BRICKS REPORT

RABI MUKHI AMIN

TITLE : BRICK

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 1.FIRST CLASS BRICK
1.1 INTRODUCTION

First Class Brick: The size is standard. The color of these

bricks is uniform yellow or red. It is well burnt, regular
texture, uniform shape. The absorption capacity is less
than 10%, crushing strength is, 280 kg/cm2 (mean) where it is 245 kg/cm2 (minimum). It doesn’t have
efflorescence. It emits a metallic sound when struck by another similar brick or struck by a hammer. It
is hard enough to resist any fingernail expression on the brick surface if one tries to do with a
thumbnail. It is free from pebbles, gravels or organic matters. It is generally used-

It is generally used-

• In a building of long durability, say 100 years

• For building exposes to a corrosive environment;

• For making coarse aggregates of concrete.

1.2 BASED ON MATERIAL

a. Silica (SiO2) Free silica (sand) is a main constituent, if added to clay in suitable proportion makes
hard and prevents it from warping and shrinkage on drying. Silica, if present in greater proportion, makes
a brick brittle. Silica present in the combined form (aluminum silicate) does not form good bricks, as it
will shrink and develop cracks.
b. Alumina (Al2O3) Alumina is one of a main constituents of every clay. Loam soil (adhesive soil)
forms good clay. In absence of sand, pure clay will develop cracks due to shrinkage on drying and
burning. A good clay bricks should contain about 20% of alumina. Alumina absorbs water and renders
the clay plastic. If alumina is present in excess of the specified quantity, it produces cracks in brick on
drying. Clays having exceedingly high alumina content are likely to be very refractory. Both silica and
alumina should be in free form.

C-Lime (CaCO3): Normally constitutes less than 10 percent of clay. This also should be present in
small quantities in the brick earth. It should be in a finely produced condition and it should not be in the
form lamps or clods. Lime prevents shrinkage of raw bricks on drying. It helps fusion of sand at the kiln
temperature. This fused sand will bind the bricks particles fast.

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 d- Iron oxide: A small quantity of oxide of iron (5-6%) is desirable. It helps the fusion of sand like
lime. It gives red colure to burn bricks. Excess of iron oxide imparts dark blue or blackish colure to brick,
while, a lower percentage of iron oxide makes the brick yellow in colure. Iron oxide makes the bricks
hard and strong.

e. Magnesia: Rarely exceeding 1 percent affects the color and makes the brick yellow. A small amount
of magnesia helps to decrease the shrinkage of bricks. This gives a yellow tint to the bricks. But excess
of magnesia is not desirable as it tends to produce the decay of bricks

❖ SILICA

• Percentage: - 50% to 60%

• Function: -

➢ Prevents brick from shrinkage, cracking & warping.

• Effect of Excess: -

➢ Makes brick brittle and useless

❖ ALUMINA

• Percentage: - 20% to 30%

• Function: -

➢ Absorbs water and imparts plasticity to clay so that it can properly molded.

• Effect of Excess: -

➢ Shrink and warp during drying & burning.

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❖ LIME

• Percentage: - should not exceed 5%

• Function: -

➢ Binding particles together.

➢ It allows sand to fuse or to melt during burning.

• Effect of Excess: -

➢ Cause to brick melt and loose it's shape.

❖ OXIDES OF IRON

• Percentage: - 5% to 6%
• Function: -

➢ Imparts colour.
➢ It helps to fuse the lime & sand during burning.

➢ Bind particles to give hardness & Strength.

• Effect of Excess: -

➢ Bricks becomes dark blue.

❖ MAGNESIA

• Percentage: - about 1%
• Function: -

➢ Decrease shrinkage
➢ Gives yellow tint to brick.

• Effect of Excess: -

➢ Decay of Brick.

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1.3 COMPOSITION

First class bricks are known for their superior quality and durability, and their composition is a key factor
in achieving these properties. Here’s a detailed look at the composition and characteristics of first class
bricks:
1. Raw Materials

A. Clay
• Primary Component: The main raw material for first class bricks is clay, which is mixed with
other materials to improve the quality of the bricks.
• Types of Clay: The quality and type of clay used can vary, but it generally includes:
o Common Clay: For standard bricks.
o Fire Clay: For bricks requiring higher heat resistance.
o Shale: Used in some high-quality bricks for its fine texture.
B. Additives
• Sand: Added to clay to reduce shrinkage and improve the workability of the brick mixture.
• Lime: Used in small quantities to enhance the durability and bonding properties of the bricks.
• Iron Oxide: Added to achieve specific colors, such as red or brown.
• Alumina: Enhances the strength and resistance of bricks.
2. Manufacturing Process

A. Preparation of Raw Materials

1. Mixing:
o Clay is mixed with sand and other additives to form a homogeneous mixture.
o The proportions of each material are carefully controlled to ensure the desired properties
of the final product.
2. Molding:
o The mixture is shaped into bricks using molds. This can be done by hand or using
automated machinery.
o Bricks are typically molded into a standard size, but custom sizes and shapes can be
created as needed.
3. Drying:
o Moulded bricks are dried to remove excess moisture. This is usually done in a drying
chamber or under controlled conditions.
o Proper drying prevents warping and cracking during the firing process.
4. Firing:
o Dried bricks are fired in a kiln at high temperatures (typically between 800°C to 1,200°C
or 1,472°F to 2,192°F).

