, appropriate material
...

Rehabilitation
It is the act or process of making possible a compatible use for a property through repair,
alterations, and additions while preserving those portions or features which convey its
historical, cultural, or architectural values
...

Retrofit
Retrofitting is the process of upgrading the building which is still in good condition; so that
it becomes safe against future damage which may likely occur in near future
...


2
...
These are provided to
allow some cracking to occur there

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Control/Contraction Joints
The purpose of a control joint is todivide a large area (brick, concrete,etc
...
Control joints are usually non-workingjoints, except in the case of a brick wallwhere
they act to accommodateexpansion and contraction due to heatingand cooling
...
The most common isolation joint is the "expansion joint
...

Construction joints
A construction joint is a joint in concrete where one placement of concrete ends and the next
placement were begun after the setting up of previous work
...


3
...
Cracks in buildings could be broadly classified as
structural or non-structural type
...
E
...
, extensive cracking of an RCC beam
...
Non-structural crack
do not endanger safety of a building but may look unsightly and create a feeling of instability
and impression of faulty construction
...


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* Under revision

4
...
Examples for such repairs are removing chokage of drainage pipes,
man holes, restoration of water supply, replacement of blown fuses, repairs to faulty
switches, watering of plants, lawn mowing, hedge cutting, sweeping of leaf falls etc
...

Annual or Periodic Repairs
These are the regular repair works which are carried out at a longer time intervals, say one
year, to maintain the aesthetics of buildings and services as well as to preserve its life
...
It is necessary to prevent the structure
and services from deterioration and restore it back to its original conditions to the extent
possible
...


5
...
Building maintenance works can be classified into three categories: preventive
maintenance, routine maintenance and corrective maintenance
...


102

* Under revision

Routine Maintenance
This is the most frequently done activity of all and is done by performing routine and
scheduled maintenance of the property
...

Corrective Maintenance
These are actual repairs that keep the property functioning normally and usually need to be
done as soon as possible
...
This type of maintenance includes replacing a broken air
conditioning unit, fixing a dripping faucet, unclogging drains, replacing light bulbs, or
repairing a non-functioning toilet
...
STONES

DEFINITION- The process of taking out stones from natural rock beds is known as the
quarrying
...
The
stones, thus obtained, are used for various engineering purposes
...
In case of a mine, the operations are carried out under the ground at
great depth
...

SITE FOR QUARRY-The selection of site for a quarry of stones should be done after
studying carefully the following aspects:
1
...

3
...

5
...


Availability of tools, power, materials and labour for the efficient working of quarry
...

Economy in quarrying
...

Facility of carrying and conveying stones from quarry
...


METHODS OF QUARRYINGFollowing are the three methods of quarrying:
I
...

Quarrying with channeling machine
III
...


QUARRYING WITH HAND TOOLS-There three methods of doing this type of quarrying:
a)
b)
c)
(a)

Digging or Excavating
Heating
Wedging
Digging or Excavating- In this method, the stones are merely excavating with the
help of suitable instruments such as pick-axes, hammers, showels, chisels, etc
...

(b) Heating- In this method, the top surface of rock is heated
...
It is
suitable when the rock formation consists of horizontal layers of shallow depth
...

(c) Wedging-In this method, if rock surface contains cracks or fissures,the steel wedges
or points, as shown in fig
...

The blocks of stones are then shifted and they are removed with the help of suitable
instruments
...
The wedging is preferred to the blasting, wherever
possible
...
These machines make rapidly the grooves having length of about
24m, width of about 50mm to 75mm and depth of about 2
...
70m
...

(b) The horizontal holes are drilled beneath the rock
...

QUARRYING WITH BLASTING:In this method, the explosives are used to convert into
small pieces of stones
...

This method is adopted for quarrying hard stones, having no fissures or cracks
...
The process of blasting is important
with respect to the stone quarrying
...

Marble:
• Origin and composition: - it is a most common variety of metamorphic rock
...

