Why do older highways have pavement colored like a brownish yellowish color? It appears to be asphalt type pavement anyone familiar with this type of pavement? Thanks!
Steve
If everything seems under control, you're not going fast enough!
Hi Steven
It looks like you are discovering one of the interesting aspects of the hobby, that is — asking questions about "Why is that like this? or How was this done back-in-the-day?"
That's a good thing! Curiosity is what keeps us going!
When it comes to colors of common building materials a big contributing factor is — what raw materials were available, cheaply, in a particular area.
When I look at some of the old concrete structures around my area it all has a tan/yellow hue. On closer inspection you can see that the sand and aggregate used then was a very tiny pebble-like "sand" but not like what is used today. It was more rounded and had a definite brown/tan/yellow color.
Asphalt was at one time a by-product made with lots of slag from steel mills. Sometimes it would still have traces of iron-oxide in it. As the bituminous layer wore away the slag would be exposed and the iron in the mix would show its oxide-red color. Slag was practically "given away" at the steel mill.
Again, depends on where the supplier got his material and the local environment where the material was used.
Another variation when looking at "vintage" color photos is all the changes that may have occurred to the image. Lighting, fading, film type, processing variables and a whole bunch of other factors enter into the mix.
Look back at some threads about "What color is Brunswick Green" or similar discussions and you'll find out just how subjective a subject color perception is.
One thing I'll point out about our models is that most of the time our layout lighting is less-than ideal so most colors could stand to be lightened up a bit. I rarely use "jet black" color and paint mostly using shades of dark gray where black might be used. It helps to bring out details, too.
Good Luck, Ed
"Asphalt concrete pavement mixes are typically composed of 5% asphalt cement and 95% aggregates (stone, sand, and gravel). Due to its highly viscous nature, asphaltcement must be heated so it can be mixed with the aggregates at the asphalt mixing facility."
Color due to the color of the aggregates. I have seen redish asphalt in southern California desert.
I tried to sell my two cents worth, but no one would give me a plug nickel for it.
I don't have a leg to stand on.
Here's two pictures of the stuff I'm thinking of...
I can only see the bottom photo. I get a 404 on the top one.
However, in photo two you can see your answer. The aggregate on either side of the road looks like the predominant stone for that area. That's what the asphalt manufacturer is going to use. It is going to make the same color asphalt once the aggregate becomes exposed.
Like Dave mentioned, I recall seeing red pavement in areas of Nebraska and Kansas back in the 1960s. I'll bet there's plenty of Red Georgia Clay in many of the stone products from that area.
http://www.lonestarpavingtx.com/colored-asphalt/
A good many of the older asphalt concrete paved roads in my area are very light gray, nearly white, I suppose due to a large amount of limestone in it.
Regards, Ed
The first had the same color but was in Louisiana... another example would be the old race surface at Talladega... it also seems new asphalt is more black or is that another format of pavement known as "Blacktop"?
Here's another examples...
Race tracks might not make a good comparison? The pavement specifics may not be the same as what is specified for Department of Transportation specs.
http://wwwsp.dotd.la.gov/Inside_LaDOTD/Divisions/Engineering/Standard_Specifications/Pages/Standard%20Specifications.aspx
Have Fun... Ed
True I was just trying to show the color I was speaking of...
Steven,
Is there any chance of posting larger (e.g. 500px x 500px and > but < than 1,000px x 1,000px) photos? If you left click on the original photo (to enlarge it) and copy the URL from that one, you get a larger picture. The photos you are posting are essentially the same size when you click on them.
Here's an example of what I'm saying:
200px x 200px
vs
1,152px × 864px
It makes it easier to see details. Just a suggestion...
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Some of that can be wear and weathering as well. Look at the picture of the paved road that is nearly yellow on the surface - look at the cracks where fresh material shows through. Surface is rather yellow, but as can be seen by the cracks, the material under the surface layer is pretty much black.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
It all comes down to the color of the local materials used, and the weathering affects, of the sun, time, and wear. Use any recently paved road in your area, that you travel on a lot. Notice how nice, new, and black the asphalt is. Look at it a couple of years later, now "weathered" to a dull grayish color.
