BITUMEN – is product of black color with a density of about one, with a low thermal and electrical conductivity. It perfectly resists various chemicals, water, and gas-tight, resistant to different types of radiation and prolonged heat impact action. It is such a valuable quality of bitumen combined with low cost and mass production have made them indispensable in many areas of the economy. Being amorphous material, bitumen has melting point. The transition from the solid to the liquid state is characterized by a softening temperature, which is usually determined on the “ring-and-ball.” The hardness of bitumen is estimated by measuring the penetration and ductility – elongation (ductility). Harmonised European standards exist for most types of bituminous binders, the applicable specifications for bituminous binders in Europe are:Naturally occurring asphalt/bitumen is sometimes specified by the term “crude bitumen”. Its viscosity is similar to that of cold molasses while the material obtained from the fractional distillation of crude oil boiling at 525 °C (977 °F) is sometimes referred to as “refined bitumen”. The Canadian province of Alberta has most of the world’s reserves of natural bitumen, covering 142,000 square kilometres (55,000 sq mi), an area larger than England. The components of asphalt are classified into four classes of compounds:
- saturates, saturated hydrocarbons, the % saturates correlates with softening point of the material
- Naphthene aromatics, consisting of partially hydrogenated polycyclic aromatic compounds.
- Polar aromatics, consisting of high molecular weight phenols and carboxylic acids
- Asphaltenes, consisting of high molecular weight phenols and heterocyclic compounds