Bricks moulding Unit-3 (Bricks).pptx Unit-3 (Bricks).pptx

Introduction:
Bricks Moulding Clay Rectangular blocks
(Obtained) (in)
Reasons For Choosing Brick
1.Uniform Size
2.Light in weight
3. Stone
Can be arranged easily
Easily lifted ( Lifting appliances not required)
Easily not available
(of)
Uniform size
Drying
Burning
3. Brick replaces stone Plenty of clay is available

Comparison Of Brick work And Stone Work
1.Stone Not easily available Brick work Cheaper
(becomes)
Clay is
available
in plenty
(provided)
2.Cost of construction
(is)
Less
(in)
Brick work Skilled workmanship is
not required
(because)
3 Lifting appliances
(not required)
Bricks
(can be)
Easily moved
(with)
Manual labor
4 Bricks
(resist)
Fire
(do not)
Disintegrate
5 Openings and connections
(can be)
Easily constructed Brick work
(in)

Classification Of Bricks
 Based on field practice a) 1st Class bricks
b) 2nd Class bricks
c) 3rd Class bricks
d) 4th Class bricks
 1st Class bricks
1. These are table moulded
2. Surfaces and edges are sharp, square , smooth and straight
3. Well burnt and have uniform structure , metallic ringing
sound when struck against each other
4. Used for superior work

 2nd Class bricks
1. These are ground moulded bricks
2. These surfaces are rough
3. The quality of these bricks are inferior
 3rd Class bricks
1. The surface and edges are rough
2. Does not create any metallic sound
3. Used for temporary and unimportant structures
 4th Class bricks
1. These bricks are over burnt
2. Irregular shape and dark color
3. Used as aggregate for concrete in foundations ,
floors , roads etc

Classification Of Bricks
 Based on uses a) Common bricks
b) Engineering bricks
c) Facing bricks
 Common bricks
1. Low quality bricks
2. Low compressive strength
3. Used for internal walls ( which is not seen)
4. No uniform color, texture or appearance

 Engineering bricks
1. High in compressive strength
2. Low water absorption
3. Particularly used for below ground level
construction
4. Used in areas of exposure of water
 Facing bricks
1. High quality
2. Uniform appearance
3. Used extremely in areas of
“Seen brick work”

Properties Of Bricks
 Bricks should be table moulded
 Well burnt in the kilns
 Color – copper color
 Sharp and square edges
 Free from cracks
 Uniform in shape and size
 Should be of standard size
 Clear ringing sound
 1st class bricks – should not absorb more than 20% of water by weight
( when soaked in cold water for 24 hours)
 2nd class bricks – should not absorb more than 22% of water by weight
( when soaked in cold water for 24 hours)
 Bricks should be sufficiently hard
 Bricks should not break into pieces when dropped on a flat hard ground
from a height of 1m

Properties Of Bricks
 Bricks should have low thermal conductivity
 They should be sound proof
 When soaked in water for 24 hours bricks should not show the deposits of
white salts when dried in shade

Defects in Bricks
1. Name of the defect: Over burning of bricks
Purpose of the defect: Due to burning of bricks more than desired temperature
Result: Hard and loose their shape (not used for construction)
2. Name of the defect: Under burning of bricks
Purpose of the defect: Due to not burning of bricks at desired temperature
Result: More absorption of water and less compressive strength
(not used for construction)
When brick-clay contains bituminous matter or carbon
and they are not completely removed by oxidation
3. Name of the defect: Black core
Purpose of the defect:
Result: The brick results in black core mainly because of improper burning
(Not used in construction)

Defects in Bricks
Check & cracks
4. Name of the defect:
Purpose of the defect: Due to lumps of lime and excess of water
Result: Shrinkage and cracks occur
Spots
Purpose of the defect: Due to the presence of iron sulphate in brick earth
Result: Dark surfaces are formed on bricks which makes it not suitable for
exposed brick work
Purpose of the defect: Sulphates react with alumina content of cement and
with hydraulic lime in the lime mortar
Result: Increase in the volume of mortar
Results in chipping and spalling of bricks
Formation of cracks in the joints
Most attacked elements: Exposed boundary walls, parapet walls, retaining
walls(which mostly come in contact with moisture)
Sulphate attack

Defects in Bricks
Due to corrosion of embedded iron or steel
Iron and steel embedded in the brickwork gets corroded
in the presence of dampness
Result: Metal expands in volume and tends to crack the brick work
Remedy: This defect can be prevented by covering the reinforcement or iron in
dense cement mortar and providing a cover of 15mm to 25mm around
the embedded member
Prevention of above defects in the bricks
 Prevention: By providing water proof coping
By providing water repellent materials in mortar
By providing damp proof course

Defects in Bricks
Due to shrinkage on drying
Brick work normally swells with the absorption of water
and subsequently shrinks when the water evaporates
Result: In the process of shrinkage it develops cracks in the masonry joints
If the mortar used in the masonry is lean, the cracks are distributed
over larger number of joints
In case of rich mortar the cracks are few but wider
Remedy: This defect can be prevented by using good quality bricks and by
protecting masonry from moisture penetration

How to repair cracks in brick masonry
Step- 1: An over view
Repairing eroding and cracked mortar joints is called pointing, repointing or
tuckpointing
Identifying the cracks like it is vertical or
horizontal cracks
Picture- 1

Cut grooves 3/4 to 1 in. deep in cracked or
deteriorating mortar using a 4-1/2 in. angle
grinder fitted with a diamond blade. Push the
blade into the joint until the grinder head contacts
the brick, and make a single pass along the center
of the joints
Step- 2: Tools and materials
Angle grinder
Picture- 2

