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Bitumen typically contains, elementally 80% by weight of carbon; 10% hydrogen; up to 6% sulfur; and molecularly, between 5 and 25% by weight of asphaltenes dispersed in 90% to 65% maltenes. [18] Most natural bitumens also contain organosulfur compounds, nickel and vanadium are found at <10 parts per million, as is typical of some petroleum. [6]
Pitch produced from petroleum may be called bitumen or asphalt, while plant-derived pitch, a resin, is known as rosin in its solid form. Tar is sometimes used interchangeably with pitch, but generally refers to a more liquid substance derived from coal production, including coal tar , or from plants, as in pine tar .
The main difference between the two processes is the equipment used to break the concrete pavement and the size of the resulting pieces. The theory is that frequent small cracks will spread thermal stress over a wider area than infrequent large joints, reducing the stress on the overlying asphalt pavement.
Bituminous waterproofing systems are designed to protect residential and commercial buildings. Bitumen (asphalt or coal-tar pitch) is a material made up of organic liquids that are highly sticky, viscous , and waterproof. [ 1 ]
While the primary distinction between bitumen and pyrobitumen is solubility, the thermal processes driving the molecular cross-linking also decrease the atomic ratio of hydrogen to carbon from greater than one to less than one and ultimately to approximately one half. It should also be understood that both solubility and atomic H/C ratios form ...
Bituminous coal was once extensively used for home heating in the US. However, bituminous coal is a relatively dirty fuel. The reduction in the use of bituminous coal between 1945 and 1960 is estimated to have saved at least 1,923 lives of all ages and 310 infant lives per winter month. [62]
"Tar" and "pitch" can be used interchangeably.Asphalt (naturally occurring pitch) may also be called either "mineral tar" or "mineral pitch". There is a tendency to use "tar" for more liquid substances and "pitch" for more solid (viscoelastic) substances. [2]
The Orinoco Belt in Venezuela is sometimes described as oil sands, but these deposits are non-bituminous, falling instead into the category of heavy or extra-heavy oil due to their lower viscosity. [6] Natural bitumen and extra-heavy oil differ in the degree by which they have been degraded from the original conventional oils by bacteria.