Concrete is the same. No difference if it's your new sidewalk or patio. Newly cured, it's nice and white and clean looking. A couple years later?
I've always like the asphalt and concrete in northern WI., because of the multi-colored crushed granite used for the aggregate. Concrete up there makes a great exposed aggregate finish right out of the truck.
Mike.
My You Tube
I was able to get close up to the pavement in question, it appears to be concrete poured like asphalt, it is cracking in the fashion that asphalt would but appears to be concrete like, could it be asphalt with a high sand/cement content and low tar content?
I'll post a picture later...
.
As several have said already, asphault is the color of the local aggregate.
Aggregate is the stone that is mixed with the asphault "tar" binder that holds it all together.
Here in South Florida the asphault roads are almost white. Because of this we need to stripe the roads with alternating black and white lines, not just white like in most areas. White lines disappear on our roads.
When the road is freshly formed, it is solid black. Soon the "tar" wears away and the aggregate is exposed. In my case that is white limestone.
Some of the prettiest roads you will ever see are near Elberton, Georgia where they have some magnificent granite quarries. The granite in the roads there actually make them sparkle. It is a very neat thing the first time you see it.
If the predominent material in the area is red sandstone, that is probably the color the road will be. It is too expensive to truck in the aggregate, so whatever is local is used.
Other factors effect road appearance. This is all way too deep to get into here.
For your layout, go with what looks right. You can't go wrong with good old medium gray.
-Kevin
Living the dream.
So it'll be the color of predominant aggregate available... here in LA it's mostly river gravel light tans/browns, some yellow/orange...
Got it thanks!
Today we went to Mississippi to just go riding, one of the highways we went on was a red/orange/brown kinda a rust/oxide color which makes sense because the gravel in the area has more red to it.
NWP SWP Here's another examples...
Here's another curiosity question, was crushed brick ever used as aggregate for asphalt? That'd make an interesting looking road!
The color of the soil surrounding the pavement will also affect the color, especially in dry, windy regions. Notice the color change after a strong rain has removed some of the dust that gets ground into the aggregate surface.
NWP SWPHere's another curiosity question, was crushed brick ever used as aggregate for asphalt?
I can't say for sure but I doubt it. Brick is not as hard as stone. However, in the Carrizo Gorge I saw ballast composed of broken firebricks mixed with cinders.
I would be very surprised if it has not been somewhere. I doubt it is done very often. It would be difficult to tell by looking at the road. I doubt you could tell if the aggregate was cruched brick or red stone.
This is what a newly paved road looks like:
You can see it is nearly pure black. This will not last long.
This picture shows a strip of asphault six months old leading to the new pavement. The older section of the road is lighter gray and much older. Three colors af blacktop all within a few feet.
This is a close-up of the new pavement:
This is the older road:
You can see that the aggregate color is showing in the older road. This is even more obvious at the point where the sections adjoin:
Look at this crazy sidewalk. There is a fresh concrete section, old concrete, and pavers onn the side closest to the camera. This would look terrible on a model railroad scene.
Keven,
I believe the pavers are concrete that has had a mold pressed into it to make it look like pavers. It would be interesting to see what it looks like in a few years.
I thought of a good material to use as a road surface, a fine grit sand paper! With a coat of paint it would look pretty convincing IMO...
Color would also depend on the paving type. I don't know the names but in one they put a layer of tar down and then spread what ever gravel they are using for the surface. later they come back and sweep the loose gravel up. You would have the color of the gravel from the start. This is the cheapest and doesn't last near as long. The other is where the gravel and bitumen is mixed at a plant and transported to the construction site where it is laid and rolled. This is the method most used today. It last longer.
Other than brand new pavement that is uniformly black, any road with some age on it will show several colors from dark to light that will give it some visible texture. How do you replicate that texture (in any color)? I would think that lightly painting fine sandpaper with a thin wash then rubbing it when dry might give it some of that textured look. Anyone tried that?
Paul D
N scale Washita and Santa Fe RailroadSouthern Oklahoma circa late 70's