Brick- #Building Materials

Brick

1. 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.

2. Core Concepts
3. 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

1. Manufacturing Process of Bricks

This is a very important exam topic.

1. Preparation of Clay

Steps:

1. Unsoiling – Removing top organic soil
2. Digging – Taking clay from ground
3. Cleaning – Removing stones, roots
4. Weathering – Exposing clay to air
5. Blending – Mixing with sand, ash
6. Tempering – Adding water and mixing

2. Moulding of Bricks

Two methods:

• Hand moulding
• Machine moulding

Bricks are given standard shape and size.

3. Drying of Bricks

• Removes moisture
• Prevents cracking during burning
• Takes about 7–14 days

4. Burning of Bricks

Burning is done in:

• Clamp
• Kiln (most common)

Temperature: 900°C – 1200°C

Burning gives:

• Strength
• Hardness
• Durability

1. Classification of Bricks
2. Unburnt Bricks

• Dried in sun
• Low strength
• Used for temporary works

2. 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

1. Standard Size of Brick

Standard modular brick size:

190 mm × 90 mm × 90 mm

With mortar:

200 mm × 100 mm × 100 mm

1. 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

3. 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

4. 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.

5. 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.

6. Multiple Choice Questions (MCQs)
7. Bricks are made from:
8. Cement
   B. Clay
   C. Lime
   D. Stone

Answer: B

Explanation: Bricks are manufactured by moulding and burning clay.

2. Which ingredient gives red colour to bricks?
3. Lime
   B. Silica
   C. Iron oxide
   D. Alumina

Answer: C

Explanation: Iron oxide gives red colour and strength.

3. Standard size of modular brick is:
4. 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.

4. Which bricks are used for temporary works?
5. First class
   B. Second class
   C. Third class
   D. Fourth class

Answer: C

Explanation: Third class bricks are under-burnt and weak.

5. Burning of bricks is done at:
6. 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.

6. Water absorption of good brick should be less than:
7. 10%
   B. 15%
   C. 20%
   D. 25%

Answer: C

Explanation: IS code permits maximum 20%.

7. Over-burnt bricks are called:
8. First class
   B. Second class
   C. Third class
   D. Fourth class

Answer: D

Explanation: Fourth class bricks are over-burnt and brittle.

8. Which process removes organic matter from clay?
9. Digging
   B. Unsoiling
   C. Tempering
   D. Moulding

Answer: B

Explanation: Unsoiling removes top soil containing organic matter.

9. Number of bricks in 1 m³ brickwork is approximately:
10. 400
    B. 450
    C. 500
    D. 550

Answer: C

Explanation: Standard calculation gives 500 bricks.

10. Which test checks salt content in bricks?
11. Hardness test
    B. Compressive strength test
    C. Efflorescence test
    D. Water absorption test

Answer: C

Explanation: Efflorescence test detects white salt deposits.