Information AboutAsphalt |
| CATEGORIES ABOUT ASPHALT | |
| building materials | |
| petroleum products | |
| recyclable materials | |
| road construction | |
| chemical mixtures | |
|
Asphalt is a sticky, black and highly Viscous liquid or semi-solid that is present in most crude Petroleum s and in some natural deposits. Asphalt is composed almost entirely of Bitumen . There is some disagreement amongst Chemist s regarding the structure of asphalt, however it is most commonly modeled as a Colloid , with ''asphaltenes'' as the dispersed phase and ''maltenes'' as the continuous phase. Asphalt is sometimes confused with Tar , which is an artificial material produced by the Destructive Distillation of Organic Matter . Tar is also predominantly composed of bitumen, however the bitumen content of tar is typically lower than that of asphalt. Tar and asphalt have very different engineering properties. Asphalt can be separated from the other components in crude oil (such as . This makes the product harder and more viscous. Natural deposits of asphalt include Lake Asphalts (primarily from the Pitch Lake in Trinidad And Tobago and Bermudez Lake in Venezuela ), Gilsonite , the Dead Sea in Israel , and Tar Sands . Asphalt is rather hard to transport in bulk (it hardens unless kept very hot) so it is sometimes mixed with Diesel Oil or Kerosene before shipping. Upon delivery, these lighter materials are separated out of the mixture. This mixture is often called bitumen feedstock, or BFS. The largest use of asphalt is for making Asphalt Concrete for Pavement s, which accounts for approximately 80% of the asphalt consumed in the United States . Roof ing Shingle s account for most of the remaining asphalt consumption. Other uses include Cattle Spray s, fence post treatments, and waterproofing for fabrics. While Americans are accustomed to thinking about Recycling their newspapers and beverage containers, the most widely recycled product in terms of both percentage and tonnage is actually asphalt pavement. According to a report issued by the Federal Highway Administration and the United States Environmental Protection Agency , 80 percent of the asphalt pavement that’s removed each year during widening and resurfacing projects is reused as part of new roads, roadbeds, shoulders and embankments. In the ancient Middle-east natural asphalt deposits were used for Mortar between bricks and stones, ship Caulk , and waterproofing. The Persian word for asphalt is ''mumiya'', which may be the source for the English word Mummy . REFERENCES Barth, Edwin J., ''Asphalt: Science and Technology'' Gordon and Breach (1962). ISBN 0677000405. EXTERNAL LINKS |
|
|