• properties :- following are the properties of marble:_
• its crushing strength is from 500 to 600 kg/cm2

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•
•
•
•
•
•
•

the usual color of marble is white, but it is also available in different shades of colors such
as grey, black, red, brown, yellow and combination of these
it is compact and crystalline in structure due to which it can take a fine polish
it is les durable
Itcan be carved easily and thus is most suited for sculpture work
...
72 its weight 2720 kg/cum
its absorption is 1 to 3%
Chief uses:- used as building stone and in decorative panels

Sandstone:
•

•
•
•
•
•

Origin and composition:-This stone is a common variety of sedimentary rocks mechanical
origin
...
are also present
...

Its specific gravity is 2
...
4
...

Chief uses: - general walls building flagstone
...

It is a good heat and electrical insulator
...
5 to 1%
...

It is a valuable material for roofing and black boards
...

slate a available at the available at the following localities in India:_
o simla, kangra, gurgaon, Gurdaspur, Alwar, Rajasthan, (MP) (Haryana) (Gujarat

Basalt:•

•
•
•

Origin and Composition: these stones are the common varieties of igneous rocks they are
formed by solidification of lava on the earth’s surface due to volcanic eruption
...
They are chiefly composed
of silica, alumina and felspar
...
cm
...

Their specific gravity (2-9 to 2
...

They are available as a vast deposit of basaltic rock, near the western Ghats of India,
known as Deccan trap
...
Varieties of basalts jike, Bombay Basalt, Blue basalt, red basalt and
yellow basalt are found and used in Maharasatra, Gujarat etc
...

Texture :- fine to crystalline, may have fossils
Parting :-parallel to beds: also may have irregular fractures
...

All lime stone are of sedimentary origin and have for their principal ingredient
carbonate of lime
...

Granite:-

•

•

•

Granite is one of the most valuable stones for construction purposes
...

The hardest and most durable granites contain a greater proportion of quartz anda smaller
proportion of feldspar and mica
...

Because of its uniform structure, granite can be quarried in large blocks
...
The uses for which granite is suitable
depend on the texture of the stone
...
Fine-grained stone can be carved and polished
...
It is composed chiefly of minerals that cleave readily, such as hornblende,
mica, etc
...
The
presence of the cleavage minerals produces a fine cleavage or foliation, called
schistosity
...
It should always be set with the planes of schistosity
horizontal
...

• It is formed by metamorphism of either sedimentary or igneous rock
...

Shale • Shale is a typical clay rock that splits readily in lines parallel to the
bedding
...

• Shale is used for light traffic roads and in the manufacture of brick,tile,
and other burned clay products, but it is not suitable for
concrete
aggregate
...
, cemented together is known as
conglomerate
...

When the interstices between the pebbles are not filled by the binder, the rock is
very porous, and may hold great amounts of ground water
...


108

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15
...
the function of the trunk
is to support the crown and to supply water and nutrients from the roots to the leaves through
branches and from the leaves back to the roots
...

Details of structure:
From the visibility aspect,the structure of tree can be divided into two categories :(1)
...
Microstructure
Macrostructure:The structure of wood visible to the naked eye or at a small magnification is called the
macrostructure
...
It varies in
size and shape and for different types of trees
...
when the plant becomes old,the pith dies up and decays
and the sap is then transmitted by the woody fibres deposited round the pith
...


109

* Under revision

(2) Heartwood:
The inner annular rings surrounding the pith constitute the heart wood
...
as a matter of fact ,it indicates the dead portion of tree and as such,it does not take
active part in the growth of the tree
...

(3) Sapwood:
The outer annular rings between heartwood and cambium layer is known as sapwood
...
It indicates recent growth and it contains sap
...
It takes active part
in the growth of the tree and the sap moves in upward direction through it
...

(4) Cambium layer
The thin layer of sap between sapwood and inner bark is known as the cambium layer
...
If the bark is removed for any
reason,the cambium layer gets exposed and the cells cease to be active resulting in the death
of the fibre
...
it gives
protection to the cambium layer from any injury
...
it is the outermost protective
layer and it sometimes contain cracks and fissures
...