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 o The firing process hardens the bricks, giving them their final strength, color, and
durability.
B. Quality Control
• Uniformity: Ensuring the bricks are uniform in size, shape, and color.
• Strength Testing: Checking the compressive strength to ensure it meets the required standards.
• Durability Testing: Evaluating resistance to weathering, absorption, and other factors.

2. Properties of First Class Bricks

A. Physical Properties
• Compressive Strength: Typically high, often exceeding 70-100 kg/cm². This ensures the bricks
can withstand substantial loads.
• Water Absorption: Low water absorption rate, usually less than 20%, which enhances durability
and reduces susceptibility to weathering.
• Density: Generally high, contributing to the strength and durability of the brick.
B. Thermal Properties
• Thermal Insulation: Good thermal insulation properties due to the air pockets within the brick
structure.
• Fire Resistance: Excellent fire resistance, making them suitable for use in fire-resistant
construction.
C. Aesthetic Properties
• Color: Can range from red, brown, and yellow to other colors depending on the additives used.
• Texture: Can be smooth or textured, depending on the moulding and finishing processes.

3. Standards and Specifications

First class bricks must meet certain standards to be classified as such. These standards typically include:
• Size and Shape: Adherence to standard dimensions (e.g., 190 mm × 90 mm × 90 mm).
• Strength: Minimum compressive strength requirements.
• Absorption: Maximum allowable water absorption levels.
• Durability: Resistance to weathering and other environmental factors.

5. Application

Given their high quality, first class bricks are used in various high-demand applications:
• Building Facades: For their durability and aesthetic appeal.
• Structural Walls: In load-bearing walls and structural elements.
• Paving: For driveways, walkways, and other surfaces.

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1.4 APPLICATION

First-class bricks are high-quality bricks used in construction due to their superior properties. Here
are some common applications of first-class bricks:
1. Load-Bearing Walls: First-class bricks are often used in the construction of load-bearing walls
due to their high compressive strength and durability.

2. External Walls: These bricks are ideal for external walls as they offer excellent weather
resistance and have uniformity in size, shape, and color.

3. Foundations: First-class bricks are used in foundation work to ensure a strong and stable base
for buildings and other structures.

4. Flooring: They can be used for creating durable and aesthetically pleasing flooring in various
types of buildings.

5. Pavements: First-class bricks are used in pavements and walkways, offering a durable surface
that can withstand heavy foot traffic.

6. Fireplaces: Due to their ability to withstand high temperatures, first-class bricks are suitable for
constructing fireplaces and chimneys.

7. Fencing and Boundary Walls: These bricks are used to construct fences and boundary walls,
providing security and aesthetic appeal.

8. Archways and Pillars: First-class bricks are also used in the construction of decorative archways
and structural pillars.

9. Retaining Walls: Their strength makes them suitable for retaining walls that need to support a
large amount of earth.

10. Decorative Work: Due to their smooth finish and uniform appearance, first-class bricks are used
for decorative purposes in both interior and exterior design.

11. Water Reservoirs and Tanks: First-class bricks are used in the construction of water reservoirs
and tanks because they do not absorb water easily, ensuring the structure remains intact.
These applications highlight the versatility and reliability of first-class bricks in various construction
projects.

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 1.5 COSTING

The cost of first-class bricks in India can vary based on several factors, including location,
availability, and the supplier. As of 2024, the approximate price range for first-class bricks is as
follows:
1. Cost per Brick:
o In urban areas, the price can range from ₹7 to ₹10 per brick.
o In rural areas, the price might be slightly lower, ranging from ₹6 to ₹9 per brick.
2. Cost per 1,000 Bricks:
o In urban areas, the cost for 1,000 first-class bricks can be between ₹7,000 to ₹10,000.
o In rural areas, the cost for 1,000 bricks might range from ₹6,000 to ₹9,000.
3. Bulk Purchase:
o For large construction projects, bulk purchasing may result in discounts, reducing the cost
per brick.
4. Delivery and Transportation:
o Additional costs for delivery and transportation may apply, especially if the construction
site is far from the brick kiln or supplier. These costs can vary based on the distance and
mode of transport.
5. Regional Variations:
o Prices can vary significantly from one region to another due to differences in local
production costs, demand, and availability of raw materials.
6. Quality and Brand:
o The cost may also vary based on the brand and the specific quality of the bricks. Bricks
from well-known and reputable manufacturers may be priced higher due to their
guaranteed quality.
For the most accurate and up-to-date pricing, it's recommended to contact local suppliers or check
online marketplaces and construction material stores in your area.

Current Pricing (2024 Estimates)

• Per Brick: ₹7 - ₹10 (urban), ₹6 - ₹9 (rural)

• Per 1,000 Bricks: ₹7,000 - ₹10,000 (urban), ₹6,000 - ₹9,000 (rural)

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1.6 SIZE

The standard size of first-class bricks in India is regulated by the Bureau of Indian Standards (BIS).
According to the IS 1077:1992 specification for common burnt clay building bricks, the standard
size of a first-class brick is as follows:

Standard Size:
• Modular Size: 190 mm x 90 mm x 90 mm
• Non-Modular Size: 230 mm x 110 mm x 70 mm
These sizes are considered standard for building construction, but variations can occur based on
regional practices and specific requirements of a construction project.

Tolerances:
• Length: ±3% (for modular size)
• Width: ±3% (for modular size)
• Height: ±3% (for modular size)

Additional Considerations:
• Frog Dimensions: First-class bricks often have a depression (frog) on one or both flat faces. This
helps in holding the mortar and improving the bond between bricks. The frog's depth is generally
about 10 to 20 mm.

