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Posted by Steve on April 5, 2008, 9:10 pm
alt.building.construction:
> Anyone know what is the difference between tarmac and asphalt?
Tarmac is a construction technique where tar is added to the standard
Macadam process for building a dirt road. Macadam, in a nutshell, is large
gravel covered with smaller gravel covered with even smaller gravel
covered with sand or dirt and all packed down firmly.
Asphalt is a chemical mixture of hydrocarbons that is very close to solid
at outdoor temperatures. It's what's left over after all the gasses and
liquids are removed from petroleum. If you mix hot asphalt with gravel and
sand, you get what my brother-in-law the architect calls "asphaltic
concrete" (as opposed to "cementitious concrete"). He also insists that I
not call it a "hot water heater", because there's no need to heat hot
water -- it's a "water heater". I like him anyway.
"Tarmac" is sometimes used to refer to asphaltic concrete; it's also used
to refer to the part of the airport where they park airplanes. Picky
people will tell you these are wrong, but the use is very common.
Note: These are layman's definitions from working in the oil field and
from long-ago college chemistry classes. If you want the technical ones,
you'll have to do your own search.
--
Steve B.
New Life Home Improvement
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