(7) Medullary rays
The thin radial fibres extending from pith to cambium layer are known as the medullary
rays
...
these rays are sometimes broken and in some varieties of trees,they are not very
prominent
...

A living cell consists of four parts namely membrane ,protoplasm,sap and core
...
The protoplasm is a
granular,transparent
,viscous
vegetable
protein
composed
of
carbon,hydrogen,oxygen,nitrogen and sulphur
...

The cells ,according to the function they perform,are classified into the following three
categories:
-

Conductive cells

110

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-

Mechanical cells
Storage cells

(1)
...

(2)
...
these cells impart strength to the wood
...
storage cells:
These cells serve to store and transmit nutrients to the living cells in the horizontal direction
and they are usually located in the medullary rays
...
they
may also be formed by parts of a planning machine
...
it is indicated by
diagonal mark on straight grained surface of timber
...

(iv)Wane:this defects is denoted by the presence of original rounded surface on the
manufactured piece of timber
...

(2)If there is a presence of air and warmth for the growth of fungi
...


111

* Under revision

(ii) Brown rot:the fungi of certain types remove cellulose compound from wood and hence
the wood assumes the brown colour
...

(iii) Dry rot:the fungi of certain types feed on wood and during feeding ,they attack on wood
and convert it into powder form
...

This type of defect occur in place where there is dampness and no free circulation of air
...

(iv) Heart rot: this is formed when a branch has come out of a tree
...

(v) Sap stain:certain types of fungi feed on cell contents of sap wood
...
this is known as sap stain
...

(vi) Wet rot:some varietiesof fungi cause chemical decomposition of wood of timber in
doing so timber is converted into a greyish brown powder
...

(iv) White rot:this defect is opposite of brown rot
...

Defect due to insects:
Defects in timber occur dueto various types of insects
...

Defect due to natural force:
The main natural forces responsible for causing defects in timber two,namely,abnormal
growth and rupture of tissues
...
Due to such injury, the growth of tree is
completely upset and irregular projections appear on the body of timber
...

(iii) Chemical stain: the wood is sometimes discoloured by the chemical action caused with
it by some external agency
...
Such timber
possesses less strength
...


112

* Under revision

(vi)Druxiness: this defect is indicated by white decayed spots which are concealed by
healthy wood
...
It is caused due too poor ventilation
...
The portion from which the branch is removed receives nourishment from the stem for a
pretty long time and it ultimately results in the formation of dark hard rings which are known
as the knots
...
Hence peculiar
curved swelling found on the body of a tree known as the rind gall
...

Following are the different types of shakes: cup shake, heart shake, ring shake, star shake,
radial shake
...

(xii) Upset: these are also known as the ruptures and they indicate the wood fibres which are
injured by crushing or compression
...

Thi defect is usually found in converted timber
...

These are known as the wind cracks
...

(i) Bow: the defect is indicated by the curvature formed in the direction of length of timber
...
It therefore shrinks and
is under compression
...

This defect is known as the case-hardening
...
It does not extend from one
end to the other
...
This is
known as collapse
...

(vi) Honey-combing: due to stresses developed during drying, the various radial and circular
cracks in the interior portion of timber
...

(vii) Radial shake: these are radial cracks
...

(ix) Twist: when a piece of timber has spirally distorted along its length, it is known as a
twist
...

TIMBER
TIMBER is the oldest material used by humans for construction after stone
...
It is readily and economically available; easily machinable; amenable to fabrication into
an infinite variety of sizes and shapes using simple on-site building techniques;




Exceptionally strong relative to its weight
A good heat and electrical insulator
It is a renewable and biodegradable resource
...
It is a “natural”
material and is available in limited amount
...
Timber is to be seasoned well before application of preservatives
...
Tar
2
...
Chemicalsalt
4
...
ASCO
1
...
The coating of tar protects the timber from the
attack of fungi and insects
...
Main disadvantage of
this method of preservation is that appearance is not good after tar is applied it is not possible
to apply other attractive paints
...

2
...
The paint protects the
timber from moisture
...
Paint improves the
appearance of the timber
...

3
...
The salts used are copper

114

* Under revision

sulphate, masonry chloride, zinc chloride and sodium fluoride
...

