3. Bricks in Civil Engineering

 

Bricks in Civil Engineering

Bricks are one of the oldest and most widely used building materials in civil engineering, valued for their durability, compressive strength, and versatility in construction. They are primarily made from clay (fired or sun-dried) and used for walls, partitions, foundations, pavements, and structural elements like arches or retaining walls.

Standard Brick Dimensions

Brick sizes vary by country, but include mortar joints (typically 10 mm) for modular construction:

• India: Actual size 190 × 90 × 90 mm; with mortar ~200 × 100 × 100 mm.
• USA: 203 × 92 × 57 mm (8 × 3⅝ × 2¼ inches).
• UK: 215 × 102.5 × 65 mm.
• Global common (including Nepal/Australia variations): Often around 230 × 110 × 75 mm.

The length is typically twice the width plus one joint for efficient bonding.

Types of Bricks

Bricks are classified by material, quality, manufacturing, and use:

Type	Description	Common Uses	Key Properties
Burnt Clay Bricks	Fired in kilns; most common. Subclasses: First-class (uniform, strong), Second-class (minor defects), Third-class (rough).	Load-bearing walls, exposed surfaces	High strength, low absorption
Engineering Bricks	Dense, low porosity; Class A/B/C (A strongest).	Sewers, manholes, retaining walls, damp-proof courses	High compressive strength (>125 N/mm² for Class A), chemical/acid resistance
Fly Ash Bricks	Made from fly ash, cement, sand; eco-friendly.	General construction, lightweight panels	Good strength, lower weight
Concrete Bricks	Cement-based; often hollow.	Partitions, heavy-load structures	High durability, fire resistance
Fire/Refractory Bricks	Heat-resistant materials.	Chimneys, furnaces	Withstands high temperatures
Sun-Dried Bricks	Air-dried clay; low strength.	Temporary or low-load structures	Cheap but not durable

Properties of Good Bricks

• Compressive Strength: Minimum 3.5–10 N/mm² (higher for engineering bricks).
• Water Absorption: <20% for good quality; <4.5% for engineering.
• Shape & Size: Uniform, sharp edges, no cracks.
• Color & Texture: Uniform red/yellow, pleasant ringing sound when struck.
• Efflorescence: Minimal (no white salts on surface).

Brick Masonry Details

Brick masonry involves laying bricks in systematic patterns (bonds) with mortar (cement/sand or lime-based) to form solid, load-bearing structures.

Common Brick Bonds (patterns for strength and aesthetics):

• Stretcher Bond: Bricks laid lengthwise; simplest, for half-brick walls.
• Header Bond: Bricks laid with ends exposed; for full-brick walls.
• English Bond: Alternating courses of stretchers and headers; very strong.
• Flemish Bond: Headers and stretchers in each course; decorative and strong.
• Garden Wall Bond: Variation for visibility on both sides.

Key Construction Details:

• Mortar Joints: 10–12 mm thick; types include concave, flush, or weathered.
• Damp-Proof Course (DPC): Engineering bricks or bitumen layer below ground level.
• Weep Holes: Small openings for drainage in cavity walls.
• Sills & Copings: Sloped brick details at windows/base to shed water.
• Corbels & Soldier Courses: Projecting or vertical bricks for decoration/support.

Brick masonry provides excellent fire resistance, thermal mass, and longevity but requires proper detailing to prevent water penetration and cracking.

For visual examples, here are common types and masonry patterns:

Bricks in Civil Engineering: Key Details

Bricks are fundamental building units in civil engineering, typically rectangular blocks made from clay, concrete, or other materials. They are used for constructing walls, foundations, pavements, arches, and more due to their compressive strength, durability, and fire resistance.

Types of Bricks

Standard Dimensions

Brick Masonry Bonds/Patterns

Common bonds ensure structural integrity and aesthetics (e.g., English for strength, Flemish for decoration, Stretcher for simplicity).

Construction Details

Typical cross-sections and elements like reinforced walls or cavity construction.

These details cover essential aspects for civil engineering applications, including quality control, bonding for load distribution, and waterproofing features like weep holes in cavity walls.