Asphalt vs. Concrete

[Sleeping Giant]

Around MD, asphalt is a much more common paving material than concrete. But I'm curious to know the differences between the two. One must have some advantages over the other, otherwise the other would always be used, and the one never would. Which is cheaper to pave with? Which lasts longer? Which is easier to repair? Which gives better traction?

 

[Luis G]

Asphalt feels smoother, but i think concrete lasts longer.

Around here all roads are made with asphalt, in the northern states they're made of concrete. Perhaps concrete is more suitable for the desert, who knows

 

[Professur]

There's also tarmac, which doesn't put up with high heat very well.

 

[unclehobart]

I'm sure its based upon its cooperation with extreme lows in temperature and the way ice expands and can degrade asphalt all too easily by pushing it all apart in time. The tar base may also suffer somewhat. Concrete is more seamless and predictible a medium to tinker with.

 

[Gonz]

Concrete is stronger but less durable.

 

[Leslie]

there's Astroturf too...

betcha Nixy knows this one

 

[freako104]

depends on the part of md you are in. Glen Burnie is in PG county. Montgomery Co(where I grew up) i remember havng some more concrete tho not much. ariound here its all asphalt

 

[Sleeping Giant]

Just for the record, Glen Burnie is in Anne Arundel County, not Prince George's. But I didn't specifically mean Glen Burnie, although I was on I-97, a concrete surface highway, when it occurred to me that most of the other highways I'm familiar with around MD are asphalt (I-95, most of I-695, various other state highways and roads).

 

[freako104]

whoops my bad sorry. i dont travel south of DC much(except for Va or school or vacation etc) so i havent been to PG or Ann Arundel in a long assed time. try 355 or 270. 495 is asphalt i think i am nt sure since i havent seen it in a long time

 

[Inkara1]

Isn't asphalt also cheaper than concrete?

 

[Mirlyn]

I think its cheaper and somewhat easier to lay than concrete while concrete is more susceptible to cracking than asphalt is.

 

[freako104]

Isn't asphalt also cheaper than concrete?

i believe it is yes

 

[dAbeaRs]

concrete is much better. period. if this world were not money-driven every road would be cement. Lasts longer, virtually no maitence, holds more weight, and near the end of life can be TOPPED with asphalt to extend life.

Asphault is used in subdivisions and small streets where constant heavly load is not present and therefore does not require heavy-duty materials. Asphault is softer than concrete, and yes you can feel the difference. It is also very tacky when dry, but concrete is better than asphault when wet. Ever noticed traffic light intersections are kept plain concrete? it helps hold heavy traffic and provides more safety during bad weather.

Of course asphault is cheaper to install and it is the reason you dont normally see concrete patchwork.... though they are making a stride in northern illinois lately....

 

[Sleeping Giant]

Ever noticed traffic light intersections are kept plain concrete?

No, I've never noticed that, in actually can't recall ever having seen a concrete intersection of asphalt streets. That's not something they do around here. I guess it's a regional thing.

I would have guessed that asphalt provided more traction, I guess because it looks rougher.

 

[A.B.Normal]

Some of the roads out here are a Special Asphalt thats pourous and let the water seep through it,don't think concrete would be able to do that. Concrete does not stand up to the use of salt like Asphalt and around here they salt the roads plenty during the winter.

 

[Sleeping Giant]

I have heard of the porous asphalt, although I'm not aware of it being widely used around here. The only place I actually know where it's been used is on a Royal Farms parking lot (to those without Royal Farms, think 7-Eleven, Highs, Wawa, Circle-K, etc.). There's a sign on one of the light posts that announces porous asphalt was used to pave the parking lot, and warns not to dump anything on it.

On a side note, there is another asphalt variation that they used to use in Baltimore City, but I think they don't use it too much anymore. This asphalt variation incorporated pieces of recycled glass in the aggregate material. Obviously, something was done so that the glass wouldn't puncture tires. The effect of the glass was that, at night, the glass reflected light which seemed to make the road look like the road itself was lit. It seemed to me, thought, that this effect would have been more useful where there was less ambient light to begin with.

On a different side note, there's a stretch on Rt. 100, about a quarter-mile long, where between the fast and middle lanes, there are reflectors embedded in the road in the spaces between the white lines. Reflectors embedded in the roadway are not unusual here, but what makes these noteworthy are that there are about ten of them between each white line dash. But what's even more unusual is during the last several white line dashes, instead of embedded reflectors, there are actual little glowing things. I don't know what they actually are but they look like blue LEDs. And since there are about ten of these between each white line dash, they go by so fast as to give a very erie effect. This is the only place I have ever seen this and it only lasts a few hundred feet, or less (for the lights). There's nothing special about that part of the road, it's just like any other roadway as far as I can tell. The only thing even remotely unusual is that it happens to be about directly under a common landing path for airplanes to BWI, and the planes are only a few hundred feet AGL at that point, but I can't imagine any connection between this and the little glowing lights on the road between the white line dashes.

 

[Inkara1]

That reminds me; I found out a little while back that a blue dot on the street means there's a fire hydrant on the side of the street right there. It makes perfect sense (so fire crews can find the hydrant before getting near it even if parked cars block their view), but I'd never made the connection before.

 

[A.B.Normal]

Useless fact: The official name for one who installs the reflectors on roadways as Sleeping Giant described above is ......


















Wait for it .......




















Butt layer saw that on Johnny Carson many years back and for some reason it stuck with me.

Just call me Cliff

 

[Mirlyn]

That reminds me; I found out a little while back that a blue dot on the street means there's a fire hydrant on the side of the street right there. It makes perfect sense, but I'd never made the connection before.

Jeeze....here they just paint the fire hydrant....

 

[greenfreak]

A lot of the fire hydrants here have little poles with red flags on them now. Why? So when the snow plows bury them, you can still see where they are.

I noticed a lot more concrete roads when I drove down to Florida. It seemed like the warmer the area, the more concrete I saw. Which would make sense if it doesn't hold as much heat as asphalt does.

There are something like 6 old old highways on Long Island that were paved with concrete originally. But as it degrades over the years, they pave over it with asphalt. Every day I drive this one road with mixed concrete and asphalt sections and the noise difference is pretty apparent. The concrete sections are much louder.