4
...
The seasoned timber is kept in an air tight
chamber and air is exhausted
...
8 to 1
...
After 1 to 2 hours timber is taken out of the
chamber
...
ASCO
This preservative is developed by the Forest Research Institute, Dehradun
...
(CuSO4⋅5 H2O) and 4 parts by weight of potassium dichromate (K2Cr2O7) or
sodium dichromate (Na2Cr2O7⋅2 H2O)
...
By
mixing six parts of this powder with 100 parts of water, the solution is prepared
...
This treatment prevents attack from termites
...


Physical Properties:
Specific Gravity (SG):
Generally, specific gravity (SG) and the major strength properties of wood are directly
related
...
30 to 0
...

Higher allowable design values are assigned to those pieces having narrower growth rings
(more rings per inch) or more dense latewood per growth ring and, hence, higher SG
...
The
combination of high relative humidity or MC and high temperatures, as in unventilated attic
areas, can have serious effects on roof sheathing materials and structural elements over and
above the potential for attack by decay organisms
...

At temperatures above 220°F, wood takes on a thermoplastic behavior
...

Environmentally friendly
Timber is the most environmentally responsible building material
...
Timber is a renewable resource
...


115

* Under revision

In plentiful and growing supply
Timber is readily available
...
6 million hectares, and the area is growing rapidly
...
A comparison with steel and concrete shows that radiata pine
structural timber, for example, has a strength for weight ratio 20 percent higher than
structural steel and four to five times better than unreinforced concrete in compression
...
Building components and
complete constructions are simple and safe to erect, and cheaper to deconstruct or reuse at the
end of a buildingís useful life
...
Some species have proven very useful for food containers (berry boxes and
crates) because they are nontoxic and impart no taste to the foods contained therein
...
The fungus feed
upon the wood and eats the wood tissue, thus penetrating the wood fibres from all direction
...
well seasoned timber should be used
...
timber should be used where there is free circulation and access of air
...
the timber should be painted with a solution of copper sulphate
2
...

WET ROT
The disintegration of tissue of timber due to alternate wetting and drying is called wet rot
...

Prevention:
All timber for exterior or underground work should
be first properly seasoned and then coated with tar to keep out the dampness
...
From childhood
days woodencots and toys, to school desks and, eventually, to wooden furniture and flooring
in homes or places of employment - seasoned timber is to be found
...
It is to be regretted thateven some people associated with
the timber tradehave little knowledge of what seasoned timber is andthe best method of
obtaining it
...
Water is just as essential to the life of atree as it is for
all living matter
...
The food, that is the sugars and
starch,are made in the leaves by photosynthesis and aretransported in solution down the inner
bark to thegrowing cells
...
Consequently,when the tree is felled and the resulting logis sawn into
timber, the sawn sections consist ofinnumerable small cells containing water
...

Why is timber seasoned?
Seasoning timber causes many changes in its properties, and in practically every case
the change is animprovement
...
However, by a correct understandingof the
shrinkage of timber this effect can be minimized,and timber can then be confidently
usedwithout fear of adverse behaviour subsequently inservice
...
Air seasoning is
carried out in a shed with a platform
...
1
...


(ii)
Care is taken to see that there is proper air circulation around each timber balk
...
A well-seasoned timber
contains only 15% moisture
...

Water seasoning is carried out on the banks of rivers
...
After a period of 2 to 4 weeks the timber is taken out
...
Then
timber is stalked in a shed with free air circulation
...
Seasoning can be completed in 4
to
5
days
only
...


(a) Boiling: In this method timber is immersed in water and then water is boiled for 3 to 4
hours
...
Instead of boiling water hot steam may be circulated on
timber
...

(b) Kiln Seasoning: Kiln is an airtight chamber
...

Thenfully saturated air with a temperature 35°C to 38°C is forced in the kiln
...
Then relative humidity is gradually reduced and temperature
is increased, and maintained till desired degree of moisture content is achieved
...
In progressive kiln the carriages
carrying timber travel from one end of kiln to other end gradually
...
This method is used for seasoning on a larger scale
...
Then the timber is dried in a kiln
...