• Edge and Surface: First-class bricks have sharp edges and a smooth surface, ensuring uniformity
and better aesthetics in construction.
These sizes and specifications ensure that first-class bricks meet the necessary strength, durability,
and appearance standards required for high-quality construction projects.

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 2. SECOND CLASS BRICK
2.1 INTRODUCTION

Second-class bricks, while slightly lower in quality compared to first-class bricks, are still widely used
in various construction applications. The standard size and specifications for second-class bricks are
generally similar to those of first-class bricks, but there are some differences in quality and finish.

2.2 BASED ON MATERIAL

a. Silica (SiO2) Free silica (sand) is a main constituent, if added to clay in suitable proportion makes
hard and prevents it from warping and shrinkage on drying. Silica, if present in greater proportion, makes
a brick brittle. Silica present in the combined form (aluminum silicate) does not form good bricks, as it
will shrink and develop cracks.
b. Alumina (Al2O3) Alumina is one of a main constituents of every clay. Loam soil (adhesive soil)
forms good clay. In absence of sand, pure clay will develop cracks due to shrinkage on drying and
burning. A good clay bricks should contain about 20% of alumina. Alumina absorbs water and renders
the clay plastic. If alumina is present in excess of the specified quantity, it produces cracks in brick on
drying. Clays having exceedingly high alumina content are likely to be very refractory. Both silica and
alumina should be in free form.

C-Lime (CaCO3): Normally constitutes less than 10 percent of clay. This also should be present in
small quantities in the brick earth. It should be in a finely produced condition and it should not be in the
form lamps or clods. Lime prevents shrinkage of raw bricks on drying. It helps fusion of sand at the kiln
temperature. This fused sand will bind the bricks particles fast.

d- Iron oxide: A small quantity of oxide of iron (5-6%) is desirable. It helps the fusion of sand like
lime. It gives red colure to burn bricks. Excess of iron oxide imparts dark blue or blackish colure to brick,
while, a lower percentage of iron oxide makes the brick yellow in colure. Iron oxide makes the bricks
hard and strong.

e. Magnesia: Rarely exceeding 1 percent affects the color and makes the brick yellow. A small amount
of magnesia helps to decrease the shrinkage of bricks. This gives a yellow tint to the bricks. But excess
of magnesia is not desirable as it tends to produce the decay of bricks

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 ❖ SILICA

• Percentage: - 50% to 60%

• Function: -

➢ Prevents brick from shrinkage, cracking & warping.

• Effect of Excess: -

➢ Makes brick brittle and useless

❖ ALUMINA

• Percentage: - 20% to 30%

• Function: -

➢ Absorbs water and imparts plasticity to clay so that it can properly molded.

• Effect of Excess: -

➢ Shrink and warp during drying & burning.

❖ LIME

• Percentage: - should not exceed 5%

• Function: -

➢ Binding particles together.

➢ It allows sand to fuse or to melt during burning.

• Effect of Excess: -

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 ➢ Cause to brick melt and loose it's shape.

❖ OXIDES OF IRON

• Percentage: - 5% to 6%
• Function: -

➢ Imparts colour.
➢ It helps to fuse the lime & sand during burning.

➢ Bind particles to give hardness & Strength.

• Effect of Excess: -

➢ Bricks becomes dark blue.

❖ MAGNESIA

• Percentage: - about 1%
• Function: -

➢ Decrease shrinkage
➢ Gives yellow tint to brick.

• Effect of Excess: -

➢ Decay of Brick.

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2.3 COMPOSITION

1. Silica (SiO₂):
o Percentage: 50-60%
o Role: Silica, primarily in the form of sand, is a major component that contributes to the
strength and rigidity of the brick. It helps in reducing shrinkage and warping during firing.
High silica content ensures the brick remains dimensionally stable and maintains its
shape.
2. Alumina (Al₂O₃):
o Percentage: 20-30%
o Role: Alumina provides plasticity, making the clay easier to mold. It also helps in binding
the clay particles together. However, excessive alumina can lead to a reduction in the
strength of the brick and increased water absorption.
3. Lime (CaO):
o Percentage: 2-5%
o Role: Lime acts as a flux, aiding in the melting and fusion of clay particles during the
firing process. This improves the hardness and density of the brick. Too much lime can
cause the brick to become overly porous or prone to spalling.
4. Iron Oxide (Fe₂O₃):
o Percentage: 5-7%
o Role: Iron oxide contributes to the color of the brick, typically giving it a reddish hue. It
also plays a role in the vitrification process, which enhances the brick’s durability.
Variations in iron oxide content can lead to color variations.
5. Magnesia (MgO):
o Percentage: Less than 1%
o Role: Magnesia contributes to the hardness and color of the brick. It helps in the formation
of a hard, dense brick body. High levels of magnesia can lead to efflorescence or affect
the brick’s stability.
6. Alkalis (K₂O, Na₂O):
o Percentage: Less than 1%
o Role: Alkalis are usually present in minimal amounts to avoid efflorescence and other
issues. Excessive alkalis can lead to surface deposits of salts and affect the appearance
and performance of the brick.

