Tar, Bitumen and Asphalt: Properties, Applications and Uses

Tar, Bitumen and Asphalt: Properties, Applications and Uses

Tar, bitumen, and asphalt are important construction materials widely used in civil engineering, especially in road construction and waterproofing works. These materials are known for their binding properties, water resistance, and durability. In the ITI Draughtsman Civil trade, understanding these materials is essential for preparing accurate drawings and specifications related to road works and infrastructure projects.

Although these materials are similar in appearance, they differ in origin, composition, and specific uses. Each material plays a significant role in construction depending on the requirement.

Tar

Tar is a black, viscous liquid obtained from the destructive distillation of organic materials such as coal, wood, or peat. It was widely used in the past for road construction but has now been largely replaced by bitumen due to environmental concerns.

Properties of Tar:

• Highly adhesive in nature
• Waterproof and resistant to moisture
• Good binding property
• Produces strong odor and fumes

Applications and Uses:

• Road construction (earlier use)
• Waterproofing of roofs
• Protective coatings

Bitumen

Bitumen is a black, sticky, and highly viscous material obtained from petroleum. It is the most commonly used binding material in road construction today.

Properties of Bitumen:

• Excellent binding property
• Waterproof and weather resistant
• Highly durable
• Thermoplastic in nature (softens on heating and hardens on cooling)

Applications and Uses:

• Road construction and surfacing
• Waterproofing works
• Damp-proofing in buildings
• Sealing cracks and joints

Asphalt

Asphalt is a mixture of bitumen and aggregates such as sand, gravel, or crushed stone. It is widely used in the construction of roads, pavements, and airfields.

Properties of Asphalt:

• Strong and durable
• Smooth surface finish
• Flexible and resistant to cracking
• Good load-bearing capacity

Applications and Uses:

• Roads and highways
• Airport runways
• Parking areas and pavements

Difference Between Tar, Bitumen and Asphalt

• Tar: Derived from coal or organic materials
• Bitumen: Derived from petroleum
• Asphalt: Mixture of bitumen and aggregates

Bitumen is preferred over tar due to its better performance and lower environmental impact, while asphalt is used as a finished road material.

Advantages of These Materials

• Excellent waterproofing properties
• Strong binding capability
• Durable and long-lasting
• Provides smooth and safe road surfaces

Limitations

• Temperature sensitive (softens in heat)
• Requires proper handling and application
• Environmental concerns in case of tar

Applications in Civil Engineering

These materials are widely used in infrastructure development:

• Road construction and maintenance
• Waterproofing of buildings
• Industrial flooring
• Protective coatings

Importance for Draughtsman Civil Trade

Knowledge of tar, bitumen, and asphalt helps draughtsmen in preparing accurate road drawings and specifications. It also helps in understanding material selection and application in different construction works.

Conclusion

Tar, bitumen, and asphalt are essential materials in civil engineering, particularly in road construction and waterproofing. Each material has unique properties and applications that make it suitable for specific uses.

Understanding these materials is important for students of the ITI Draughtsman Civil trade, as it enables them to design and plan construction projects effectively using modern materials and techniques.