Petroleum Bitumen or simply Bitumen is a petroleum derivative commonly referred to as asphalt, is a black, viscous, and sticky liquid or semi-solid. Bitumen is derived from crude oil through a process called fractional distillation. It is the heaviest fraction separated from the crude oil during refining. It is an essential feature of many infrastructure and construction projects, especially those involving road paving and waterproofing
Key elements of bitumen are as follows:
Components:
It consists of a complex mixture of hydrocarbons, with high molecular weight and a substantial proportion of carbon and hydrogen.
Types of Bitumen:
- Penetration Grade Bitumen: Classified based on penetration value, which measures the hardness of the bitumen.
- Performance Grade Bitumen: Characterized by specific performance properties at different temperatures.
- Viscosity Grade Bitumen: Categorized based on viscosity characteristics at elevated temperatures.
- Cutback Bitumen: Bitumen combined with a solvent for ease of application.
- Emulsion Bitumen: Bitumen dispersed in water with the help of an emulsifying agent.
Common Applications:
- Road Construction: Bitumen is a primary binder used in asphalt for road surfaces, providing durability and resistance to weather conditions.
- Roofing: Used as a waterproofing material for roofs.
- Pavement Sealants: Applied to pavements to protect against wear and deterioration.
- Waterproofing: Used in the construction industry to create water-resistant layers.
Properties:
- Viscosity: Bitumen's viscosity is temperature-dependent. It becomes more fluid at higher temperatures and solidifies at lower temperatures.
- Adhesive Properties: Bitumen has excellent adhesive properties, allowing it to bind with aggregates in asphalt mixes.
- Impermeability: Bitumen is impermeable to water, making it an effective waterproofer.
Transport and Handling:
Due to its high viscosity, bitumen is often heated during transport and handling to make it more workable. Bitumen undergoes changes in viscosity with temperature, which can affect its handling and application.
Standards and Specifications:
Various standards and specifications exist for different grades of bitumen, ensuring quality and performance in specific applications.