Brick
- Introduction
A brick is a small rectangular masonry unit made by molding clay and hardening it by burning in a kiln.
Bricks are one of the oldest and most commonly used building materials for constructing walls, pavements, and buildings.
👉 In simple words: Brick is an artificially manufactured stone used in masonry construction.
- Core Concepts
- Ingredients of Good Brick Earth
Good brick earth should contain:
| Ingredient | Function |
| Alumina | Provides plasticity |
| Silica | Prevents cracking & shrinkage |
| Lime | Helps in fusion |
| Iron oxide | Gives strength & red color |
| Magnesia | Reduces shrinkage |
- Manufacturing Process of Bricks
This is a very important exam topic.
- Preparation of Clay
Steps:
- Unsoiling – Removing top organic soil
- Digging – Taking clay from ground
- Cleaning – Removing stones, roots
- Weathering – Exposing clay to air
- Blending – Mixing with sand, ash
- Tempering – Adding water and mixing
- Moulding of Bricks
Two methods:
- Hand moulding
- Machine moulding
Bricks are given standard shape and size.
- Drying of Bricks
- Removes moisture
- Prevents cracking during burning
- Takes about 7–14 days
- Burning of Bricks
Burning is done in:
- Clamp
- Kiln (most common)
Temperature: 900°C – 1200°C
Burning gives:
- Strength
- Hardness
- Durability
- Classification of Bricks
- Unburnt Bricks
- Dried in sun
- Low strength
- Used for temporary works
- Burnt Bricks
(a) First Class Bricks
- Well-burnt
- Uniform shape
- Used for important structures
(b) Second Class Bricks
- Slightly irregular
- Used for plastered walls
(c) Third Class Bricks
- Under-burnt
- Low strength
- Used for temporary works
(d) Fourth Class Bricks
- Over-burnt
- Brittle
- Used as road ballast
- Standard Size of Brick
Standard modular brick size:
190 mm × 90 mm × 90 mm
With mortar:
200 mm × 100 mm × 100 mm
- Tests on Bricks
| Test | Purpose |
| Compressive strength test | Check load capacity |
| Water absorption test | Check durability |
| Efflorescence test | Check salt content |
| Hardness test | Scratch resistance |
- Step-by-Step Practical Examples
Example 1: Number of Bricks in 1 m³ of Brickwork
Standard brick with mortar = 200 × 100 × 100 mm
Step 1: Convert to meters
= 0.2 × 0.1 × 0.1 m
Step 2: Volume of one brick
= 0.002 m³
Step 3: Number of bricks
➡ 500 bricks are required for 1 m³ brickwork
Example 2: Checking Suitability of a Brick
A brick absorbs 18% water.
Step 1: Standard limit
Water absorption should be less than 20%
Step 2: Compare
18% < 20%
➡ Brick is suitable for construction
- Visual Aid Description (Diagram / Flowchart)
Title: Manufacturing Process of Bricks
Flowchart:
Clay → Preparation → Moulding → Drying → Burning → Finished Bricks
Each step shown in boxes connected by arrows.
This helps students remember the sequence easily in exams.
- Exam Focus: Must-Know Points ⭐
- Brick is an artificial masonry unit made from burnt clay.
- Standard brick size = 190 × 90 × 90 mm.
- Burning temperature = 900°C – 1200°C.
- First class bricks are used for important structures.
- 500 bricks are required for 1 m³ brickwork.
- Multiple Choice Questions (MCQs)
- Bricks are made from:
- Cement
B. Clay
C. Lime
D. Stone
Answer: B
Explanation: Bricks are manufactured by moulding and burning clay.
- Which ingredient gives red colour to bricks?
- Lime
B. Silica
C. Iron oxide
D. Alumina
Answer: C
Explanation: Iron oxide gives red colour and strength.
- Standard size of modular brick is:
- 200 × 100 × 100 mm
B. 190 × 90 × 90 mm
C. 180 × 80 × 80 mm
D. 210 × 110 × 110 mm
Answer: B
Explanation: Actual brick size without mortar is 190 × 90 × 90 mm.
- Which bricks are used for temporary works?
- First class
B. Second class
C. Third class
D. Fourth class
Answer: C
Explanation: Third class bricks are under-burnt and weak.
- Burning of bricks is done at:
- 200°C – 400°C
B. 500°C – 700°C
C. 900°C – 1200°C
D. 1500°C – 1700°C
Answer: C
Explanation: Proper strength is obtained between 900°C – 1200°C.
- Water absorption of good brick should be less than:
- 10%
B. 15%
C. 20%
D. 25%
Answer: C
Explanation: IS code permits maximum 20%.
- Over-burnt bricks are called:
- First class
B. Second class
C. Third class
D. Fourth class
Answer: D
Explanation: Fourth class bricks are over-burnt and brittle.
- Which process removes organic matter from clay?
- Digging
B. Unsoiling
C. Tempering
D. Moulding
Answer: B
Explanation: Unsoiling removes top soil containing organic matter.
- Number of bricks in 1 m³ brickwork is approximately:
- 400
B. 450
C. 500
D. 550
Answer: C
Explanation: Standard calculation gives 500 bricks.
- Which test checks salt content in bricks?
- Hardness test
B. Compressive strength test
C. Efflorescence test
D. Water absorption test
Answer: C
Explanation: Efflorescence test detects white salt deposits.
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