(d) Electrical Seasoning: In this method high frequency alternate electric current is passed
through timber
...


118

* Under revision

As moisture content reduces the resistance reduces
...

However it is costly process
...

Different methods of seasoning:
Air Seasoning
The traditional method for drying wood, air seasoning is also the longest, taking six to nine
months
...
The raised pallets also keep
wood away from vegetation and damp ground
...
Protect the drying wood from
the elements with an overhead canopy
...

Drying takes two days to one weekend, depending on the type of wood
...
In a progressive kiln, timber
enters at one end and travels on a trolley through chambers with different air conditions to
progressive dry the wood
...
Wood
seasoned via the compartmental process remains in a single building where it is subjected to a
program of varying conditions until the moisture content is removed
...

Solar Kiln
This method combines the speed of kiln seasoning with the low energy of air drying
...
Heat collectors, made from black metal are attached near the top of
the window sashes
...
Some solar kilns have insulation to retain heat at night
...
Because of its gentle nature, it is
well suited to producing wood for furniture fabrication
...
This method also provides advantages such
as high speed and high quality and is well suited for seasoning lumber, blocks, veneer, chips,
paper and wood-based composite materials
...
These factors enhance quality and reduce timber checking and warping
...
Seasoned timber lasts much longer than unseasoned
...

2
...

3
...
Few persons
realize how much water green wood contains, or how much it will lose in a comparatively
short time
...

Freight charges vary considerably in different parts of the country; but a decrease of 35 to
40 per cent in weight is important enough to deserve everywhere serious consideration from
those in charge of timber operations
...


120

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16
...
Nature of subsoil
...
Nature and extent of difficulties
3
...
This type of foundation is practicable for a depth up to 5m and is
normally convenient above the water table
...
Since spread foundations are constructed in open excavations,
therefore they are termed as open foundations
...
Wall footings,
2
...
Combined footings,
4
...
Continuous footings
6
...
Grillage footing
1
...
The base course of these
footings can be concrete or of entirely one material
...
The width of the concrete base should be at
least equal to twice the width of the wall
...
Generally the projection provided in the footing is 15cm, on either side

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and the concrete mix comprises of cement, sand and aggregate in proportion of 1:3:6 or
1:4:8
...
Isolated or Column Footings: They are used to support individual columns
...
Generally, 15cm offset is
provided on all sides of concrete bed
...

3
...
The
combined footing can be rectangular in shape if both the columns carry equal loads or
can be trapezoidal if both the loads are unequal
...
The location of the center of the gravity of the column loads and
centroid of the footing should coincide
...
Inverted arch footing: This type of footing is used on soft soils to reduce the depth of
the foundation
...
In this type of footings the end columns must bes stable
enough to resist the outward pressure caused by the arch action
...
Continuous footings: In this type of footing a single continuous R
...
slab is provided as
foundation of two or three or more columns in a row
...
This also prevents differential settlements in
structures
...
Strap or cantilever footings: Strap footing consists of two or more individual footings
connected by a beam called strap
...

7
...
This type of arrangements prevents deep
excavations and provides necessary area at base to reduce the intensity of the pressure
...
They are used where the soil mass contains compressible lenses
so that the differential settlement would be difficult to control
...
The raft is
composed of reinforced concrete beam with a relatively thin slab underneath
...
These foundations are in
general used as basements, buoyancy rafts, caissons, cylinders, shaft and piles
1
...
They are constructed in place in an open excavations
...

2
...
They are hollow substructures designed to provide a buoyant
substructure beneath which reduce net loadings on the soil to the desired low density
...
Caissons
...

4
...
They are single small cell caissons
...
Shaft Foundations
...

6
...
The pile foundation is a construction supported on piles
...

The piles may be placed separately or they may be placed in form of a cluster throughout
the structure
...
Classification based on function: Bearing Pile, Friction Pile, Screw Pile, compaction
Pile, Uplift Pile, Batter Pile and Sheet Pile
2
...


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---