Cleaning out old mortar joints requires basic tools: hammer, flat utility chisel
(Photo 2), safety glasses, dust mask and whisk broom
Filling the cleaned-out joints requires masonry tools: brick trowel (Photo 5), 3/8-in.
pointing trowel (Photo 5), a special tool for contouring the joints (Photo 7) and
waterproof gloves

Step- 3: Break out the old mortar
Picture- 3
Break out old mortar using a hammer and cold
chisel or a flat utility chisel that's narrow enough to
fit into the joints (Photo 3)
Wear safety glasses and a dust mask and remove
3/4 to 1 in. of old mortar (more if needed) until you
reach a solid base for bonding the new mortar
If the mortar is so soft that the bricks are loosening up, you'll have to remove
and properly reset them
To avoid nicking the bricks, cut the vertical joints before cutting the horizontal
joints

Step- 4: Clean the joints
Once the old mortar is removed, dust out the
joints (Photo 4). Prepare the joints to receive new
mortar by misting them lightly with a garden hose
sprayer
Picture- 4
Clean out all the loose dust from the brick
cavity using a whisk broom

Step- 5: Mix the mortar just right
Picture- 5
Dump mortar mix into a cement “boat” and
gradually add the specified amount of water
while mixing with a brick trowel. Allow the
mortar to “rest” for 10 minutes, then remix it
before using. The mix is right when it sticks to an
overturned trowel

Step- 6: Fill the joints with mortar
Picture- 6
Load mortar onto an overturned brick trowel,
hold the trowel under the horizontal joint—
tight to the brick—and sweep 1/4-in. slivers of
mortar into the cavity using a 3/8-in. wide
pointing trowel. Fill the horizontal joints first.
Avoid getting mortar on the brick face

Step- 7: Match the new joints with the old
Picture- 7
Drive a 6d box nail into a short 1x2 board so
that it matches the depth of the existing joints.
To “rake” joints, hold the board perpendicular
to the bricks and move it back and forth, first
along the vertical joints and then the
horizontal joints. Other joint profiles require
other shaping tools

Step- 8: Match the new joints with the old
Picture- 8
Sweep the loose mortar from the
finished joints and brick faces using a soft-
bristle brush. Mist the new mortar twice a
day for two days using a hand pump
sprayer or a light mist from a garden hose
to help it harden

Common mortar joint profile
Raked Joint
http://www.familyhandyman.com/masonry
/how-to-repair-mortar-joints/view-all
V-Joint Concave Joint
Flush Joint
Bibliography

Name of the defect:
Result:
Efflorescence on outer wall surfaces
This defect is caused because of alkalies present in bricks
When bricks come in contact with moisture, water is
absorbed and the alkalis crystallize
On drying grey or white powder patches appear on the brick surface
Remedy for efflorescence: By brushing and washing the effected area repeatedly
How to repair efflorescence defect in brick masonry
To remove alkali efflorescence, use a weak solution
of muriatic acid and water
Use a nylon bristled brush to scrub very gently to
minimize splashing

If you're going to deal with efflorescence on an
interior surfaces where you don't want to use a
dangerous acid, try using a strong vinegar solution in
place of the muriatic acid. Boil a cup of vinegar
down to a half cup. This will double the normal acid
in the vinegar which may be effective on some
efflorescence problems
Name of the defect:
Result:
Efflorescence on interior walls surfaces
This defect is caused because of alkalies present in bricks
When bricks come in contact with moisture, water is
absorbed and the alkalis crystallize
On drying grey or white powder patches appear on the brick surface
Remedy for efflorescence:
How to repair efflorescence defect in brick masonry

How to repair Pealing plaster on brick masonry
Step – 1: Remove any flaked or peeling paint from the
masonry
If the wall has already been painted, you need to
remove any old paint that is loose, peeling, or flaking
away
On an exterior wall, this is most efficiently done with
a sandblaster
loose paint can be removed with a stiff wire brush
and a paint scraper
Sand Blaster

Step – 2: Clean the brick wall
Like other surfaces, masonry should be cleaned
before painting
The best product for cleaning brick is trisodium
phosphate (TSP)
This compound can be purchased in powder form at hardware stores, or a
cleaning product that contains TSP can be used, such as Spic and Span
Mix the TSP with water in a bucket according to the manufacturer's directions.
Apply the resulting mixture to the brick with a scrub brush, allowing it to
thoroughly dry before proceeding with the painting process

Step – 3: Apply a masonry sealer to the wall
Because most masonry is more porous and more
highly textured than materials such as drywall or wood,
the extra step of applying a sealer is necessary before
priming and painting
Step – 4: Apply primer to the masonry wall
Both oil-based and latex-based primers will work
well on masonry
Step – 5: Paint the brick wall
Like priming, painting masonry can be
accomplished with ordinary latex or oil paints,
although masonry paints are available that increase
the wall's ability to repel moisture
http://www.wikihow.com/Paint-Masonry-Walls
Bibliography

Brick damage or Brick Spalling is typically caused by
excessive moisture or water infiltration of the interior
brick courses of your Masonry walls
Brick Masonry is designed to get wet and shed water
when it rains, but when water is allowed to infiltrate the
walls through faulty mortar joints or damaged roof
copings, the walls do not dry-out sufficiently
When your Brick Masonry is continually wet, the brick
begins to decay, and Brick Replacement becomes
necessary, this can involve just a few Brick, or hundreds.
These areas are the most vulnerable for this kind of
brick damage, particularly on many of the older or
historic homes
How to repair spalling in brick masonry
Brick
replacement
involves carefully
cutting out and
actually replacing
deteriorated bricks
with full size
matching or very
closely-matching
bricks

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