Modified asphalt is a product that modifies asphalt by physical or chemical methods, the purpose of which is to improve certain properties of asphalt, such as softening point, adhesion, heat resistance, and oxidation resistance. The production principle of modified asphalt mainly involves the following aspects:
1. Heat treatment: By heating asphalt, the high molecular weight compounds in it can be pyrolyzed to generate lower molecular weight compounds, thereby improving the fluidity and cohesiveness of asphalt. At the same time, heat treatment can also promote the polymerization of aromatic compounds in asphalt to form a larger molecular structure, and improve the softening point and thermal stability of asphalt.
Oxidation: Through oxidation treatment, the chemical structure of asphalt can be changed, and its heat resistance and oxidation resistance can be improved. During the oxidation process, the unsaturated bonds in the bitumen are oxidized to form stable ketones, carboxylic acids, and aromatic compounds that have high thermal stability and weather resistance.
3. Add modifiers: adding specific modifiers to asphalt, such as polymers, resins, rubber, etc., can significantly change the properties of asphalt. For example, the addition of rubber can improve the elasticity and crack resistance of asphalt, while the addition of resin can improve the adhesion and heat resistance of asphalt.
4. Catalytic modification: In the process of upgrading asphalt, the use of catalyst can accelerate the chemical reaction and improve the efficiency of upgrading. Catalysts can be metallic, acidic, or basic, and they can facilitate molecular rearrangement, cracking, and polymerization reactions in asphalt.
5. Control of pressure and temperature: In the process of upgrading, the molecular structure and properties of asphalt can be adjusted by controlling pressure and temperature. Higher pressures and temperatures help to promote chemical reactions in bitumen to form a more stable molecular structure.
6. Solvent extraction: In some cases, specific components in asphalt can be separated and purified by solvent extraction, thereby changing the composition and properties of asphalt.
The production process of modified asphalt requires precise control of various process parameters to ensure that the performance of the final product meets the specific application requirements. By modifying the asphalt, it can perform better in a variety of industrial applications, such as as electrode binders, road pavement materials, building materials, etc.