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Manufacturing Process:

1. Clay Preparation:
o Extraction: Clay is mined from natural deposits.
o Weathering: The clay is left exposed to weather conditions to improve its workability
and remove excess moisture.
o Grinding and Mixing: The clay is ground to break down lumps and mixed with water to
achieve a workable consistency. Additives like sand or fly ash may be mixed to improve
certain properties.
2. Molding:
o Hand Molding: Clay is manually placed into molds, which can lead to variations in size
and shape. This method is often used for lower-quality bricks.
o Machine Molding: Bricks may be molded using machines, resulting in more uniform
size and shape, though this is less common for second-class bricks.
3. Drying:
o Air Drying: The molded bricks are air-dried for several days. This step reduces moisture
content to prevent cracking during firing.
4. Firing:
o Traditional Kilns: Second-class bricks are often fired in traditional kilns or clamps,
which can result in less uniform firing compared to modern kilns.
o Temperature: The firing temperature is typically between 900 to 1000 degrees Celsius.
Inconsistent firing can lead to variations in strength and color.
5. Cooling and Sorting:
o Cooling: After firing, the bricks are cooled slowly to avoid thermal shock.
o Sorting: Bricks are sorted based on quality. Second-class bricks may have more surface
defects and irregularities compared to first-class bricks.
Characteristics:
• Surface: Second-class bricks may have a rougher surface and more visible imperfections, such
as cracks and irregularities. The color may be less uniform.
• Strength: They have lower compressive strength compared to first-class bricks but are still
suitable for many construction applications. They are often used in non-load-bearing walls or
internal partitions.
• Durability: Less durable and more prone to damage, especially in exposed conditions. Suitable
for internal use or as backup walls behind finishes.
• Water Absorption: Higher water absorption compared to first-class bricks, which can impact
their performance in damp conditions.
Impurities:
• Organic Matter: May cause uneven burning and defects if not adequately removed.

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 • Salts: Presence of salts can cause efflorescence, resulting in white deposits on the surface.
• Coarse Particles: Higher levels of coarse particles can lead to surface roughness and uneven
texture.
Second-class bricks offer a cost-effective alternative for various construction applications, providing an
adequate balance between performance and cost. However, they may not meet the same standards of
uniformity, strength, and appearance as first-class bricks.

2.4 APPLICATION

Second-class bricks, due to their slightly lower quality compared to first-class bricks, are used in a
variety of construction applications where high strength and perfect appearance are not critical. Here’s
a detailed look at the typical applications of second-class bricks:
Applications of Second-Class Bricks:
1. Internal Walls:
o Partitions: Suitable for internal partition walls and non-load-bearing internal walls.
They provide adequate structural support where aesthetic and high strength are less
critical.
o Interior Finish: Used as a base layer for plaster or other finishes where the surface
imperfections will be covered.
2. Backup Walls:
o Facade Support: Used behind decorative or facing bricks. Second-class bricks provide
structural support while the external finish or veneer covers their appearance.
3. Boundary Walls and Fences:
o Perimeter Walls: Ideal for constructing boundary walls, garden walls, and fences where
durability is important but perfect aesthetics are less critical.
o Security Walls: Used in areas where high security is needed, but the wall doesn’t
require a polished finish.
4. Temporary Structures:
o Construction Sites: Often used in temporary structures or storage sheds on construction
sites due to their lower cost and adequate durability.
5. Septic Tanks and Soak Pits:
o Waste Management: Suitable for constructing septic tanks, soak pits, and other utility
structures where high strength is not crucial but durability and functionality are needed.
6. Foundation in Light Structures:
o Support for Lightweight Buildings: Used in the foundations of lightweight or non-load-
bearing structures. They provide necessary support without requiring the higher strength
of first-class bricks.
7. Pavements and Walkways:
o Low-Traffic Areas: Used in pavements and walkways where there is minimal load or
traffic. They are cost-effective for areas that do not require high durability or aesthetics.
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8. Garden Walls:
o Landscaping: Commonly used in garden walls, retaining walls, and other landscaping
features. The imperfections can be concealed with plants or other decorative elements.
9. Internal Chimneys and Flues:
o Non-Exposed Areas: Suitable for constructing internal chimneys, flues, or other
components where the bricks are not exposed to the elements and do not need to meet
high aesthetic standards.
10. Sub-Floors:
o Base Layer: Used as a base layer under flooring where high strength is not a primary
concern, such as in certain types of flooring systems.

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1.5 COSTING

The cost of second-class bricks can vary significantly based on factors such as location, local market
conditions, and the specific quality of the bricks. Here’s a general overview of the costing for second-
class bricks in India:
General Cost Range:
• Per Brick: The cost of second-class bricks typically ranges from ₹5 to ₹10 per brick, depending
on factors such as quality, size, and local availability.
• Per 1000 Bricks: The price per thousand bricks generally falls between ₹5000 and ₹10000.
Factors Affecting Cost:
1. Location:
o Prices can vary based on geographic location and local market conditions. Brick prices
tend to be higher in urban areas compared to rural areas.
2. Quality and Size:
o Slight variations in quality and size can influence the price. Bricks with fewer
imperfections or those that are larger may be priced higher.
3. Manufacturing Costs:
o Costs associated with raw materials, labor, and manufacturing processes can affect the
price of bricks. Traditional methods may be less expensive compared to automated
processes.
4. Transportation:
o The cost of transporting bricks from the manufacturing site to the construction site can
add to the overall cost, especially if the distance is significant.
5. Local Demand:
o Fluctuations in demand and supply can impact pricing. High demand or limited supply
can drive up prices.
6. Additives and Impurities:
o Bricks containing additional additives or higher levels of impurities might be priced
differently. However, second-class bricks generally have fewer additives compared to
higher-quality bricks.
Regional Price Variations:
• Metro Cities: In major metropolitan areas like Mumbai, Delhi, or Bangalore, the cost of second-
class bricks might be on the higher end of the spectrum due to increased demand and higher
transportation costs.
• Rural Areas: In rural or less-developed areas, prices may be lower due to lower transportation
costs and less demand.
Additional Costs:

