The history of bitumen starts in ancient times. The first mention of bitumen was in the late Stone Age. But at that time it had another name – earth resin. It was used for encapsulation of crockery, creating of mosaic (for materials fixation) and as an isolation layer in building constructions. In ancient Egypt bitumen was used for embalming of dead bodies.
So, what kind of substance is it? Bitumen is a mixture of hydrocarbons and their derivatives, containing sulfur, nitrogen, oxygen and metals. Bitumen looks like resin, because basically it has a solid structure. No wonder that word-by-word translation of the term “bitumen” sounds as “fossil resin” or “oil”.
Bitumen qualities do not change under the effect of moisture. This is its distinguishing feature.
What kinds of bitumen exist?
Bitumen can be natural and synthetic. Natural bitumen is extracted from the earth. Synthetic bitumen is produced in industrial way by processing other materials.
Natural bitumen falls into the following classes: asphalt, asphaltite, maltha, kerite and anthraxolite. These materials are produced either in special mines, or by the field developing in open pits.
Synthetic bitumen is basically the bottom product which is generated after crude oil, pit coal or shale recycling. Chemical compositions of synthetic and natural bitumen are identical.
How is bitumen produced and industrially processed?
Let’s have a look at methods of gaining bitumen. A mine or an open pit is used for extraction of bituminous rock. After that, bituminous rock is split into organic and mineral parts. Then it is delivered for after-treatment, because natural material is not the end product.
Synthetic bitumen is produced from fuel oil or tar through following processes:
- vacuum distillation;
- solvent deasphalting;
- oxidizing processes.
Above mentioned processes are applied either separately or in combination.
Important characteristics of bitumen:
The most important qualities of bitumen are:
- adhesive properties;
- flash point;
- brittleness temperature;
- softening point;
When environment temperature is increasing, bitumen viscosity is getting lower. On the contrary, when the temperature is getting lower, viscosity is sharply increasing. At subzero temperatures bitumen becomes a brittle substance.
Bitumen plasticity depends on the amount of oils it contains and environment temperature.
Softening point defines brittleness temperature of bitumen. Softening temperature usually ranges from +20 ºС to +95 ºС.
If brittleness temperature of bitumen is low it testifies of its frost resistance and high quality.
An average flash temperature of bitumen exceeds 200ºС. It is a quite important value, it helps to estimate an inflammability degree of material during its heating.
Adhesion is also quite an important feature. It characterizes bitumen ability to stick to different surfaces.
Present use of bitumen
Modern application of bitumen is:
- roofs and foundations sealing during building works;
- isolation material for pipe laying;
- building material for paving operations.
Bitumen is quite actively used for production of various paintwork materials, electric cables, batteries, protective layer for oil and gas wells, and for protection from radiation and microorganisms for various materials.
Bitumen storage and shipment
Bitumen is stored in special reservoirs which are usually equipped with heating and mixing devices.
Bitumen is transferred through pipes equipped with pumps. Bitumen can be shipped in the state of liquid. Also, there are different forms for bitumen transportation in its solid state.
Although bitumen is characterized by good operation features, researches in improving its quality, increasing its scope of application and recycling methods do not stop.
It is explained by the fact that requirements to building materials are getting more and more demanding. Also the demand for service life of bitumen road surface is increasing, with the amount of cars and traffic intensifying in the last decades.
In order to meet challenges of building better roads, the bitumen is being improved – modified with special additives.
GlobeCore manufactures equipment for bitumen modification with polymers. UVB-2 devices (productivity from 4 to 22m3/h) for production of modified bitumen, including polymer-bitumen binders, which are used as top layer of asphalt concrete, road-surface treatment, protective layers for concrete/cement , and for the bituminous-elastomeric sealant and roof waterproofing.
The quality of the bitumen modified on UVB-2 devices fully comply with the world standards. GlobeCore equipment can be successfully used both in the open air under sheds and in the buildings fitted with combined extract and input ventilation.