What you know about bitumen and asphalt additives?
Today, in addition to materials and components of asphalt mixtures (bitumen, stone materials and mineral fillers), bitumen and asphalt additives are also used. Bitumen and asphalt additives, which include a wide range of organic, mineral, natural and industrial materials, in order to improve physical properties, reduce defects or change some mechanical properties of bitumen and asphalt mixtures prepared with bitumen. The use of bitumen and asphalt additives in asphalt operations is increasingly developing. The first bitumen and asphalt additive was used to improve the properties of bitumen, which was used more than 100 years ago by a chemist named Kadenberg. In 1898, this chemist patented the process of preparing bitumen by adding rubber to his name, so that he could control some of the physical properties of bitumen using the elastic properties of natural rubber. To discover, produce and use bitumen and asphalt additives and suitable substitutes for bitumen and preparation of modified bitumen’s, the following technical, executive and economic needs are required:
- Solve specific problems of asphalt procedures
- Saving energy and materials (in the method of recycling old asphalt mixtures and using alternative materials with bitumen)
- Dealing with environmental conditions, atmospheric-climatic
- Providing executive facilities
The above is achieved by modifying the properties of bitumen and asphalt mixtures in the following cases
- Increasing the plasticity of bitumen by creating a greater distance between the temperature of the bitumen break point (Fras test) and the bitumen softening point (ring and ball test)
- Reducing the thermal sensitivity of bitumen to increasing the hardness at high temperatures to prevent the formation of grooves and displacement of the asphalt surface and reducing the hardness at low temperatures to prevent cracking in cold and icy weather, which have two properties simultaneously in bitumen and mixtures Asphalt is provided.
- Increased bitumen adhesion at the maximum service temperature, which is normally 60 ° C
- Improving the elastic property of bitumen, which increases its resistance to fatigue.
- Provide more and more durable adhesion between bitumen and aggregates in the presence of water at low temperatures
Classification of additives
- Mineral powders (fillers): lime, cement, carbon dioxide, etc.
- Alternatives that can be used in large quantities instead of bitumen, such as lignites, sulfur, etc
- Elastomers, natural latex, synthetic latex, such as styrene butadiene (SB) or block copolymer bonded copolymers. Block copolymers such as styrene, butadiene, styrene or rubber recovered from worn tires and so on.
- Plastics, polyethylene, polypropylene, ethylene vinyl acetate EVA, polyvinyl caride or PVC
- Different combinations of elastomers and plastics of the above three and four rows
- Fillers, fibers, such as rock wool, polyester, asbestos, etc.
- Oxidizers, manganese and other metal salts and so on
- Antioxidants, such as tin compounds, carbon, calcium salts and so on
- Natural bitumens, such as Trinidad, Bermuda and natural bitumens
- Hydrocarbons: Aromatic compounds are used in asphalt recycling.
Today, the group of elastomers and plastics in the field of additives and bitumen modifiers have many uses and applications in asphalt operations. German Ivanic anti-stripper additive under the brand name TEGO Addibit L300 is used to ensure the moisture durability of asphalt. Vietnammer polymer from the German company Ivanik is used in combination with rubber powder. Vestaplast polymer from the German company Ivanik increases the performance range of bitumen at high and low temperatures. PDF emulsifier has excellent performance for preparing emulsion bitumen.Emulsion bitumen concentrator (Thickner) of the German company Ivanik is widely used to improve the concentration of emulsion bitumen. Vestavox improves PG bitumen with better performance than Sasubit.