April 13, 2024
Asphalt

The versatile construction material – Asphalt

Asphalt is one of the most commonly used construction materials all over the world. From roads and highways to playgrounds and sports infrastructure, asphalt has a wide range of applications

What is Asphalt?

Asphalt, also known as bitumen, is a sticky, black and highly viscous liquid or semi-solid form of petroleum. It is made from the heavier fractions of crude oil that are left behind in the distillation process. Asphalt is thermoplastic and at higher temperatures can be melted and reshaped. When cooled, it becomes solid and keeps its shape.

Composition and Production

Asphalt is primarily composed of complex organic compounds such as hydrocarbons, with a small amount of inorganic materials. During production, crude oil is distilled in a refinery to separate lighter hydrocarbon fractions like gasoline from heavier residual oil. This residual oil is then further processed to obtain asphalt. Asphalt cement, the most common type, contains about 4-8% water and 92-96% bitumen. It is produced either by air blowing or oxidation to meet various standards and specifications.

Uses in Road Construction

Roads and highways are the largest application area for asphalt globally. Different processes are involved to use asphalt for roads:

– Asphalt Mixing: Asphalt cement is blended with aggregates like sand and gravel at hot mix plants to create asphalt concrete. This mix can be easily laid down and compacted.

– Paving: The hot asphalt concrete mix is laid down in layers on the prepared road base using paving equipment. Each layer is compacted to desired density.

– Surfacing and sealing: Thin applications of asphalt emulsion are used for surface sealing to protect and bind the layers. Asphalt overlays can also refurbish aging roads.

– Other uses: Asphalt is used for pavements in parking lots, driveways, airports, and bike/walking paths due to its durability in traffic loading and varying climatic conditions.

Advantages in Road Construction

Some key advantages of using asphalt in road construction include:

– Cost effectiveness: Asphalt roads have lower initial construction cost compared to other paving options. Maintenance cost is also economical.

– Durability: Properly laid asphalt roads can last over 20 years with routine maintenance, depending on traffic loads and weathering.

– Smoother ride: Asphalt concrete provides better elasticity and distributes loads well for a quieter and smoother driving experience.

– Recyclability: Used asphalt rubble can be reused while repaving up to 100% of the material, reducing waste.

Other Applications

Apart from roads, asphalt also finds many other uses across various industries:

Roofing:
– Asphalt roofing shingles and roll roofing are majorly used roofing materials globally. Their durability and waterproof ability makes them suitable for rooftops.

Recreation:
– Asphalt is ideal for building basketball courts, tennis courts, jogging tracks etc. due to required hardness and load-bearing capability.

Waterproofing:
– Asphalt felts are used extensively for below-grade waterproofing and damp proofing of foundations.

Industrial Usage:
– Asphalt coating of pipes, tanks protects against corrosion. It is a binder in products like carpet backing, wallpaper, paints, etc.

Asphalt is a versatile construction substance that caters to diverse infrastructure needs across the world. Modern life would not be possible without the continual usage of asphalt in developing robust roads, buildings, and various other construction applications. Advanced technologies also enable innovating with asphalt for sustainability. Asphalt certainly remains a cornerstone material for the growth of urbanization and transportation worldwide.

*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it