Pavements function is to support increasing loads and resist changes of temperature. The most promising solution to this is modification of bitumen.
The modified bitumen price is higher than normal bitumen, but its portion in the asphalt is only 6%. Practical calculations confirm that the cost of laying 1 kilometer of roadbed with modified bitumen will be 1% more. Considering that it will extend the life of pavement by 2-3 times, there is no doubt in economic potential of this material.
Unmodified bitumen has certain drawbacks, including:
- high thermal responsivity. Bitumen softens at high temperatures and brittles at low temperatures;
- poor mechanical characteristics;
- low elasticity;
- tendency to deteriorate.
These drawbacks initiated a number of studies showing that polymer materials are the best modifiers to improve quality indicators and operating characteristics of bitumen.
Modified bitumen is produced by combining normal bitumen with polymeric compound. This material improves bitumen operating characteristics, elastoplastic characteristics, improve cohesion and adhesion with fillers, increase resistance to changing temperatures and slow deterioration processes.
The level of effectiveness of each of the abovementioned benefits is determined by type of bitumen and polymeric compound and specifics of technologic process.
Bitumen is a colloidal substance with asphaltene molecules forming micellar in a dispersed phase and maltenes and oleoresins in the continuous phase. The specific properties of bitumen are determined by the presence of asphaltenes. The content of oleoresins and maltenes affects the elasticity and plasticity.
Bitumen modifications by polymeric compound with elastic and plastic qualities results in getting a polymer-bitumen binder, or polymer modified bitumen (PMB). PMB is a new material, that extends the life of road surfaces. Compared to regular bitumen, the modified product has a whole set of new qualities: fracture resistance, elasticity, increased strength, extended plasticity.
Polymer Modified Bitumen can be produced at asphalt plants, as well as with privately owned equipment.
Regardless of the method of modified bitumen production, the main part of the plant is always a colloidal mill. Milling of polymeric compounds helps to increase contact area of blending components while accelerating swelling and dissolving processes.
During the production of PMB colloidal mill reduces size of polymeric particles to molecular level and distributes them in bitumen – forming polymer network.
GlobeCore supplies the world market with high-tech equipment for production of polymer modified bitumen. The manufactured product has the highest quality and can be successfully used to solve current problems of road construction and repairing.
GlobeCore design-engineering department developed a colloidal mill, specifically designed for production of modified bitumen.