This article talks about bitumen components, history, production, types, and grades, such as cutback bitumen types, PEN grades, Performance grades, and emulsions. Generally speaking, bitumen includes hydrocarbons and elements such as calcium, iron, sulfur, and oxygen.
It is important to know that the quality and the specification of the substance is highly related to the quality of the crude oil, from which bitumen emerges.
Most of the bitumen grades are mainly appropriate for road paving and construction. However, some of them are also good for waterproofing coatings. As a matter of fact, many roads in the United States are of either bitumen or a combination of bitumen and aggregates, such as concrete.
History of cutback bitumen and other types
Before bitumen becomes popular and well known among the people, tar was the basic substance which acted as a binder material for bituminous matters. After the 20th century, new sorts of vehicles with pneumatic tires came to the market in the UK. People of that time constructed roads by the application of water-bound and graded aggregates.
Bitumen production and structure
The manufacture of bitumen is a complicated process about which we tend to explain briefly. Chemically speaking, bitumen is a residual substance. The refined bitumen specifications depend on the process type, the extent of extraction, the viscosity, and the distillation method. All these mentioned factors will result in the production of different bitumen types such as cutbacks, emulsions, and others.
The hydrocarbons formed in a complicated colloidal order will form the bitumen structure.
To be more specific, bitumen is a colloidal system that diffuses in trichloroethylene.
This solution determines the constituents that are present in the bitumen. The bitumen constituents divide as follows:
Asphaltenes and Maltenes.
Cutback bitumen properties
The advantage of Cutback bitumen over emulsion is the existence of a much higher residual bitumen percent, typically over 80% compares with over 40-65% for emulsions. Bitumen emulsion is suitable for ambient temperature, while cutback bitumen must be heated to 160°C which cause the loss of thermal energy and fuel. Besides, we can apply bitumen emulsion on wet (not full of water) surfaces, unlike cutback bitumen which necessitates a totally dry surface.
It is worth mentioning that cutbacks divide into three main classifications,
Rapid-Curing (RC) and Medium-Curing (MC), and Slow-Curing (SC) depending on the solvent.
Each of these mentioned types has several sub categories that each has a specific feature.