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• Delivery Charges: These can add to the overall cost depending on the distance and logistics
involved.
• Taxes and Fees: Local taxes, VAT, and other fees may apply and should be considered in the
overall cost.
Example Cost Calculation:
• Cost Per Brick: ₹7
• Cost Per 1000 Bricks: ₹7000
• Additional Costs: Delivery charges (e.g., ₹500) and taxes (e.g., ₹500) might bring the total cost
to approximately ₹8000 to ₹8500 for 1000 bricks.

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 2.6 SIZE

Second-class bricks in India are generally manufactured to standard sizes, though some variation may
occur depending on local practices and specific requirements. The typical sizes for second-class bricks
are:
Standard Sizes for Second-Class Bricks:
1. Common Brick Size:
o Dimensions: 190 mm × 90 mm × 90 mm
o Description: This is the most commonly used size for second-class bricks, also known
as the standard brick size.
2. Other Variants:
o Modular Brick Size:
▪ Dimensions: 200 mm × 100 mm × 75 mm
▪ Description: Slightly larger than the common brick size, used in some regions for
modular construction.
o Half Brick Size:
▪ Dimensions: 190 mm × 90 mm × 45 mm
▪ Description: Used for specific applications where a thinner brick is required.
Key Points:
• Thickness Variations: While the length and width are generally consistent, the thickness of
second-class bricks can vary slightly due to less stringent manufacturing controls compared to
first-class bricks.
• Manufacturing Tolerances: Second-class bricks may have slight variations in size and shape,
which can affect the uniformity of the finished wall or structure. Tolerances in size are generally
broader than those for first-class bricks.
• Local Standards: In some regions, local standards or practices may lead to variations in brick
sizes. It is always advisable to verify the exact dimensions with local suppliers or manufacturers.

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3. THIRD CLASS BRICK

3.1 INTRODUCTION

Third-class bricks are a lower-grade type of brick compared to first and second-class bricks. They
are typically used in applications where aesthetic and structural requirements are less stringent.
Here’s a detailed introduction to third-class bricks:

3.2 BASED ON MATERIAL

a. Silica (SiO2) Free silica (sand) is a main constituent, if added to clay in suitable proportion makes
hard and prevents it from warping and shrinkage on drying. Silica, if present in greater proportion, makes
a brick brittle. Silica present in the combined form (aluminum silicate) does not form good bricks, as it
will shrink and develop cracks.
b. Alumina (Al2O3) Alumina is one of a main constituents of every clay. Loam soil (adhesive soil)
forms good clay. In absence of sand, pure clay will develop cracks due to shrinkage on drying and
burning. A good clay bricks should contain about 20% of alumina. Alumina absorbs water and renders
the clay plastic. If alumina is present in excess of the specified quantity, it produces cracks in brick on
drying. Clays having exceedingly high alumina content are likely to be very refractory. Both silica and
alumina should be in free form.

C-Lime (CaCO3): Normally constitutes less than 10 percent of clay. This also should be present in
small quantities in the brick earth. It should be in a finely produced condition and it should not be in the
form lamps or clods. Lime prevents shrinkage of raw bricks on drying. It helps fusion of sand at the kiln
temperature. This fused sand will bind the bricks particles fast.

d- Iron oxide: A small quantity of oxide of iron (5-6%) is desirable. It helps the fusion of sand like
lime. It gives red colure to burn bricks. Excess of iron oxide imparts dark blue or blackish colure to brick,
while, a lower percentage of iron oxide makes the brick yellow in colure. Iron oxide makes the bricks
hard and strong.

e. Magnesia: Rarely exceeding 1 percent affects the color and makes the brick yellow. A small amount
of magnesia helps to decrease the shrinkage of bricks. This gives a yellow tint to the bricks. But excess
of magnesia is not desirable as it tends to produce the decay of bricks

20
 ❖ SILICA

• Percentage: - 50% to 60%

• Function: -

➢ Prevents brick from shrinkage, cracking & warping.

• Effect of Excess: -

➢ Makes brick brittle and useless

❖ ALUMINA

• Percentage: - 20% to 30%

• Function: -

➢ Absorbs water and imparts plasticity to clay so that it can properly molded.

• Effect of Excess: -

➢ Shrink and warp during drying & burning.

❖ LIME

• Percentage: - should not exceed 5%

• Function: -

➢ Binding particles together.

➢ It allows sand to fuse or to melt during burning.

• Effect of Excess: -

➢ Cause to brick melt and loose it's shape.

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 ❖ OXIDES OF IRON

• Percentage: - 5% to 6%
• Function: -

➢ Imparts colour.
➢ It helps to fuse the lime & sand during burning.

➢ Bind particles to give hardness & Strength.

• Effect of Excess: -

➢ Bricks becomes dark blue.

❖ MAGNESIA

• Percentage: - about 1%
• Function: -

➢ Decrease shrinkage
➢ Gives yellow tint to brick.

• Effect of Excess: -

➢ Decay of Brick.

