Bricks are classified as either sun dried/katcha bricks or burnt/pacca bricks. Sun dried bricks are made through natural drying and used for temporary structures due to lack of durability when wet. Burnt bricks are fired, making them hard, strong, and durable for permanent construction. Burnt bricks are further classified into four classes based on their quality - first class bricks are well-burnt without cracks while overburnt/jhama bricks are misshapen and used for aggregates. A variety of tests are used to determine brick suitability for construction purposes.

1. CLASSFICATION OF BRICKS
• Bricks are broadly classified into two
categories.
1.SUN DRIED OR KATCHA BRICKS
2.BURNT OR PACCA BRICKS

2. 1.SUN dried or katcha bricks
•Production Process: Sun dried bricks are made by molding clay and allowing
them to dry naturally in the sun. These bricks are not burnt in camp or kiln.
• Usage: Suited for temporary and cost-effective constructions.
•Limitation: Unsuitable for areas with heavy rainfall due to lack of durability. Avoid
using these bricks in places exposed to heavy rains.

3. 2.Burnt or Pacca bricks:
Production Process :Bricks formed by molding, drying, and then
burning in a clamp or kiln.
Characteristics: Hard, strong, and durable.
High-quality due to firing process.
Uniform shape and size
Uses: Ideal for permanent construction.
Used in load-bearing structures.
Provides structural stability.
These bricks are also further classified into four types.

4. Classification of Burnt and Pacca Bricks
1. First Class Bricks
2. Second Class Bricks
3. Third Class Bricks
4. Overburnt or jhama Bricks

5. FIRST-CLASS BRICKS
Well burnt and regular in shape
Smooth, clean surface without cracks
Water absorption ≤ 1/6 of its weight
Uniform compact structure
Metallic ringing when struck together
Doesn't break when dropped from a height of 1 to 2 meter
Specific gravity of 1.8
Cannot be marked with fingernails Minimum
crushing strength of 10.5 N/mm²
• These bricks are moulded into table-
moulding and burnt in large kilns.
Characteristics of First-Class Bricks:

6. USES
• In R.B Work.
• For flooring and walling purposes.
• As ballast for R.C work.
• Shaped bricks for carvings, arches .

7. Second-Class Bricks:
• These bricks are ground-moulded and they burnt in kilns.
Characteristics of Second class Bricks
 Irregular shape & size
 Rough surface
 Edges not well-defined
 Presence of lumps & cracks
 Non-uniform color
Fine, compact, uniform texture
Produces ringing sound when struck
 Minimum crushing strength: 7 N/mm²

8. Uses:
• Low load bearing walls in gardens
or yards
• Building walls that don’t carry heavy
weight.
• Creating inner walls in double-
layer walls
• Making temporary structures

9. Third Class Bricks -
Bricks that are under burnt and lack
uniformity in shape and size are
commonly known as third class
or pilla bricks.
Characteristics:
• Light yellowish color
.
• Rough and irregular surface.
• Not well-burnt.
• Soft texture due to incomplete firing.
• When struck, emits a dull sound.
• Associated with flaws and cracks.
• Edges are irregular and inconsistent.
Used in inferior and temporary constructions.

10. These are overburnt bricks with irregular shape and dark
Colour .
Characteristics:
1. Overburnt, vitrified, and distorted appearance.
2. Irregular shape and varying sizes, often found in lumps.
3. Dark color in lumps.
4. Hard and strong texture.
5. Produces a metallic ringing sound.
Uses:
o Utilized as aggregates in concrete production.
o Used in constructing foundations, floors, etc.
o Employed as road metal for soling coat in road
construction.
OVERBURNT OR JHAMA BRICKS

11. TESTS FOR BRICKS
In order to find out the suitability of a brick
for the construction work, it
is generally subjected to the following
tests:
 Water absorption test
 Efflorescence test
 Compressive strength test
 Structure test
 Soundness test
 Shape and size test
 Hardness test

12. Water absorption test:
 Weigh the dry brick.
 Immerse it in water for 16 hours.
 Re-weigh the brick.
 Calculate the weight difference to find water absorption.
 Ensure the water absorption does not exceed 20% of the dry brick's weight.
Soundness Test:
 Gently strike two bricks together
.
 Bricks should not break and should create a clear ringing sound.
Hardness Test:
Ø Scratch brick surface with a fingernail.
Ø No impression left indicates sufficient hardness.

13. Efflorescence Test
Purpose: Identify presence and severity of soluble salt in bricks causing efflorescence.
Procedure:
1. Immerse brick in water for 24 hours.
2. Remove and allow brick to dry in shade.
Observations:
 No grey/white deposits ➔ No soluble salts.
 <10% surface covered ➔ Absence of soluble salts.
 About 10% coverage ➔ Slight efflorescence.
 About 50% coverage ➔ Moderate efflorescence.
 >50% coverage ➔ Heavy, serious efflorescence.
To Be Continued……