Asphalt is a viscous, sticky and black colored material used as a binder in asphalt mixtures for the construction of roads, highways or freeways. It is also used in waterproofing. Is present in crude oil and composed almost entirely debitumen. Its name recalls the Lake Asfaltites (the Dead Sea) in the Jordan River Basin.
In addition to the mentioned site is in natural state forming a complex mixture of solid hydrocarbons in some gaps oil basins, as in the lake Guanoco asphalt, lake asphalt largest in the world (Sucre State, Venezuela), with 4 km ² of extension and 75 million barrels of natural asphalt. Next in size and importance Lake La Brea asphalt on the island of Trinidad.
Despite the easy operation and excellent quality of natural asphalt, not usually exploited long since, obtained from petroleum refineries as a solid product in the cracking or fragmentation that occurs in the distillation towers, it is much cheaper obtaining in this way. Something similar happens with getting the gas, which is also an almost undesirable byproduct in the process of getting gasoline and other petroleum products.
As the asphalt is a waterproof, adhesive, cohesive, capable of withstanding high instantaneous effort and flow under the action of permanent loads material, it presents the ideal properties for the construction of pavements performing the following functions:
Waterproof the pavement structure, making it very sensitive to moisture and efficiently against the penetration of water from precipitation.
Provides an intimate union and cohesion between aggregates, able to withstand the mechanical action of disintegration produced by vehicle loads. Also improves the bearing capacity of the structure, allows to reduce its thickness.