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 3.3 COMPOSITIOThe composition of third-class bricks reflects their lower quality
compared to first and second-class bricks. These bricks are made using less refined materials

and processes, leading differ chemical and physical makeup. Here’s a detailed breakdown of the
typical composition of third-class bricks:

Composition of Third-Class Bricks:

1. Silica (SiO₂):

o Percentage: 50-60%

o Role: Provides strength and rigidity. In third-class bricks, the silica content may be less
uniform, leading to variable strength and structural integrity.

2. Alumina (Al₂O₃):

o Percentage: 20-30%

o Role: Contributes to the plasticity of the clay and helps in binding the clay particles.
The alumina content may be inconsistent, affecting the molding and strength.

3. Lime (CaO):

o Percentage: 2-5%

o Role: Assists in the fusion of clay particles during firing, contributing to hardness. In
third-class bricks, lime content can be variable, potentially impacting the final hardness
and durability.

4. Iron Oxide (Fe₂O₃):

o Percentage: 5-7%

o Role: Imparts color to the bricks and aids in vitrification. The iron oxide content in
third-class bricks may be inconsistent, leading to uneven coloring

5. Magnesia (MgO):

o Percentage: Less than 1%

o Role: Contributes to color and hardness. The content in third-class bricks is typically
minimal, and variability can affect brick performance.

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6. Alkalis (K₂O, Na₂O):

o Percentage: Less than 1%

o Role: Minimal presence to avoid efflorescence. Higher levels of alkalis in third-class

bricks can lead to surface deposits and affect appearance.

Impurities and Variations:

1. Organic Matter:

o Presence: Higher levels of organic material compared to first and second-class bricks.
Organic impurities can cause uneven burning and lead to defects like cracks and
warping.

2. Salts:

o Presence: Higher levels of salts may be present, which can lead to efflorescence (white,
powdery deposits on the surface).

3. Coarse Particles:

o Presence: Higher presence of coarse particles and other impurities can result in a rough
surface and uneven texture.

Manufacturing Variations:

• Clay Quality:

o The clay used is often of lower quality and may contain more impurities, leading to
variability in the final product.

• Molding and Drying:

o Hand molding and air drying are common, resulting in less uniform size and shape, and
increased likelihood of surface imperfections.

• Firing Process:

o Fired in traditional kilns or clamps with less controlled temperatures, leading to uneven
firing and variations in strength and color.

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3.4 APPLICATION

Third-class bricks are used in construction where high strength, durability, and aesthetic quality are not
critical. Here’s a detailed overview of their typical applications:
Applications of Third-Class Bricks:
1. Non-Load-Bearing Internal Walls:
o Partitions: Used for internal partition walls in buildings where high structural strength is
not required. These bricks are ideal for dividing spaces in residential or commercial
buildings.
o Interior Finish: Often used as a base layer for plaster or other finishes, where
imperfections will be covered.
2. Boundary Walls and Enclosures:
o Perimeter Walls: Commonly used for boundary walls or fences around properties. They
provide a functional barrier without the need for a polished appearance.
o Garden Walls: Suitable for garden walls and other landscaping features where durability
and aesthetics are secondary concerns.
3. Temporary Structures:
o Construction Sites: Frequently used in temporary buildings, storage sheds, or other
provisional structures at construction sites due to their lower cost and sufficient durability.
o Site Offices: Used for constructing site offices or other temporary facilities where high
quality is not required.
4. Utility Structures:
o Septic Tanks: Employed in constructing septic tanks and soak pits, where functionality
is more important than appearance.
o Soak Pits: Used in drainage systems or soak pits where durability under load is not a
major concern.
5. Pavements and Walkways:
o Low-Traffic Areas: Suitable for pavements, walkways, or paths where the load and
traffic are minimal. They offer a cost-effective solution for low-demand areas.
6. Sub-Floors and Base Layers:
o Support Layers: Used as a base layer under flooring systems where structural strength
is less critical. This includes areas like sub-floors or base courses.
7. Non-Structural Walls:
o Backup Walls: Can be used behind decorative or facing bricks in structures where the
appearance of the third-class bricks will not be visible.
o Retaining Walls: Used in non-critical retaining walls where the primary function is to
hold soil or other materials rather than to support structural loads.

25
 8. Brickwork for Service Areas:
o Utility Areas: Suitable for walls or enclosures around utility areas, service rooms, or
warehouses where high strength and finish are not essential.
Key Considerations:
1. Surface Imperfections:
o Third-class bricks often have surface irregularities, so they are typically used in
applications where appearance is not a major concern and where the surface can be
covered or finished.
2. Durability:
o These bricks are less durable and more prone to weathering compared to higher-class
bricks. They should not be used in exposed conditions or where high structural
performance is required.
3. Cost-Effectiveness:
o Due to their lower cost, third-class bricks are a budget-friendly option for various
construction needs, making them ideal for projects with tight financial constraints.

