Driving along I-20 West in Mississippi, I noticed the pavement is a warm dark brown color instead of the typical black asphalt. Anyone know why?
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I don't know... but I found it through research! I can't believe I actually found an answer for this one. :-)
The asphalt color mostly has to do with the type of locally-obtained aggregate that's used. Mostly brown when it's dredged out of a river, mostly gray when it comes from a quarry, and mostly white when there are seashells involved, such as Florida. It may all start out as a darker black color, but as it weathers and fades, it becomes what you see, the more colorful rainbow of the asphalt world...
Since you're talking about western Mississippi, near the... Mississippi River, I imagine that they may have used a lot of dredged sediment and/or the dry area that the aggregate came from is from loose rock laid down by centuries upon centuries of flooding.
In areas of Pennsylvania, where rock is primarily sedimentary, some of the roads used an aggregate of red shale, which weathers and fades to a pinkish color. Some people have noted that along I-20, the brown asphalt generally exists near the Tennessee and Mississippi Rivers, except around Knoxville where it's mostly gray.
There's a whole bulletin board of people talking about roads and asphalt, if you'd like to see more. Link below.
The asphalt color mostly has to do with the type of locally-obtained aggregate that's used. Mostly brown when it's dredged out of a river, mostly gray when it comes from a quarry, and mostly white when there are seashells involved, such as Florida. It may all start out as a darker black color, but as it weathers and fades, it becomes what you see, the more colorful rainbow of the asphalt world...
Since you're talking about western Mississippi, near the... Mississippi River, I imagine that they may have used a lot of dredged sediment and/or the dry area that the aggregate came from is from loose rock laid down by centuries upon centuries of flooding.
In areas of Pennsylvania, where rock is primarily sedimentary, some of the roads used an aggregate of red shale, which weathers and fades to a pinkish color. Some people have noted that along I-20, the brown asphalt generally exists near the Tennessee and Mississippi Rivers, except around Knoxville where it's mostly gray.
There's a whole bulletin board of people talking about roads and asphalt, if you'd like to see more. Link below.