[Chemical Knowledge]：The nature, use, upstream and downstream raw materials, storage methods of asphalt, what are the properties of asphalt

Asphalt properties

Asphalt is a black or dark brown viscous liquid or solid, mainly composed of hydrocarbons and their non-metallic derivatives. Its viscosity and hardness change with the change of temperature, and it has good adhesion and water resistance. According to its source and processing method, asphalt can be divided into natural asphalt and petroleum asphalt. Natural bitumen mostly exists in asphalt lakes and tar sands, while petroleum bitumen is the residue of crude oil distillation.

Bitumen chemical composition

The main components of asphalt are aromatic and naphthenic compounds, and contain a small amount of sulfur, nitrogen, oxygen and other non-metallic elements. Its molecular structure is complex, composed of a variety of different molecular weight components. According to different uses and requirements, the chemical composition and physical properties of asphalt can be adjusted by different processing techniques.

Asphalt physical properties

Physical properties of asphalt include density, softening point, ductility, viscosity, and aging characteristics. The density is typically between 1.0 and 1.2 grams per cubic centimeter. The softening point is the temperature at which asphalt changes from solid to liquid, usually between 50 and 100 degrees Celsius. The ductility and viscosity of asphalt determine its applicability and effect in the construction process. Aging characteristics refer to the changes in the performance of asphalt under long-term exposure to environmental conditions such as sunlight, air, and water.

Asphalt use

Asphalt is widely used in construction, roads, roofs, waterproofing and anti-corrosion fields. The most common use is paving roads and highways, followed by making roofing materials. Due to its excellent waterproof and bonding properties, asphalt is also used in the manufacture of waterproof materials, anti-corrosion coatings, sealing materials, etc. In the industrial field, asphalt can also be used as a moisture-proof and anti-corrosion coating material.

Application of Asphalt in Road Construction

In road construction, asphalt is mainly used for paving roads, and its function is to provide a smooth, durable, waterproof and skid-resistant road surface. According to different road requirements, asphalt can be mixed with stone to make asphalt concrete for different levels of pavement structure. Asphalt used in pavement is usually required to have a high softening point and good wear resistance to ensure the service life and safety of the road.

Asphalt for roofing and waterproofing applications

In the construction field, asphalt is often used to make roof coils and waterproof coatings. Because of its good waterproof performance and convenient construction, asphalt membrane is widely used in waterproof treatment of roof and underground engineering. Asphalt waterproof coating is suitable for waterproof treatment of various complex structures, which can effectively prevent moisture penetration and material aging.

Asphalt upstream and downstream raw materials

The production of bitumen mainly depends on crude oil, and its upstream raw materials include various types of crude oil, especially heavy crude oil. Downstream products cover a variety of asphalt products, such as road asphalt, construction asphalt, waterproof materials, sealing materials, etc. The nature and quality of crude oil directly affect the performance and use of asphalt, so the selection of crude oil and processing technology are very important.

Asphalt production process

The production process of asphalt mainly includes crude oil distillation, catalytic cracking, oxidation and modification. Crude oil distillation is the basic process for the production of asphalt, through the atmospheric and vacuum distillation of crude oil, to obtain different boiling point range of fractions, the final residue is asphalt. In order to improve the performance of asphalt, it can also be catalytic cracking, oxidation and modification treatment, so that it has better adhesion, durability and water resistance.

Asphalt storage method

The storage of asphalt requires special equipment and environment to prevent its deterioration and performance degradation. The container for storing asphalt is usually a metal storage tank, the inner wall is coated with anti-corrosion materials, and is equipped with heating and stirring devices to maintain the uniformity and fluidity of the asphalt. Storage tanks should be installed in a well-ventilated place away from fire sources, and regularly inspected and maintained to prevent leakage and fire accidents.

Asphalt Transportation

The transportation of asphalt also requires special equipment and methods. Because asphalt is a solid or high viscosity liquid at room temperature, it needs to maintain a certain temperature during transportation to ensure its fluidity. Common modes of transportation include heated tankers, heated ships, and pipeline transportation. During transportation, attention should be paid to prevent the cooling and solidification of asphalt, and fire prevention and leakage prevention measures should be taken to ensure the safety of transportation.

Asphalt environmental impact

Asphalt in the production, storage, transportation and use of the process may cause a certain impact on the environment. The main environmental problems include the discharge of volatile organic compounds, the treatment of waste water and waste gas, and the recovery and utilization of waste asphalt. In order to reduce environmental pollution, it is necessary to adopt advanced production technology and environmental protection measures, such as waste gas purification, waste water treatment and waste recycling.

Asphalt Future Trends

With the progress of science and technology and the improvement of environmental protection requirements, the asphalt industry is also constantly innovating and developing. In the future, the production and use of asphalt will pay more attention to environmental protection and sustainable development. The development and application of new asphalt materials, such as high-performance modified asphalt, cold-mixed asphalt and renewable asphalt, will further improve the performance and environmental protection of asphalt. Waste asphalt recycling and reuse technology will also be widely used to promote the green development of the asphalt industry.

Conclusion

As an important industrial material, asphalt has unique physical and chemical properties, and is widely used in road construction, building waterproofing and corrosion protection. Its upstream raw material is mainly crude oil, and the production process involves distillation, catalytic cracking and modification. In order to ensure the quality and performance of asphalt, special equipment and measures are required during storage and transportation. In the future, with the progress of science and technology and the enhancement of environmental awareness, the asphalt industry will develop in a more environmentally friendly and sustainable direction.