26
3.5 COSTING

The cost of third-class bricks is generally lower than that of first and second-class bricks due to their
reduced quality and manufacturing standards. Here’s a detailed overview of the costing for third-
class bricks in India:
Cost of Third-Class Bricks:
1. Per Brick:
o Range: Typically between ₹4 to ₹8 per brick.
o Factors Influencing Cost: Prices can vary based on location, local market conditions,
and specific quality of the bricks.
2. Per 1000 Bricks:
o Range: Generally falls between ₹4000 and ₹8000 per thousand bricks.
o Additional Costs: The final cost can be influenced by additional factors such as
transportation, taxes, and delivery charges.
Factors Affecting Cost:
1. Location:
o Urban vs. Rural: Prices may be higher in urban areas due to increased demand and
higher transportation costs. Rural areas may see lower prices.
2. Quality and Size:
o Variability: Slight variations in brick quality and size can affect pricing. Even within the
third-class category, there might be differences in cost based on the extent of
imperfections or irregularities.
3. Manufacturing Costs:
o Raw Materials: Costs of raw materials, labor, and manufacturing processes can impact
the price. Third-class bricks are typically produced with less stringent quality controls,
which can affect overall costs.
4. Transportation:
o Logistics: Delivery costs can vary depending on the distance from the manufacturing site
to the construction site. Longer distances generally mean higher transportation costs.
5. Local Demand:
o Supply and Demand: Fluctuations in local demand and supply conditions can influence
brick prices. High demand or limited supply can drive prices up.
6. Taxes and Fees:
o Regulations: Local taxes, VAT, and other regulatory fees can add to the overall cost of
third-class bricks.
Example Cost Calculation:
• Cost Per Brick: ₹6
• Cost Per 1000 Bricks: ₹6000

27
 • Additional Costs: Delivery charges (e.g., ₹400) and taxes (e.g., ₹400) might bring the total cost
to approximately ₹6800 to ₹7200 for 1000 bricks.

3.6 SIZE

The size of third-class bricks can vary somewhat due to less stringent manufacturing controls compared
to first and second-class bricks. However, they are generally produced in standard sizes used across the
industry. Here’s an overview of the typical sizes for third-class bricks:
Standard Sizes:
1. Common Brick Size:
o Dimensions: 190 mm × 90 mm × 90 mm (length × width × height)
o Description: This is the standard size for many types of bricks, including third-class
bricks. It is commonly used in various construction applications.
2. Modular Brick Size:
o Dimensions: 200 mm × 100 mm × 75 mm
o Description: Some regions use slightly larger bricks for modular construction. This size
is less common for third-class bricks but may be used depending on local practices.
3. Half Brick Size:
o Dimensions: 190 mm × 90 mm × 45 mm
o Description: These are thinner bricks used for specific applications, including partitions
or as a decorative element.
Key Points:
1. Variability:
o Size Variations: Due to less controlled manufacturing processes, third-class bricks may
exhibit more size variations compared to first and second-class bricks. This can result in
irregular shapes and dimensions.
2. Surface Quality:
o Imperfections: The surface of third-class bricks may be rough and uneven, which can
affect their uniformity and the ease of use in construction.
3. Local Standards:
o Regional Differences: The exact dimensions and sizes may vary slightly depending on
local standards and manufacturing practices. It is important to verify the specific sizes
with local suppliers or manufacturers.
4. Molding Techniques:
o Hand Molding: Often hand-molded, which can lead to inconsistencies in size and shape
compared to machine-molded bricks.

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 5.FOURTH CLASS BRICK
4.1 INTRODUCTION

Fourth-class bricks are considered to be of the lowest quality among the traditional
classifications of bricks. They are generally used in applications where aesthetic appeal and
structural integrity are not critical. Here’s a detailed introduction to fourth-class bricks:

4.2 BASED ON MATERIAL

a. Silica (SiO2) Free silica (sand) is a main constituent, if added to clay in suitable proportion makes
hard and prevents it from warping and shrinkage on drying. Silica, if present in greater proportion, makes
a brick brittle. Silica present in the combined form (aluminum silicate) does not form good bricks, as it
will shrink and develop cracks.
b. Alumina (Al2O3) Alumina is one of a main constituents of every clay. Loam soil (adhesive soil)
forms good clay. In absence of sand, pure clay will develop cracks due to shrinkage on drying and
burning. A good clay bricks should contain about 20% of alumina. Alumina absorbs water and renders
the clay plastic. If alumina is present in excess of the specified quantity, it produces cracks in brick on
drying. Clays having exceedingly high alumina content are likely to be very refractory. Both silica and
alumina should be in free form.

C-Lime (CaCO3): Normally constitutes less than 10 percent of clay. This also should be present in
small quantities in the brick earth. It should be in a finely produced condition and it should not be in the
form lamps or clods. Lime prevents shrinkage of raw bricks on drying. It helps fusion of sand at the kiln
temperature. This fused sand will bind the bricks particles fast.

d- Iron oxide: A small quantity of oxide of iron (5-6%) is desirable. It helps the fusion of sand like
lime. It gives red colure to burn bricks. Excess of iron oxide imparts dark blue or blackish colure to brick,
while, a lower percentage of iron oxide makes the brick yellow in colure. Iron oxide makes the bricks
hard and strong.

e. Magnesia: Rarely exceeding 1 percent affects the color and makes the brick yellow. A small amount
of magnesia helps to decrease the shrinkage of bricks. This gives a yellow tint to the bricks. But excess
of magnesia is not desirable as it tends to produce the decay of bricks

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 ❖ SILICA

• Percentage: - 50% to 60%

• Function: -

➢ Prevents brick from shrinkage, cracking & warping.

• Effect of Excess: -

➢ Makes brick brittle and useless

❖ ALUMINA

• Percentage: - 20% to 30%

• Function: -

➢ Absorbs water and imparts plasticity to clay so that it can properly molded.

• Effect of Excess: -

➢ Shrink and warp during drying & burning.

❖ LIME

• Percentage: - should not exceed 5%

• Function: -

➢ Binding particles together.

