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Plastic Roads Sound Like a Crazy Idea, Maybe Aren't
schwit1 writes with news that the Dutch city of Rotterdam is looking at partnering with a company called VolkerWessels to test a prototype plastic road for safety and durability. "They envision pulling waste plastic out of the oceans, and then processing it into prefabricated sections of road with integrated utility channels and drainage. The composition and structure of the plastic makes it more durable than traditional asphalt, and VolkerWessels estimates that their plastic roads should last about three times as long as traditional roads." The roads are manufactured at a factory, and then hauled in a mostly finished state to where they'll end up. This could dramatically reduce the time during which drivers are inconvenienced by road construction efforts.
I've read the assertion that plastic roads sound like a crazy idea elsewhere, too. I don't think this ideas is crazy at all. Why would it be? We currently pave roads with asphalt which we get from crude oil. It makes sense to me that if we process the crude (or some other oil or source of hydrocarbons; say, recycled plastic) we can make something that works similarly well or even better.
Please correct me if I got my facts wrong.
How will these plastic road segments hold up to the kinds of expansion and contraction roads undergo during especially hot or cold days?
Will they be have to be melted together to prevent cracks between segments for weatherproofing against rain, snow and ice? (Water expands when frozen, remember)
And how well will they stack up against some idiot driving along on a rim with no tire?
Will they be fireproof? One flaming car wreck and you've got a wall of fire that goes on for miles, spewing toxic smoke.
Anyone see what just happened in California? Can't imagine the practical road damage and amazing environmental damage of tons of plastic on fire.
Unless you're the company selling the idea in the first place. What it sounds like to me is expensive and pointless. Isn't asphalt reusable? Scoop it up, reheat it, pave with it again? By all means have someone start cleaning up the oceans and recycling all the plastic waste out there, but not this way.
Are YOU using the TOOL, or is the TOOL using YOU? Think about it!
Unless these road pieces are chemically altered in some way, traction on plastic roads would be awful. And shards of the roads that break off under wear and tear are going to be blown out into nature, poisoning the environments they land in over time.
I'm all for cleaning out the oceans, but this seems like moving toxic, nature-insoluble trash from one environment to another. Permanently ridding ourselves of the plastic is the right path.
Finally a car analogy I can understand.
Pothole in plastic? Pour molten plastic in? Buy a new section of road?
Potholes form in asphalt when water settles into slight depressions. The water softens the asphalt, and then traffic deepens the depression, allowing more water to settle. Freezing and thawing makes it even worse. The plastic road in TFA is perforated, so water drains into a series of tubes. So potholes should not form in the first place. Even with asphalt, potholes can be greatly reduced with proper grading, and by adding fiber.
But I don't think this plastic road is a serious proposal. They may build a few hundred meters as a PR stunt. You cannot collect plastic from the sea cost effectively, and you aren't going to make a good road surface out of random trash.
The idea of pulling plastic out of the oceans is senseless to anyone who gives the idea a minute of thought. Do these people have any idea how big the ocean is and how small the particles of plastic can be?
Even if we assume that they have magically found a way to get and recycle the plastic garbage in a few bazillion cubic meters of ocean, they'll still have to do better with the end result than experiments so far. The Morrison Bridge in Portland OR has a skid resistant polymer deck that is already coming apart after just a couple years. I wouldn't write this idea off a priori but there major problems to overcome.
They should make the road Lego compatible. Studded tires would work then.
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http://www.theoceancleanup.com... is the curent page for the project Boyan Slat started that got some coverage back arround 2013 http://www.dailymail.co.uk/sci...
Here in Arizona we are laying a lot of rubber roads: more durable, quieter, and no more mountains of old tires. It's like driving on carpet. But in accidents, they can catch fire.
One time when I visited Rotterdam (wonderful people and a great city, btw) I saw some street construction near the hotel I stayed in. The street was paved with bricks. Instead of using a jackhammer to get through the street's surface, the workers just dug up the bricks, did their work, smoothed out the surface and re-installed the bricks. When they were done, it looked like they were never there. So it seems more like a matter of replacing those bricks with plastic ones, as bricks are already being used for road surfaces.
They are also a little more dangerous for heavy trucks. A friend drives a 16-wheel dump truck with pushers and a strongarm, and apparently if he has to panic-stop the rubberized-asphalt roads are more prone to surface melting and turning to liquid under the tires, effectively making the truck hydroplane in otherwise dry conditions. Nothing like fifteen tons of uncontrollable truck sliding at freeway speeds toward a stupid motorist that cut-off the truck...
I've also noticed they're not nearly as durable as the hard concrete surfaces they replace. There are stretches on most of the oldest coated roads like the I-17 around the Durango Curve and on the US-60 where it diverges Eastbound from the I-10 where the coating has been scraped off in patches, and there are other sections where the coating has split above the control joints in the underlying concrete, making the road noisy again.
I won't deny they're beautifully quiet when new, but they just don't age very well.
Do not look into laser with remaining eye.
As this is an article about Dutch roads. Most highways here have a top layer of asphalt; this is a mix of materials which include: rubber, plastics, stone, zand, and a tar like binding agent called bitumen.
It is designed to make highways be able to drain water, have a rough structure for grip on tires and to reduce noise pollution, and handle the temperature and humidity changes of the Dutch climate.
https://nl.wikipedia.org/wiki/Zeer_Open_Asfalt
There are some pictures of the top layers of a Dutch highway. And lots of text in Dutch, but no link to an english page.
As I mention that asphalt layer is only the top 7 cm of a highway, below it are:
- 3 layers of 6 cm each of asphalt/concrete slabs
- 30 cm of unbounded foundation
- 70 cm of sand
Below this a foundation of Styrofoam blocks may be used on very soft ground to reduce sagging.
I live in New England. We have lots of freeze-thaw cycles during the year. It's rare that you see a proper frost heave in a road (and you certainly know it when you see it). By FAR the most road damage is caused by inexpert patching of the asphalt where the surface needs to be cut for utility work. When inexpertly patched, the surface is no longer remotely planar, and the unevenness right at the (and caused by the) patch increases the wear exactly where it can do the most damage. So, shortly, the patch needs a patch. Which is inexpertly done, and the cycle continues until you get a stretch of crud for surface and the local municipality shells out big bucks to have the road re-surfaced entirely.
Compare this to Southern California (where I lived for a number of years) where the road patches after utility work are 100% as smooth as the original surface. With your eyes closed, you cannot tell that you've driven over a patch. The patch (and especially the transitions from original surface to patch, and back) receives no more or less force than the original road, so there's no focus of wear, and it lasts a very long time.
It baffles me why we can't make proper road patches in New England. It's clearly possible. And I really can't believe that the people working to patch roads in Southern California are that much more talented, so it's either a technology issue, lack of managerial directive, or an out-and-out conspiracy to have a never-ending amount of road resurfacing work.
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