➢ It allows sand to fuse or to melt during burning.

• Effect of Excess: -

➢ Cause to brick melt and loose it's shape.

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 4.4 APPLICATION

Fourth-class bricks are used primarily in applications where high strength, durability, and
aesthetic quality are not critical. Their low cost and ease of production make them suitable for
various non-structural and temporary purposes. Here’s a detailed look at their typical
applications:
Applications of Fourth-Class Bricks:
1. Non-Structural Walls:
o Partitions: Suitable for internal partition walls where load-bearing capacity is not
required. They are often used to divide spaces within a building.
o Interior Base Layers: Used as a base layer for plaster or other finishes in non-load-
bearing walls.
2. Temporary Structures:
o Construction Sites: Commonly used for temporary structures, such as site offices,
storage sheds, and other provisional facilities where cost efficiency is prioritized.
o Event Structures: Employed in the construction of temporary enclosures or walls for
events and exhibitions.
3. Boundary Walls:
o Perimeter Walls: Ideal for boundary walls or fences around properties where the primary
concern is demarcation rather than appearance or strength.
o Garden Walls: Used for constructing garden walls, decorative features, or retaining
walls in landscaping projects where they can be covered or hidden.
4. Utility Structures:
o Septic Tanks and Soak Pits: Used in constructing septic tanks, soak pits, or other utility
structures where high strength is not critical and the primary concern is functionality.
o Drainage Structures: Employed in drainage systems or other utility-related
constructions.
5. Landscaping Features:
o Non-Exposed Walls: Suitable for creating landscaping features or low walls in garden
or park settings where durability and appearance are less critical.
6. Low-Traffic Pavements:
o Walkways: Used in low-traffic areas or pathways where the bricks will not be subjected
to heavy loads or significant wear and tear.
7. Sub-Flooring and Base Layers:
o Support Layers: Used as a base layer under flooring or other construction elements
where structural performance is less critical.
8. Internal Filler:

31
 o In-Fill Walls: Can be used in infill walls or other non-exposed applications where the
bricks will be covered by other materials or finishes.
Key Considerations:
1. Surface Imperfections:
o Fourth-class bricks often have rough, uneven surfaces and may contain cracks or other
defects. These imperfections are usually covered or hidden in their applications.
2. Durability:
o Due to their low durability and high water absorption, fourth-class bricks should not be
used in exposed or high-stress environments. They are better suited for indoor or sheltered
locations.
3. Cost-Effectiveness:
o They provide a cost-effective solution for various construction needs where the strength
and appearance of the brick are secondary concerns.

32
 4.5 COSTING

The cost of fourth-class bricks is generally lower compared to first, second, and third-class bricks
due to their inferior quality and manufacturing processes. Here’s a detailed overview of the
typical costing for fourth-class bricks in India:
Cost of Fourth-Class Bricks:
1. Per Brick:
o Range: Typically between ₹3 to ₹7 per brick.
o Factors Influencing Cost: Prices can vary based on location, local market conditions,
and specific quality of the bricks.
2. Per 1000 Bricks:
o Range: Generally falls between ₹3000 and ₹7000 per thousand bricks.
o Additional Costs: The final cost can be influenced by additional factors such as
transportation, taxes, and delivery charges.
Factors Affecting Cost:
1. Location:
o Urban vs. Rural: Prices may be higher in urban areas due to increased demand and
higher transportation costs. In rural areas, prices may be lower.
2. Quality and Size:
o Variability: There may be slight variations in quality and size, which can affect pricing.
Although fourth-class bricks are typically of lower quality, variations can still influence
cost.
3. Manufacturing Costs:
o Raw Materials: Costs of raw materials and labor affect the price. Fourth-class bricks are
produced with less stringent controls, contributing to lower costs.
4. Transportation:
o Logistics: Delivery costs can vary based on distance from the manufacturing site to the
construction site. Longer distances generally result in higher transportation costs.
5. Local Demand:
o Supply and Demand: Fluctuations in local demand and supply can impact pricing. High
demand or limited supply can drive prices up.
6. Taxes and Fees:
o Regulations: Local taxes, VAT, and other regulatory fees may add to the overall cost.
Example Cost Calculation:
• Cost Per Brick: ₹5
• Cost Per 1000 Bricks: ₹5000
• Additional Costs: Delivery charges (e.g., ₹300) and taxes (e.g., ₹300) might bring the total cost
to approximately ₹5600 to ₹6100 for 1000 bricks.

33
 4.6 SIZE

Fourth-class bricks are often made with less precision compared to higher-grade bricks, resulting
in more variability in size and shape. However, they generally adhere to some standard
dimensions. Here’s a detailed overview of the typical sizes for fourth-class bricks:
Standard Sizes for Fourth-Class Bricks:
1. Common Brick Size:
o Dimensions: 190 mm × 90 mm × 90 mm (length × width × height)
o Description: This is a commonly used size for many types of bricks, including fourth-
class bricks. It is used in various applications but may exhibit more variability in fourth-
class bricks due to less stringent manufacturing controls.
2. Modular Brick Size:
o Dimensions: 200 mm × 100 mm × 75 mm
o Description: This size may be used in some regions, particularly for modular
construction. It is less common for fourth-class bricks but can be found depending on
local practices.
3. Half Brick Size:
o Dimensions: 190 mm × 90 mm × 45 mm
o Description: These thinner bricks are used for specific applications, including partitions
or decorative elements.

34
35